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  • puma init.d for centos 6 fails with runuser: user /var/log/puma.log does not exist

    - by Rubytastic
    Trying to get a init.d/puma to work on Centos 6. It throws error runuser: user /var/log/puma.log does not exist I run this from the /srv/books/current folder but it fails. I tried to debug the values but not quite get what is missing and why it throws this error. #! /bin/sh # puma - this script starts and stops the puma daemon # # chkconfig: - 85 15 # description: Puma # processname: puma # config: /etc/puma.conf # pidfile: /srv/books/current/tmp/pids/puma.pid # Author: Darío Javier Cravero &lt;[email protected]> # # Do NOT "set -e" # Original script https://github.com/puma/puma/blob/master/tools/jungle/puma # It was modified here by Stanislaw Pankevich <[email protected]> # to run on CentOS 5.5 boxes. # Script works perfectly on CentOS 5: script uses its native daemon(). # Puma is being stopped/restarted by sending signals, control app is not used. # Source function library. . /etc/rc.d/init.d/functions # Source networking configuration. . /etc/sysconfig/network # Check that networking is up. [ "$NETWORKING" = "no" ] && exit 0 # PATH should only include /usr/* if it runs after the mountnfs.sh script PATH=/usr/local/bin:/usr/local/sbin/:/sbin:/usr/sbin:/bin:/usr/bin DESC="Puma rack web server" NAME=puma DAEMON=$NAME SCRIPTNAME=/etc/init.d/$NAME CONFIG=/etc/puma.conf JUNGLE=`cat $CONFIG` RUNPUMA=/usr/local/bin/run-puma # Skipping the following non-CentOS string # Load the VERBOSE setting and other rcS variables # . /lib/init/vars.sh # CentOS does not have these functions natively log_daemon_msg() { echo "$@"; } log_end_msg() { [ $1 -eq 0 ] && RES=OK; logger ${RES:=FAIL}; } # Define LSB log_* functions. # Depend on lsb-base (>= 3.0-6) to ensure that this file is present. . /lib/lsb/init-functions # # Function that performs a clean up of puma.* files # cleanup() { echo "Cleaning up puma temporary files..." echo $1; PIDFILE=$1/tmp/puma/puma.pid STATEFILE=$1/tmp/puma/puma.state SOCKFILE=$1/tmp/puma/puma.sock rm -f $PIDFILE $STATEFILE $SOCKFILE } # # Function that starts the jungle # do_start() { log_daemon_msg "=> Running the jungle..." for i in $JUNGLE; do dir=`echo $i | cut -d , -f 1` user=`echo $i | cut -d , -f 2` config_file=`echo $i | cut -d , -f 3` if [ "$config_file" = "" ]; then config_file="$dir/puma/config.rb" fi log_file=`echo $i | cut -d , -f 4` if [ "$log_file" = "" ]; then log_file="$dir/puma/puma.log" fi do_start_one $dir $user $config_file $log_file done } do_start_one() { PIDFILE=$1/puma/puma.pid if [ -e $PIDFILE ]; then PID=`cat $PIDFILE` # If the puma isn't running, run it, otherwise restart it. if [ "`ps -A -o pid= | grep -c $PID`" -eq 0 ]; then do_start_one_do $1 $2 $3 $4 else do_restart_one $1 fi else do_start_one_do $1 $2 $3 $4 fi } do_start_one_do() { log_daemon_msg "--> Woke up puma $1" log_daemon_msg "user $2" log_daemon_msg "log to $4" cleanup $1; daemon --user $2 $RUNPUMA $1 $3 $4 } # # Function that stops the jungle # do_stop() { log_daemon_msg "=> Putting all the beasts to bed..." for i in $JUNGLE; do dir=`echo $i | cut -d , -f 1` do_stop_one $dir done } # # Function that stops the daemon/service # do_stop_one() { log_daemon_msg "--> Stopping $1" PIDFILE=$1/tmp/puma/puma.pid STATEFILE=$1/tmp/puma/puma.state echo $PIDFILE if [ -e $PIDFILE ]; then PID=`cat $PIDFILE` echo "Pid:" echo $PID if [ "`ps -A -o pid= | grep -c $PID`" -eq 0 ]; then log_daemon_msg "---> Puma $1 isn't running." else log_daemon_msg "---> About to kill PID `cat $PIDFILE`" # pumactl --state $STATEFILE stop # Many daemons don't delete their pidfiles when they exit. kill -9 $PID fi cleanup $1 else log_daemon_msg "---> No puma here..." fi return 0 } # # Function that restarts the jungle # do_restart() { for i in $JUNGLE; do dir=`echo $i | cut -d , -f 1` do_restart_one $dir done } # # Function that sends a SIGUSR2 to the daemon/service # do_restart_one() { PIDFILE=$1/tmp/puma/puma.pid i=`grep $1 $CONFIG` dir=`echo $i | cut -d , -f 1` if [ -e $PIDFILE ]; then log_daemon_msg "--> About to restart puma $1" # pumactl --state $dir/tmp/puma/state restart kill -s USR2 `cat $PIDFILE` # TODO Check if process exist else log_daemon_msg "--> Your puma was never playing... Let's get it out there first" user=`echo $i | cut -d , -f 2` config_file=`echo $i | cut -d , -f 3` if [ "$config_file" = "" ]; then config_file="$dir/config/puma.rb" fi log_file=`echo $i | cut -d , -f 4` if [ "$log_file" = "" ]; then log_file="$dir/log/puma.log" fi do_start_one $dir $user $config_file $log_file fi return 0 } # # Function that statuss then jungle # do_status() { for i in $JUNGLE; do dir=`echo $i | cut -d , -f 1` do_status_one $dir done } # # Function that sends a SIGUSR2 to the daemon/service # do_status_one() { PIDFILE=$1/tmp/puma/pid i=`grep $1 $CONFIG` dir=`echo $i | cut -d , -f 1` if [ -e $PIDFILE ]; then log_daemon_msg "--> About to status puma $1" pumactl --state $dir/tmp/puma/state stats # kill -s USR2 `cat $PIDFILE` # TODO Check if process exist else log_daemon_msg "--> $1 isn't there :(..." fi return 0 } do_add() { str="" # App's directory if [ -d "$1" ]; then if [ "`grep -c "^$1" $CONFIG`" -eq 0 ]; then str=$1 else echo "The app is already being managed. Remove it if you want to update its config." exit 1 fi else echo "The directory $1 doesn't exist." exit 1 fi # User to run it as if [ "`grep -c "^$2:" /etc/passwd`" -eq 0 ]; then echo "The user $2 doesn't exist." exit 1 else str="$str,$2" fi # Config file if [ "$3" != "" ]; then if [ -e $3 ]; then str="$str,$3" else echo "The config file $3 doesn't exist." exit 1 fi fi # Log file if [ "$4" != "" ]; then str="$str,$4" fi # Add it to the jungle echo $str >> $CONFIG log_daemon_msg "Added a Puma to the jungle: $str. You still have to start it though." } do_remove() { if [ "`grep -c "^$1" $CONFIG`" -eq 0 ]; then echo "There's no app $1 to remove." else # Stop it first. do_stop_one $1 # Remove it from the config. sed -i "\\:^$1:d" $CONFIG log_daemon_msg "Removed a Puma from the jungle: $1." fi } case "$1" in start) [ "$VERBOSE" != no ] && log_daemon_msg "Starting $DESC" "$NAME" if [ "$#" -eq 1 ]; then do_start else i=`grep $2 $CONFIG` dir=`echo $i | cut -d , -f 1` user=`echo $i | cut -d , -f 2` config_file=`echo $i | cut -d , -f 3` if [ "$config_file" = "" ]; then config_file="$dir/config/puma.rb" fi log_file=`echo $i | cut -d , -f 4` if [ "$log_file" = "" ]; then log_file="$dir/log/puma.log" fi do_start_one $dir $user $config_file $log_file fi case "$?" in 0|1) [ "$VERBOSE" != no ] && log_end_msg 0 ;; 2) [ "$VERBOSE" != no ] && log_end_msg 1 ;; esac ;; stop) [ "$VERBOSE" != no ] && log_daemon_msg "Stopping $DESC" "$NAME" if [ "$#" -eq 1 ]; then do_stop else i=`grep $2 $CONFIG` dir=`echo $i | cut -d , -f 1` do_stop_one $dir fi case "$?" in 0|1) [ "$VERBOSE" != no ] && log_end_msg 0 ;; 2) [ "$VERBOSE" != no ] && log_end_msg 1 ;; esac ;; status) # TODO Implement. log_daemon_msg "Status $DESC" "$NAME" if [ "$#" -eq 1 ]; then do_status else i=`grep $2 $CONFIG` dir=`echo $i | cut -d , -f 1` do_status_one $dir fi case "$?" in 0|1) [ "$VERBOSE" != no ] && log_end_msg 0 ;; 2) [ "$VERBOSE" != no ] && log_end_msg 1 ;; esac ;; restart) log_daemon_msg "Restarting $DESC" "$NAME" if [ "$#" -eq 1 ]; then do_restart else i=`grep $2 $CONFIG` dir=`echo $i | cut -d , -f 1` do_restart_one $dir fi case "$?" in 0|1) [ "$VERBOSE" != no ] && log_end_msg 0 ;; 2) [ "$VERBOSE" != no ] && log_end_msg 1 ;; esac ;; add) if [ "$#" -lt 3 ]; then echo "Please, specifiy the app's directory and the user that will run it at least." echo " Usage: $SCRIPTNAME add /path/to/app user /path/to/app/config/puma.rb /path/to/app/config/log/puma.log" echo " config and log are optionals." exit 1 else do_add $2 $3 $4 $5 fi case "$?" in 0|1) [ "$VERBOSE" != no ] && log_end_msg 0 ;; 2) [ "$VERBOSE" != no ] && log_end_msg 1 ;; esac ;; remove) if [ "$#" -lt 2 ]; then echo "Please, specifiy the app's directory to remove." exit 1 else do_remove $2 fi case "$?" in 0|1) [ "$VERBOSE" != no ] && log_end_msg 0 ;; 2) [ "$VERBOSE" != no ] && log_end_msg 1 ;; esac ;; *) echo "Usage:" >&2 echo " Run the jungle: $SCRIPTNAME {start|stop|status|restart}" >&2 echo " Add a Puma: $SCRIPTNAME add /path/to/app user /path/to/app/config/puma.rb /path/to/app/config/log/puma.log" echo " config and log are optionals." echo " Remove a Puma: $SCRIPTNAME remove /path/to/app" echo " On a Puma: $SCRIPTNAME {start|stop|status|restart} PUMA-NAME" >&2 exit 3 ;; esac :

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  • Upload File to Windows Azure Blob in Chunks through ASP.NET MVC, JavaScript and HTML5

    - by Shaun
    Originally posted on: http://geekswithblogs.net/shaunxu/archive/2013/07/01/upload-file-to-windows-azure-blob-in-chunks-through-asp.net.aspxMany people are using Windows Azure Blob Storage to store their data in the cloud. Blob storage provides 99.9% availability with easy-to-use API through .NET SDK and HTTP REST. For example, we can store JavaScript files, images, documents in blob storage when we are building an ASP.NET web application on a Web Role in Windows Azure. Or we can store our VHD files in blob and mount it as a hard drive in our cloud service. If you are familiar with Windows Azure, you should know that there are two kinds of blob: page blob and block blob. The page blob is optimized for random read and write, which is very useful when you need to store VHD files. The block blob is optimized for sequential/chunk read and write, which has more common usage. Since we can upload block blob in blocks through BlockBlob.PutBlock, and them commit them as a whole blob with invoking the BlockBlob.PutBlockList, it is very powerful to upload large files, as we can upload blocks in parallel, and provide pause-resume feature. There are many documents, articles and blog posts described on how to upload a block blob. Most of them are focus on the server side, which means when you had received a big file, stream or binaries, how to upload them into blob storage in blocks through .NET SDK.  But the problem is, how can we upload these large files from client side, for example, a browser. This questioned to me when I was working with a Chinese customer to help them build a network disk production on top of azure. The end users upload their files from the web portal, and then the files will be stored in blob storage from the Web Role. My goal is to find the best way to transform the file from client (end user’s machine) to the server (Web Role) through browser. In this post I will demonstrate and describe what I had done, to upload large file in chunks with high speed, and save them as blocks into Windows Azure Blob Storage.   Traditional Upload, Works with Limitation The simplest way to implement this requirement is to create a web page with a form that contains a file input element and a submit button. 1: @using (Html.BeginForm("About", "Index", FormMethod.Post, new { enctype = "multipart/form-data" })) 2: { 3: <input type="file" name="file" /> 4: <input type="submit" value="upload" /> 5: } And then in the backend controller, we retrieve the whole content of this file and upload it in to the blob storage through .NET SDK. We can split the file in blocks and upload them in parallel and commit. The code had been well blogged in the community. 1: [HttpPost] 2: public ActionResult About(HttpPostedFileBase file) 3: { 4: var container = _client.GetContainerReference("test"); 5: container.CreateIfNotExists(); 6: var blob = container.GetBlockBlobReference(file.FileName); 7: var blockDataList = new Dictionary<string, byte[]>(); 8: using (var stream = file.InputStream) 9: { 10: var blockSizeInKB = 1024; 11: var offset = 0; 12: var index = 0; 13: while (offset < stream.Length) 14: { 15: var readLength = Math.Min(1024 * blockSizeInKB, (int)stream.Length - offset); 16: var blockData = new byte[readLength]; 17: offset += stream.Read(blockData, 0, readLength); 18: blockDataList.Add(Convert.ToBase64String(BitConverter.GetBytes(index)), blockData); 19:  20: index++; 21: } 22: } 23:  24: Parallel.ForEach(blockDataList, (bi) => 25: { 26: blob.PutBlock(bi.Key, new MemoryStream(bi.Value), null); 27: }); 28: blob.PutBlockList(blockDataList.Select(b => b.Key).ToArray()); 29:  30: return RedirectToAction("About"); 31: } This works perfect if we selected an image, a music or a small video to upload. But if I selected a large file, let’s say a 6GB HD-movie, after upload for about few minutes the page will be shown as below and the upload will be terminated. In ASP.NET there is a limitation of request length and the maximized request length is defined in the web.config file. It’s a number which less than about 4GB. So if we want to upload a really big file, we cannot simply implement in this way. Also, in Windows Azure, a cloud service network load balancer will terminate the connection if exceed the timeout period. From my test the timeout looks like 2 - 3 minutes. Hence, when we need to upload a large file we cannot just use the basic HTML elements. Besides the limitation mentioned above, the simple HTML file upload cannot provide rich upload experience such as chunk upload, pause and pause-resume. So we need to find a better way to upload large file from the client to the server.   Upload in Chunks through HTML5 and JavaScript In order to break those limitation mentioned above we will try to upload the large file in chunks. This takes some benefit to us such as - No request size limitation: Since we upload in chunks, we can define the request size for each chunks regardless how big the entire file is. - No timeout problem: The size of chunks are controlled by us, which means we should be able to make sure request for each chunk upload will not exceed the timeout period of both ASP.NET and Windows Azure load balancer. It was a big challenge to upload big file in chunks until we have HTML5. There are some new features and improvements introduced in HTML5 and we will use them to implement our solution.   In HTML5, the File interface had been improved with a new method called “slice”. It can be used to read part of the file by specifying the start byte index and the end byte index. For example if the entire file was 1024 bytes, file.slice(512, 768) will read the part of this file from the 512nd byte to 768th byte, and return a new object of interface called "Blob”, which you can treat as an array of bytes. In fact,  a Blob object represents a file-like object of immutable, raw data. The File interface is based on Blob, inheriting blob functionality and expanding it to support files on the user's system. For more information about the Blob please refer here. File and Blob is very useful to implement the chunk upload. We will use File interface to represent the file the user selected from the browser and then use File.slice to read the file in chunks in the size we wanted. For example, if we wanted to upload a 10MB file with 512KB chunks, then we can read it in 512KB blobs by using File.slice in a loop.   Assuming we have a web page as below. User can select a file, an input box to specify the block size in KB and a button to start upload. 1: <div> 2: <input type="file" id="upload_files" name="files[]" /><br /> 3: Block Size: <input type="number" id="block_size" value="512" name="block_size" />KB<br /> 4: <input type="button" id="upload_button_blob" name="upload" value="upload (blob)" /> 5: </div> Then we can have the JavaScript function to upload the file in chunks when user clicked the button. 1: <script type="text/javascript"> 1: 2: $(function () { 3: $("#upload_button_blob").click(function () { 4: }); 5: });</script> Firstly we need to ensure the client browser supports the interfaces we are going to use. Just try to invoke the File, Blob and FormData from the “window” object. If any of them is “undefined” the condition result will be “false” which means your browser doesn’t support these premium feature and it’s time for you to get your browser updated. FormData is another new feature we are going to use in the future. It could generate a temporary form for us. We will use this interface to create a form with chunk and associated metadata when invoked the service through ajax. 1: $("#upload_button_blob").click(function () { 2: // assert the browser support html5 3: if (window.File && window.Blob && window.FormData) { 4: alert("Your brwoser is awesome, let's rock!"); 5: } 6: else { 7: alert("Oh man plz update to a modern browser before try is cool stuff out."); 8: return; 9: } 10: }); Each browser supports these interfaces by their own implementation and currently the Blob, File and File.slice are supported by Chrome 21, FireFox 13, IE 10, Opera 12 and Safari 5.1 or higher. After that we worked on the files the user selected one by one since in HTML5, user can select multiple files in one file input box. 1: var files = $("#upload_files")[0].files; 2: for (var i = 0; i < files.length; i++) { 3: var file = files[i]; 4: var fileSize = file.size; 5: var fileName = file.name; 6: } Next, we calculated the start index and end index for each chunks based on the size the user specified from the browser. We put them into an array with the file name and the index, which will be used when we upload chunks into Windows Azure Blob Storage as blocks since we need to specify the target blob name and the block index. At the same time we will store the list of all indexes into another variant which will be used to commit blocks into blob in Azure Storage once all chunks had been uploaded successfully. 1: $("#upload_button_blob").click(function () { 2: // assert the browser support html5 3: ... ... 4: // start to upload each files in chunks 5: var files = $("#upload_files")[0].files; 6: for (var i = 0; i < files.length; i++) { 7: var file = files[i]; 8: var fileSize = file.size; 9: var fileName = file.name; 10:  11: // calculate the start and end byte index for each blocks(chunks) 12: // with the index, file name and index list for future using 13: var blockSizeInKB = $("#block_size").val(); 14: var blockSize = blockSizeInKB * 1024; 15: var blocks = []; 16: var offset = 0; 17: var index = 0; 18: var list = ""; 19: while (offset < fileSize) { 20: var start = offset; 21: var end = Math.min(offset + blockSize, fileSize); 22:  23: blocks.push({ 24: name: fileName, 25: index: index, 26: start: start, 27: end: end 28: }); 29: list += index + ","; 30:  31: offset = end; 32: index++; 33: } 34: } 35: }); Now we have all chunks’ information ready. The next step should be upload them one by one to the server side, and at the server side when received a chunk it will upload as a block into Blob Storage, and finally commit them with the index list through BlockBlobClient.PutBlockList. But since all these invokes are ajax calling, which means not synchronized call. So we need to introduce a new JavaScript library to help us coordinate the asynchronize operation, which named “async.js”. You can download this JavaScript library here, and you can find the document here. I will not explain this library too much in this post. We will put all procedures we want to execute as a function array, and pass into the proper function defined in async.js to let it help us to control the execution sequence, in series or in parallel. Hence we will define an array and put the function for chunk upload into this array. 1: $("#upload_button_blob").click(function () { 2: // assert the browser support html5 3: ... ... 4:  5: // start to upload each files in chunks 6: var files = $("#upload_files")[0].files; 7: for (var i = 0; i < files.length; i++) { 8: var file = files[i]; 9: var fileSize = file.size; 10: var fileName = file.name; 11: // calculate the start and end byte index for each blocks(chunks) 12: // with the index, file name and index list for future using 13: ... ... 14:  15: // define the function array and push all chunk upload operation into this array 16: blocks.forEach(function (block) { 17: putBlocks.push(function (callback) { 18: }); 19: }); 20: } 21: }); 22: }); As you can see, I used File.slice method to read each chunks based on the start and end byte index we calculated previously, and constructed a temporary HTML form with the file name, chunk index and chunk data through another new feature in HTML5 named FormData. Then post this form to the backend server through jQuery.ajax. This is the key part of our solution. 1: $("#upload_button_blob").click(function () { 2: // assert the browser support html5 3: ... ... 4: // start to upload each files in chunks 5: var files = $("#upload_files")[0].files; 6: for (var i = 0; i < files.length; i++) { 7: var file = files[i]; 8: var fileSize = file.size; 9: var fileName = file.name; 10: // calculate the start and end byte index for each blocks(chunks) 11: // with the index, file name and index list for future using 12: ... ... 13: // define the function array and push all chunk upload operation into this array 14: blocks.forEach(function (block) { 15: putBlocks.push(function (callback) { 16: // load blob based on the start and end index for each chunks 17: var blob = file.slice(block.start, block.end); 18: // put the file name, index and blob into a temporary from 19: var fd = new FormData(); 20: fd.append("name", block.name); 21: fd.append("index", block.index); 22: fd.append("file", blob); 23: // post the form to backend service (asp.net mvc controller action) 24: $.ajax({ 25: url: "/Home/UploadInFormData", 26: data: fd, 27: processData: false, 28: contentType: "multipart/form-data", 29: type: "POST", 30: success: function (result) { 31: if (!result.success) { 32: alert(result.error); 33: } 34: callback(null, block.index); 35: } 36: }); 37: }); 38: }); 39: } 40: }); Then we will invoke these functions one by one by using the async.js. And once all functions had been executed successfully I invoked another ajax call to the backend service to commit all these chunks (blocks) as the blob in Windows Azure Storage. 1: $("#upload_button_blob").click(function () { 2: // assert the browser support html5 3: ... ... 4: // start to upload each files in chunks 5: var files = $("#upload_files")[0].files; 6: for (var i = 0; i < files.length; i++) { 7: var file = files[i]; 8: var fileSize = file.size; 9: var fileName = file.name; 10: // calculate the start and end byte index for each blocks(chunks) 11: // with the index, file name and index list for future using 12: ... ... 13: // define the function array and push all chunk upload operation into this array 14: ... ... 15: // invoke the functions one by one 16: // then invoke the commit ajax call to put blocks into blob in azure storage 17: async.series(putBlocks, function (error, result) { 18: var data = { 19: name: fileName, 20: list: list 21: }; 22: $.post("/Home/Commit", data, function (result) { 23: if (!result.success) { 24: alert(result.error); 25: } 26: else { 27: alert("done!"); 28: } 29: }); 30: }); 31: } 32: }); That’s all in the client side. The outline of our logic would be - Calculate the start and end byte index for each chunks based on the block size. - Defined the functions of reading the chunk form file and upload the content to the backend service through ajax. - Execute the functions defined in previous step with “async.js”. - Commit the chunks by invoking the backend service in Windows Azure Storage finally.   Save Chunks as Blocks into Blob Storage In above we finished the client size JavaScript code. It uploaded the file in chunks to the backend service which we are going to implement in this step. We will use ASP.NET MVC as our backend service, and it will receive the chunks, upload into Windows Azure Bob Storage in blocks, then finally commit as one blob. As in the client side we uploaded chunks by invoking the ajax call to the URL "/Home/UploadInFormData", I created a new action under the Index controller and it only accepts HTTP POST request. 1: [HttpPost] 2: public JsonResult UploadInFormData() 3: { 4: var error = string.Empty; 5: try 6: { 7: } 8: catch (Exception e) 9: { 10: error = e.ToString(); 11: } 12:  13: return new JsonResult() 14: { 15: Data = new 16: { 17: success = string.IsNullOrWhiteSpace(error), 18: error = error 19: } 20: }; 21: } Then I retrieved the file name, index and the chunk content from the Request.Form object, which was passed from our client side. And then, used the Windows Azure SDK to create a blob container (in this case we will use the container named “test”.) and create a blob reference with the blob name (same as the file name). Then uploaded the chunk as a block of this blob with the index, since in Blob Storage each block must have an index (ID) associated with so that finally we can put all blocks as one blob by specifying their block ID list. 1: [HttpPost] 2: public JsonResult UploadInFormData() 3: { 4: var error = string.Empty; 5: try 6: { 7: var name = Request.Form["name"]; 8: var index = int.Parse(Request.Form["index"]); 9: var file = Request.Files[0]; 10: var id = Convert.ToBase64String(BitConverter.GetBytes(index)); 11:  12: var container = _client.GetContainerReference("test"); 13: container.CreateIfNotExists(); 14: var blob = container.GetBlockBlobReference(name); 15: blob.PutBlock(id, file.InputStream, null); 16: } 17: catch (Exception e) 18: { 19: error = e.ToString(); 20: } 21:  22: return new JsonResult() 23: { 24: Data = new 25: { 26: success = string.IsNullOrWhiteSpace(error), 27: error = error 28: } 29: }; 30: } Next, I created another action to commit the blocks into blob once all chunks had been uploaded. Similarly, I retrieved the blob name from the Request.Form. I also retrieved the chunks ID list, which is the block ID list from the Request.Form in a string format, split them as a list, then invoked the BlockBlob.PutBlockList method. After that our blob will be shown in the container and ready to be download. 1: [HttpPost] 2: public JsonResult Commit() 3: { 4: var error = string.Empty; 5: try 6: { 7: var name = Request.Form["name"]; 8: var list = Request.Form["list"]; 9: var ids = list 10: .Split(',') 11: .Where(id => !string.IsNullOrWhiteSpace(id)) 12: .Select(id => Convert.ToBase64String(BitConverter.GetBytes(int.Parse(id)))) 13: .ToArray(); 14:  15: var container = _client.GetContainerReference("test"); 16: container.CreateIfNotExists(); 17: var blob = container.GetBlockBlobReference(name); 18: blob.PutBlockList(ids); 19: } 20: catch (Exception e) 21: { 22: error = e.ToString(); 23: } 24:  25: return new JsonResult() 26: { 27: Data = new 28: { 29: success = string.IsNullOrWhiteSpace(error), 30: error = error 31: } 32: }; 33: } Now we finished all code we need. The whole process of uploading would be like this below. Below is the full client side JavaScript code. 1: <script type="text/javascript" src="~/Scripts/async.js"></script> 2: <script type="text/javascript"> 3: $(function () { 4: $("#upload_button_blob").click(function () { 5: // assert the browser support html5 6: if (window.File && window.Blob && window.FormData) { 7: alert("Your brwoser is awesome, let's rock!"); 8: } 9: else { 10: alert("Oh man plz update to a modern browser before try is cool stuff out."); 11: return; 12: } 13:  14: // start to upload each files in chunks 15: var files = $("#upload_files")[0].files; 16: for (var i = 0; i < files.length; i++) { 17: var file = files[i]; 18: var fileSize = file.size; 19: var fileName = file.name; 20:  21: // calculate the start and end byte index for each blocks(chunks) 22: // with the index, file name and index list for future using 23: var blockSizeInKB = $("#block_size").val(); 24: var blockSize = blockSizeInKB * 1024; 25: var blocks = []; 26: var offset = 0; 27: var index = 0; 28: var list = ""; 29: while (offset < fileSize) { 30: var start = offset; 31: var end = Math.min(offset + blockSize, fileSize); 32:  33: blocks.push({ 34: name: fileName, 35: index: index, 36: start: start, 37: end: end 38: }); 39: list += index + ","; 40:  41: offset = end; 42: index++; 43: } 44:  45: // define the function array and push all chunk upload operation into this array 46: var putBlocks = []; 47: blocks.forEach(function (block) { 48: putBlocks.push(function (callback) { 49: // load blob based on the start and end index for each chunks 50: var blob = file.slice(block.start, block.end); 51: // put the file name, index and blob into a temporary from 52: var fd = new FormData(); 53: fd.append("name", block.name); 54: fd.append("index", block.index); 55: fd.append("file", blob); 56: // post the form to backend service (asp.net mvc controller action) 57: $.ajax({ 58: url: "/Home/UploadInFormData", 59: data: fd, 60: processData: false, 61: contentType: "multipart/form-data", 62: type: "POST", 63: success: function (result) { 64: if (!result.success) { 65: alert(result.error); 66: } 67: callback(null, block.index); 68: } 69: }); 70: }); 71: }); 72:  73: // invoke the functions one by one 74: // then invoke the commit ajax call to put blocks into blob in azure storage 75: async.series(putBlocks, function (error, result) { 76: var data = { 77: name: fileName, 78: list: list 79: }; 80: $.post("/Home/Commit", data, function (result) { 81: if (!result.success) { 82: alert(result.error); 83: } 84: else { 85: alert("done!"); 86: } 87: }); 88: }); 89: } 90: }); 91: }); 92: </script> And below is the full ASP.NET MVC controller code. 1: public class HomeController : Controller 2: { 3: private CloudStorageAccount _account; 4: private CloudBlobClient _client; 5:  6: public HomeController() 7: : base() 8: { 9: _account = CloudStorageAccount.Parse(CloudConfigurationManager.GetSetting("DataConnectionString")); 10: _client = _account.CreateCloudBlobClient(); 11: } 12:  13: public ActionResult Index() 14: { 15: ViewBag.Message = "Modify this template to jump-start your ASP.NET MVC application."; 16:  17: return View(); 18: } 19:  20: [HttpPost] 21: public JsonResult UploadInFormData() 22: { 23: var error = string.Empty; 24: try 25: { 26: var name = Request.Form["name"]; 27: var index = int.Parse(Request.Form["index"]); 28: var file = Request.Files[0]; 29: var id = Convert.ToBase64String(BitConverter.GetBytes(index)); 30:  31: var container = _client.GetContainerReference("test"); 32: container.CreateIfNotExists(); 33: var blob = container.GetBlockBlobReference(name); 34: blob.PutBlock(id, file.InputStream, null); 35: } 36: catch (Exception e) 37: { 38: error = e.ToString(); 39: } 40:  41: return new JsonResult() 42: { 43: Data = new 44: { 45: success = string.IsNullOrWhiteSpace(error), 46: error = error 47: } 48: }; 49: } 50:  51: [HttpPost] 52: public JsonResult Commit() 53: { 54: var error = string.Empty; 55: try 56: { 57: var name = Request.Form["name"]; 58: var list = Request.Form["list"]; 59: var ids = list 60: .Split(',') 61: .Where(id => !string.IsNullOrWhiteSpace(id)) 62: .Select(id => Convert.ToBase64String(BitConverter.GetBytes(int.Parse(id)))) 63: .ToArray(); 64:  65: var container = _client.GetContainerReference("test"); 66: container.CreateIfNotExists(); 67: var blob = container.GetBlockBlobReference(name); 68: blob.PutBlockList(ids); 69: } 70: catch (Exception e) 71: { 72: error = e.ToString(); 73: } 74:  75: return new JsonResult() 76: { 77: Data = new 78: { 79: success = string.IsNullOrWhiteSpace(error), 80: error = error 81: } 82: }; 83: } 84: } And if we selected a file from the browser we will see our application will upload chunks in the size we specified to the server through ajax call in background, and then commit all chunks in one blob. Then we can find the blob in our Windows Azure Blob Storage.   Optimized by Parallel Upload In previous example we just uploaded our file in chunks. This solved the problem that ASP.NET MVC request content size limitation as well as the Windows Azure load balancer timeout. But it might introduce the performance problem since we uploaded chunks in sequence. In order to improve the upload performance we could modify our client side code a bit to make the upload operation invoked in parallel. The good news is that, “async.js” library provides the parallel execution function. If you remembered the code we invoke the service to upload chunks, it utilized “async.series” which means all functions will be executed in sequence. Now we will change this code to “async.parallel”. This will invoke all functions in parallel. 1: $("#upload_button_blob").click(function () { 2: // assert the browser support html5 3: ... ... 4: // start to upload each files in chunks 5: var files = $("#upload_files")[0].files; 6: for (var i = 0; i < files.length; i++) { 7: var file = files[i]; 8: var fileSize = file.size; 9: var fileName = file.name; 10: // calculate the start and end byte index for each blocks(chunks) 11: // with the index, file name and index list for future using 12: ... ... 13: // define the function array and push all chunk upload operation into this array 14: ... ... 15: // invoke the functions one by one 16: // then invoke the commit ajax call to put blocks into blob in azure storage 17: async.parallel(putBlocks, function (error, result) { 18: var data = { 19: name: fileName, 20: list: list 21: }; 22: $.post("/Home/Commit", data, function (result) { 23: if (!result.success) { 24: alert(result.error); 25: } 26: else { 27: alert("done!"); 28: } 29: }); 30: }); 31: } 32: }); In this way all chunks will be uploaded to the server side at the same time to maximize the bandwidth usage. This should work if the file was not very large and the chunk size was not very small. But for large file this might introduce another problem that too many ajax calls are sent to the server at the same time. So the best solution should be, upload the chunks in parallel with maximum concurrency limitation. The code below specified the concurrency limitation to 4, which means at the most only 4 ajax calls could be invoked at the same time. 1: $("#upload_button_blob").click(function () { 2: // assert the browser support html5 3: ... ... 4: // start to upload each files in chunks 5: var files = $("#upload_files")[0].files; 6: for (var i = 0; i < files.length; i++) { 7: var file = files[i]; 8: var fileSize = file.size; 9: var fileName = file.name; 10: // calculate the start and end byte index for each blocks(chunks) 11: // with the index, file name and index list for future using 12: ... ... 13: // define the function array and push all chunk upload operation into this array 14: ... ... 15: // invoke the functions one by one 16: // then invoke the commit ajax call to put blocks into blob in azure storage 17: async.parallelLimit(putBlocks, 4, function (error, result) { 18: var data = { 19: name: fileName, 20: list: list 21: }; 22: $.post("/Home/Commit", data, function (result) { 23: if (!result.success) { 24: alert(result.error); 25: } 26: else { 27: alert("done!"); 28: } 29: }); 30: }); 31: } 32: });   Summary In this post we discussed how to upload files in chunks to the backend service and then upload them into Windows Azure Blob Storage in blocks. We focused on the frontend side and leverage three new feature introduced in HTML 5 which are - File.slice: Read part of the file by specifying the start and end byte index. - Blob: File-like interface which contains the part of the file content. - FormData: Temporary form element that we can pass the chunk alone with some metadata to the backend service. Then we discussed the performance consideration of chunk uploading. Sequence upload cannot provide maximized upload speed, but the unlimited parallel upload might crash the browser and server if too many chunks. So we finally came up with the solution to upload chunks in parallel with the concurrency limitation. We also demonstrated how to utilize “async.js” JavaScript library to help us control the asynchronize call and the parallel limitation.   Regarding the chunk size and the parallel limitation value there is no “best” value. You need to test vary composition and find out the best one for your particular scenario. It depends on the local bandwidth, client machine cores and the server side (Windows Azure Cloud Service Virtual Machine) cores, memory and bandwidth. Below is one of my performance test result. The client machine was Windows 8 IE 10 with 4 cores. I was using Microsoft Cooperation Network. The web site was hosted on Windows Azure China North data center (in Beijing) with one small web role (1.7GB 1 core CPU, 1.75GB memory with 100Mbps bandwidth). The test cases were - Chunk size: 512KB, 1MB, 2MB, 4MB. - Upload Mode: Sequence, parallel (unlimited), parallel with limit (4 threads, 8 threads). - Chunk Format: base64 string, binaries. - Target file: 100MB. - Each case was tested 3 times. Below is the test result chart. Some thoughts, but not guidance or best practice: - Parallel gets better performance than series. - No significant performance improvement between parallel 4 threads and 8 threads. - Transform with binaries provides better performance than base64. - In all cases, chunk size in 1MB - 2MB gets better performance.   Hope this helps, Shaun All documents and related graphics, codes are provided "AS IS" without warranty of any kind. Copyright © Shaun Ziyan Xu. This work is licensed under the Creative Commons License.

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  • Ant get task throws "get doesn't support nested resources element" error

    - by David Corley
    The following ant xml should work according to documentation, but does not. Can anyone tell me if I'm doing something wrong. The get task should support the nested "resources" element in Ant 1.7.1 which is the version I'm using: -- <target name="setup"> <tstamp/> <!-- set up work areas --> <!--<taskdef name="ccmutil" classname="com.allfinanz.framework.tools.CCMUtil" classpath="\\Abate\Data\Build_Lib\Ivy\com.allfinanz\ccmutil\1.0\ccmutil-1.0.jar"/>--> <!-- 1st one is special, also sets ${project_wa} --> <!--<ccmutil file="${ant.file}" projects="framework, xpbuw, xpb, bil"/>--> <property name="framework_wa" value="../../../framework"/> <property name="xpbuw_wa" value="../../../xpbuw"/> <property name="xpb_wa" value="../../../xpb"/> <property name="bil_wa" value="../.."/> <!-- Create properties to hold the build values --> <property name="out" value="${user.dir}"/> <!-- This may be overridden from the command line --> <property name="locale" value="us"/> <!-- set contextRoot up as a property - this mean that it can be overwritten from the command line e.g.: ant -DcontextRoot=xpertBridge. --> <property name="contextRoot" value="xpertBridge"/> <property name="build_dir" value="${out}/${release}/build"/> <property name="distrib_dir" value="${out}/${release}/distrib"/> <property name="build.number" value="-1"/> <!-- Download dependencies from repo.fms.allfinanz.com--> <get dest="${lib}"> <resources> <url url="http://repo.fms.allfinanz.com/service/local/artifact/maven/redirect?r=central&amp;g=soap&amp;a=soap&amp;v=2.3.1&amp;e=jar"/> <url url="http://repo.fms.allfinanz.com/service/local/artifact/maven/redirect?r=JBOSS&amp;g=apache-fileupload&amp;a=commons-fileupload&amp;v=1.0&amp;e=jar"/> <url url="http://repo.fms.allfinanz.com/service/local/artifact/maven/redirect?r=thirdparty&amp;g=regexp&amp;a=regexp&amp;v=1.1&amp;e=jar"/> <url url="http://repo.fms.allfinanz.com/service/local/artifact/maven/redirect?r=thirdparty&amp;g=javax.mail&amp;a=mail&amp;v=1.2&amp;e=jar"/> <url url="http://repo.fms.allfinanz.com/service/local/artifact/maven/redirect?r=thirdparty&amp;g=com.ibm.ws.webservices&amp;a=webservices.thinclient&amp;v=6.1.0&amp;e=jar"/> <url url="http://repo.fms.allfinanz.com/service/local/artifact/maven/redirect?r=thirdparty&amp;g=avalon-framework&amp;a=avalon-framework&amp;v=4.2.0&amp;e=jar"/> <url url="http://repo.fms.allfinanz.com/service/local/artifact/maven/redirect?r=thirdparty&amp;g=jimi&amp;a=jimi&amp;v=1.0&amp;e=jar"/> <url url="http://repo.fms.allfinanz.com/service/local/artifact/maven/redirect?r=thirdparty&amp;g=batik&amp;a=batik-all&amp;v=1.6&amp;e=jar"/> <url url="http://repo.fms.allfinanz.com/service/local/artifact/maven/redirect?r=thirdparty&amp;g=bsf&amp;a=bsf&amp;v=2.3.0&amp;e=jar"/> <url url="http://repo.fms.allfinanz.com/service/local/artifact/maven/redirect?r=thirdparty&amp;g=rhino&amp;a=js&amp;v=1.5R3&amp;e=jar"/> <url url="http://repo.fms.allfinanz.com/service/local/artifact/maven/redirect?r=central&amp;g=commons-io&amp;a=commons-io&amp;v=1.1&amp;e=jar"/> <url url="http://repo.fms.allfinanz.com/service/local/artifact/maven/redirect?r=central&amp;g=commons-logging&amp;a=commons-logging&amp;v=1.0.4&amp;e=jar"/> <url url="http://repo.fms.allfinanz.com/service/local/artifact/maven/redirect?r=thirdparty&amp;g=xmlgraphics&amp;a=commons&amp;v=1.0&amp;e=jar"/> <url url="http://repo.fms.allfinanz.com/service/local/artifact/maven/redirect?r=thirdparty&amp;g=barcode4j&amp;a=barcode4j&amp;v=trunkBIL&amp;e=jar"/> <url url="http://repo.fms.allfinanz.com/service/local/artifact/maven/redirect?r=thirdparty&amp;g=com.ibm&amp;a=fmcojagt&amp;v=6.1&amp;e=jar"/> <url url="http://repo.fms.allfinanz.com/service/local/artifact/maven/redirect?r=thirdparty&amp;g=com.allfinanz&amp;a=ejbserversupport&amp;v=1.0&amp;e=jar"/> <url url="http://repo.fms.allfinanz.com/service/local/artifact/maven/redirect?r=thirdparty&amp;g=com.sun&amp;a=jce&amp;v=1.0&amp;e=zip"/> <url url="http://repo.fms.allfinanz.com/service/local/artifact/maven/redirect?r=thirdparty&amp;g=ssce&amp;a=ssce&amp;v=5.8&amp;e=jar"/> <url url="http://repo.fms.allfinanz.com/service/local/artifact/maven/redirect?r=thirdparty&amp;g=com.ibm&amp;a=mq&amp;v=5.1&amp;e=jar"/> <url url="http://repo.fms.allfinanz.com/service/local/artifact/maven/redirect?r=thirdparty&amp;g=com.ibm&amp;a=mqjms&amp;v=5.1&amp;e=jar"/> <url url="http://repo.fms.allfinanz.com/service/local/artifact/maven/redirect?r=thirdparty&amp;g=NetServerRemote&amp;a=NetServerRemote&amp;v=1.0&amp;e=jar"/> <url url="http://repo.fms.allfinanz.com/service/local/artifact/maven/redirect?r=thirdparty&amp;g=NetServerRMI&amp;a=NetServerRMI&amp;v=1.0&amp;e=jar"/> <url url="http://repo.fms.allfinanz.com/service/local/artifact/maven/redirect?r=thirdparty&amp;g=jwsdp&amp;a=saaj-api&amp;v=1.5&amp;e=jar&amp;c=api"/> <url url="http://repo.fms.allfinanz.com/service/local/artifact/maven/redirect?r=thirdparty&amp;g=jwsdp&amp;a=saaj-impl&amp;v=1.5&amp;e=jar&amp;c=impl"/> <url url="http://repo.fms.allfinanz.com/service/local/artifact/maven/redirect?r=thirdparty&amp;g=org.apache.xmlgraphics&amp;a=fop&amp;v=0.92b&amp;e=jar"/> <url url="http://repo.fms.allfinanz.com/service/local/artifact/maven/redirect?r=thirdparty&amp;g=xerces&amp;a=dom3-xml-apis&amp;v=1.0&amp;e=jar"/> <url url="http://repo.fms.allfinanz.com/service/local/artifact/maven/redirect?r=thirdparty&amp;g=org.apache&amp;a=derbynet&amp;v=10.0.2&amp;e=jar"/> <url url="http://repo.fms.allfinanz.com/service/local/artifact/maven/redirect?r=thirdparty&amp;g=com.sun&amp;a=jsse&amp;v=1.0&amp;e=jar"/> </resources> </get> </target>

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  • AngularJS on top of ASP.NET: Moving the MVC framework out to the browser

    - by Varun Chatterji
    Heavily drawing inspiration from Ruby on Rails, MVC4’s convention over configuration model of development soon became the Holy Grail of .NET web development. The MVC model brought with it the goodness of proper separation of concerns between business logic, data, and the presentation logic. However, the MVC paradigm, was still one in which server side .NET code could be mixed with presentation code. The Razor templating engine, though cleaner than its predecessors, still encouraged and allowed you to mix .NET server side code with presentation logic. Thus, for example, if the developer required a certain <div> tag to be shown if a particular variable ShowDiv was true in the View’s model, the code could look like the following: Fig 1: To show a div or not. Server side .NET code is used in the View Mixing .NET code with HTML in views can soon get very messy. Wouldn’t it be nice if the presentation layer (HTML) could be pure HTML? Also, in the ASP.NET MVC model, some of the business logic invariably resides in the controller. It is tempting to use an anti­pattern like the one shown above to control whether a div should be shown or not. However, best practice would indicate that the Controller should not be aware of the div. The ShowDiv variable in the model should not exist. A controller should ideally, only be used to do the plumbing of getting the data populated in the model and nothing else. The view (ideally pure HTML) should render the presentation layer based on the model. In this article we will see how Angular JS, a new JavaScript framework by Google can be used effectively to build web applications where: 1. Views are pure HTML 2. Controllers (in the server sense) are pure REST based API calls 3. The presentation layer is loaded as needed from partial HTML only files. What is MVVM? MVVM short for Model View View Model is a new paradigm in web development. In this paradigm, the Model and View stuff exists on the client side through javascript instead of being processed on the server through postbacks. These frameworks are JavaScript frameworks that facilitate the clear separation of the “frontend” or the data rendering logic from the “backend” which is typically just a REST based API that loads and processes data through a resource model. The frameworks are called MVVM as a change to the Model (through javascript) gets reflected in the view immediately i.e. Model > View. Also, a change on the view (through manual input) gets reflected in the model immediately i.e. View > Model. The following figure shows this conceptually (comments are shown in red): Fig 2: Demonstration of MVVM in action In Fig 2, two text boxes are bound to the same variable model.myInt. Thus, changing the view manually (changing one text box through keyboard input) also changes the other textbox in real time demonstrating V > M property of a MVVM framework. Furthermore, clicking the button adds 1 to the value of model.myInt thus changing the model through JavaScript. This immediately updates the view (the value in the two textboxes) thus demonstrating the M > V property of a MVVM framework. Thus we see that the model in a MVVM JavaScript framework can be regarded as “the single source of truth“. This is an important concept. Angular is one such MVVM framework. We shall use it to build a simple app that sends SMS messages to a particular number. Application, Routes, Views, Controllers, Scope and Models Angular can be used in many ways to construct web applications. For this article, we shall only focus on building Single Page Applications (SPAs). Many of the approaches we will follow in this article have alternatives. It is beyond the scope of this article to explain every nuance in detail but we shall try to touch upon the basic concepts and end up with a working application that can be used to send SMS messages using Sent.ly Plus (a service that is itself built using Angular). Before you read on, we would like to urge you to forget what you know about Models, Views, Controllers and Routes in the ASP.NET MVC4 framework. All these words have different meanings in the Angular world. Whenever these words are used in this article, they will refer to Angular concepts and not ASP.NET MVC4 concepts. The following figure shows the skeleton of the root page of an SPA: Fig 3: The skeleton of a SPA The skeleton of the application is based on the Bootstrap starter template which can be found at: http://getbootstrap.com/examples/starter­template/ Apart from loading the Angular, jQuery and Bootstrap JavaScript libraries, it also loads our custom scripts /app/js/controllers.js /app/js/app.js These scripts define the routes, views and controllers which we shall come to in a moment. Application Notice that the body tag (Fig. 3) has an extra attribute: ng­app=”smsApp” Providing this tag “bootstraps” our single page application. It tells Angular to load a “module” called smsApp. This “module” is defined /app/js/app.js angular.module('smsApp', ['smsApp.controllers', function () {}]) Fig 4: The definition of our application module The line shows above, declares a module called smsApp. It also declares that this module “depends” on another module called “smsApp.controllers”. The smsApp.controllers module will contain all the controllers for our SPA. Routing and Views Notice that in the Navbar (in Fig 3) we have included two hyperlinks to: “#/app” “#/help” This is how Angular handles routing. Since the URLs start with “#”, they are actually just bookmarks (and not server side resources). However, our route definition (in /app/js/app.js) gives these URLs a special meaning within the Angular framework. angular.module('smsApp', ['smsApp.controllers', function () { }]) //Configure the routes .config(['$routeProvider', function ($routeProvider) { $routeProvider.when('/binding', { templateUrl: '/app/partials/bindingexample.html', controller: 'BindingController' }); }]); Fig 5: The definition of a route with an associated partial view and controller As we can see from the previous code sample, we are using the $routeProvider object in the configuration of our smsApp module. Notice how the code “asks for” the $routeProvider object by specifying it as a dependency in the [] braces and then defining a function that accepts it as a parameter. This is known as dependency injection. Please refer to the following link if you want to delve into this topic: http://docs.angularjs.org/guide/di What the above code snippet is doing is that it is telling Angular that when the URL is “#/binding”, then it should load the HTML snippet (“partial view”) found at /app/partials/bindingexample.html. Also, for this URL, Angular should load the controller called “BindingController”. We have also marked the div with the class “container” (in Fig 3) with the ng­view attribute. This attribute tells Angular that views (partial HTML pages) defined in the routes will be loaded within this div. You can see that the Angular JavaScript framework, unlike many other frameworks, works purely by extending HTML tags and attributes. It also allows you to extend HTML with your own tags and attributes (through directives) if you so desire, you can find out more about directives at the following URL: http://www.codeproject.com/Articles/607873/Extending­HTML­with­AngularJS­Directives Controllers and Models We have seen how we define what views and controllers should be loaded for a particular route. Let us now consider how controllers are defined. Our controllers are defined in the file /app/js/controllers.js. The following snippet shows the definition of the “BindingController” which is loaded when we hit the URL http://localhost:port/index.html#/binding (as we have defined in the route earlier as shown in Fig 5). Remember that we had defined that our application module “smsApp” depends on the “smsApp.controllers” module (see Fig 4). The code snippet below shows how the “BindingController” defined in the route shown in Fig 5 is defined in the module smsApp.controllers: angular.module('smsApp.controllers', [function () { }]) .controller('BindingController', ['$scope', function ($scope) { $scope.model = {}; $scope.model.myInt = 6; $scope.addOne = function () { $scope.model.myInt++; } }]); Fig 6: The definition of a controller in the “smsApp.controllers” module. The pieces are falling in place! Remember Fig.2? That was the code of a partial view that was loaded within the container div of the skeleton SPA shown in Fig 3. The route definition shown in Fig 5 also defined that the controller called “BindingController” (shown in Fig 6.) was loaded when we loaded the URL: http://localhost:22544/index.html#/binding The button in Fig 2 was marked with the attribute ng­click=”addOne()” which added 1 to the value of model.myInt. In Fig 6, we can see that this function is actually defined in the “BindingController”. Scope We can see from Fig 6, that in the definition of “BindingController”, we defined a dependency on $scope and then, as usual, defined a function which “asks for” $scope as per the dependency injection pattern. So what is $scope? Any guesses? As you might have guessed a scope is a particular “address space” where variables and functions may be defined. This has a similar meaning to scope in a programming language like C#. Model: The Scope is not the Model It is tempting to assign variables in the scope directly. For example, we could have defined myInt as $scope.myInt = 6 in Fig 6 instead of $scope.model.myInt = 6. The reason why this is a bad idea is that scope in hierarchical in Angular. Thus if we were to define a controller which was defined within the another controller (nested controllers), then the inner controller would inherit the scope of the parent controller. This inheritance would follow JavaScript prototypal inheritance. Let’s say the parent controller defined a variable through $scope.myInt = 6. The child controller would inherit the scope through java prototypical inheritance. This basically means that the child scope has a variable myInt that points to the parent scopes myInt variable. Now if we assigned the value of myInt in the parent, the child scope would be updated with the same value as the child scope’s myInt variable points to the parent scope’s myInt variable. However, if we were to assign the value of the myInt variable in the child scope, then the link of that variable to the parent scope would be broken as the variable myInt in the child scope now points to the value 6 and not to the parent scope’s myInt variable. But, if we defined a variable model in the parent scope, then the child scope will also have a variable model that points to the model variable in the parent scope. Updating the value of $scope.model.myInt in the parent scope would change the model variable in the child scope too as the variable is pointed to the model variable in the parent scope. Now changing the value of $scope.model.myInt in the child scope would ALSO change the value in the parent scope. This is because the model reference in the child scope is pointed to the scope variable in the parent. We did no new assignment to the model variable in the child scope. We only changed an attribute of the model variable. Since the model variable (in the child scope) points to the model variable in the parent scope, we have successfully changed the value of myInt in the parent scope. Thus the value of $scope.model.myInt in the parent scope becomes the “single source of truth“. This is a tricky concept, thus it is considered good practice to NOT use scope inheritance. More info on prototypal inheritance in Angular can be found in the “JavaScript Prototypal Inheritance” section at the following URL: https://github.com/angular/angular.js/wiki/Understanding­Scopes. Building It: An Angular JS application using a .NET Web API Backend Now that we have a perspective on the basic components of an MVVM application built using Angular, let’s build something useful. We will build an application that can be used to send out SMS messages to a given phone number. The following diagram describes the architecture of the application we are going to build: Fig 7: Broad application architecture We are going to add an HTML Partial to our project. This partial will contain the form fields that will accept the phone number and message that needs to be sent as an SMS. It will also display all the messages that have previously been sent. All the executable code that is run on the occurrence of events (button clicks etc.) in the view resides in the controller. The controller interacts with the ASP.NET WebAPI to get a history of SMS messages, add a message etc. through a REST based API. For the purposes of simplicity, we will use an in memory data structure for the purposes of creating this application. Thus, the tasks ahead of us are: Creating the REST WebApi with GET, PUT, POST, DELETE methods. Creating the SmsView.html partial Creating the SmsController controller with methods that are called from the SmsView.html partial Add a new route that loads the controller and the partial. 1. Creating the REST WebAPI This is a simple task that should be quite straightforward to any .NET developer. The following listing shows our ApiController: public class SmsMessage { public string to { get; set; } public string message { get; set; } } public class SmsResource : SmsMessage { public int smsId { get; set; } } public class SmsResourceController : ApiController { public static Dictionary<int, SmsResource> messages = new Dictionary<int, SmsResource>(); public static int currentId = 0; // GET api/<controller> public List<SmsResource> Get() { List<SmsResource> result = new List<SmsResource>(); foreach (int key in messages.Keys) { result.Add(messages[key]); } return result; } // GET api/<controller>/5 public SmsResource Get(int id) { if (messages.ContainsKey(id)) return messages[id]; return null; } // POST api/<controller> public List<SmsResource> Post([FromBody] SmsMessage value) { //Synchronize on messages so we don't have id collisions lock (messages) { SmsResource res = (SmsResource) value; res.smsId = currentId++; messages.Add(res.smsId, res); //SentlyPlusSmsSender.SendMessage(value.to, value.message); return Get(); } } // PUT api/<controller>/5 public List<SmsResource> Put(int id, [FromBody] SmsMessage value) { //Synchronize on messages so we don't have id collisions lock (messages) { if (messages.ContainsKey(id)) { //Update the message messages[id].message = value.message; messages[id].to = value.message; } return Get(); } } // DELETE api/<controller>/5 public List<SmsResource> Delete(int id) { if (messages.ContainsKey(id)) { messages.Remove(id); } return Get(); } } Once this class is defined, we should be able to access the WebAPI by a simple GET request using the browser: http://localhost:port/api/SmsResource Notice the commented line: //SentlyPlusSmsSender.SendMessage The SentlyPlusSmsSender class is defined in the attached solution. We have shown this line as commented as we want to explain the core Angular concepts. If you load the attached solution, this line is uncommented in the source and an actual SMS will be sent! By default, the API returns XML. For consumption of the API in Angular, we would like it to return JSON. To change the default to JSON, we make the following change to WebApiConfig.cs file located in the App_Start folder. public static class WebApiConfig { public static void Register(HttpConfiguration config) { config.Routes.MapHttpRoute( name: "DefaultApi", routeTemplate: "api/{controller}/{id}", defaults: new { id = RouteParameter.Optional } ); var appXmlType = config.Formatters.XmlFormatter. SupportedMediaTypes. FirstOrDefault( t => t.MediaType == "application/xml"); config.Formatters.XmlFormatter.SupportedMediaTypes.Remove(appXmlType); } } We now have our backend REST Api which we can consume from Angular! 2. Creating the SmsView.html partial This simple partial will define two fields: the destination phone number (international format starting with a +) and the message. These fields will be bound to model.phoneNumber and model.message. We will also add a button that we shall hook up to sendMessage() in the controller. A list of all previously sent messages (bound to model.allMessages) will also be displayed below the form input. The following code shows the code for the partial: <!--­­ If model.errorMessage is defined, then render the error div -­­> <div class="alert alert-­danger alert-­dismissable" style="margin­-top: 30px;" ng­-show="model.errorMessage != undefined"> <button type="button" class="close" data­dismiss="alert" aria­hidden="true">&times;</button> <strong>Error!</strong> <br /> {{ model.errorMessage }} </div> <!--­­ The input fields bound to the model --­­> <div class="well" style="margin-­top: 30px;"> <table style="width: 100%;"> <tr> <td style="width: 45%; text-­align: center;"> <input type="text" placeholder="Phone number (eg; +44 7778 609466)" ng­-model="model.phoneNumber" class="form-­control" style="width: 90%" onkeypress="return checkPhoneInput();" /> </td> <td style="width: 45%; text-­align: center;"> <input type="text" placeholder="Message" ng­-model="model.message" class="form-­control" style="width: 90%" /> </td> <td style="text-­align: center;"> <button class="btn btn-­danger" ng-­click="sendMessage();" ng-­disabled="model.isAjaxInProgress" style="margin­right: 5px;">Send</button> <img src="/Content/ajax-­loader.gif" ng­-show="model.isAjaxInProgress" /> </td> </tr> </table> </div> <!--­­ The past messages ­­--> <div style="margin-­top: 30px;"> <!­­-- The following div is shown if there are no past messages --­­> <div ng­-show="model.allMessages.length == 0"> No messages have been sent yet! </div> <!--­­ The following div is shown if there are some past messages --­­> <div ng-­show="model.allMessages.length == 0"> <table style="width: 100%;" class="table table-­striped"> <tr> <td>Phone Number</td> <td>Message</td> <td></td> </tr> <!--­­ The ng-­repeat directive is line the repeater control in .NET, but as you can see this partial is pure HTML which is much cleaner --> <tr ng-­repeat="message in model.allMessages"> <td>{{ message.to }}</td> <td>{{ message.message }}</td> <td> <button class="btn btn-­danger" ng-­click="delete(message.smsId);" ng­-disabled="model.isAjaxInProgress">Delete</button> </td> </tr> </table> </div> </div> The above code is commented and should be self explanatory. Conditional rendering is achieved through using the ng-­show=”condition” attribute on various div tags. Input fields are bound to the model and the send button is bound to the sendMessage() function in the controller as through the ng­click=”sendMessage()” attribute defined on the button tag. While AJAX calls are taking place, the controller sets model.isAjaxInProgress to true. Based on this variable, buttons are disabled through the ng-­disabled directive which is added as an attribute to the buttons. The ng-­repeat directive added as an attribute to the tr tag causes the table row to be rendered multiple times much like an ASP.NET repeater. 3. Creating the SmsController controller The penultimate piece of our application is the controller which responds to events from our view and interacts with our MVC4 REST WebAPI. The following listing shows the code we need to add to /app/js/controllers.js. Note that controller definitions can be chained. Also note that this controller “asks for” the $http service. The $http service is a simple way in Angular to do AJAX. So far we have only encountered modules, controllers, views and directives in Angular. The $http is new entity in Angular called a service. More information on Angular services can be found at the following URL: http://docs.angularjs.org/guide/dev_guide.services.understanding_services. .controller('SmsController', ['$scope', '$http', function ($scope, $http) { //We define the model $scope.model = {}; //We define the allMessages array in the model //that will contain all the messages sent so far $scope.model.allMessages = []; //The error if any $scope.model.errorMessage = undefined; //We initially load data so set the isAjaxInProgress = true; $scope.model.isAjaxInProgress = true; //Load all the messages $http({ url: '/api/smsresource', method: "GET" }). success(function (data, status, headers, config) { this callback will be called asynchronously //when the response is available $scope.model.allMessages = data; //We are done with AJAX loading $scope.model.isAjaxInProgress = false; }). error(function (data, status, headers, config) { //called asynchronously if an error occurs //or server returns response with an error status. $scope.model.errorMessage = "Error occurred status:" + status; //We are done with AJAX loading $scope.model.isAjaxInProgress = false; }); $scope.delete = function (id) { //We are making an ajax call so we set this to true $scope.model.isAjaxInProgress = true; $http({ url: '/api/smsresource/' + id, method: "DELETE" }). success(function (data, status, headers, config) { // this callback will be called asynchronously // when the response is available $scope.model.allMessages = data; //We are done with AJAX loading $scope.model.isAjaxInProgress = false; }); error(function (data, status, headers, config) { // called asynchronously if an error occurs // or server returns response with an error status. $scope.model.errorMessage = "Error occurred status:" + status; //We are done with AJAX loading $scope.model.isAjaxInProgress = false; }); } $scope.sendMessage = function () { $scope.model.errorMessage = undefined; var message = ''; if($scope.model.message != undefined) message = $scope.model.message.trim(); if ($scope.model.phoneNumber == undefined || $scope.model.phoneNumber == '' || $scope.model.phoneNumber.length < 10 || $scope.model.phoneNumber[0] != '+') { $scope.model.errorMessage = "You must enter a valid phone number in international format. Eg: +44 7778 609466"; return; } if (message.length == 0) { $scope.model.errorMessage = "You must specify a message!"; return; } //We are making an ajax call so we set this to true $scope.model.isAjaxInProgress = true; $http({ url: '/api/smsresource', method: "POST", data: { to: $scope.model.phoneNumber, message: $scope.model.message } }). success(function (data, status, headers, config) { // this callback will be called asynchronously // when the response is available $scope.model.allMessages = data; //We are done with AJAX loading $scope.model.isAjaxInProgress = false; }). error(function (data, status, headers, config) { // called asynchronously if an error occurs // or server returns response with an error status. $scope.model.errorMessage = "Error occurred status:" + status // We are done with AJAX loading $scope.model.isAjaxInProgress = false; }); } }]); We can see from the previous listing how the functions that are called from the view are defined in the controller. It should also be evident how easy it is to make AJAX calls to consume our MVC4 REST WebAPI. Now we are left with the final piece. We need to define a route that associates a particular path with the view we have defined and the controller we have defined. 4. Add a new route that loads the controller and the partial This is the easiest part of the puzzle. We simply define another route in the /app/js/app.js file: $routeProvider.when('/sms', { templateUrl: '/app/partials/smsview.html', controller: 'SmsController' }); Conclusion In this article we have seen how much of the server side functionality in the MVC4 framework can be moved to the browser thus delivering a snappy and fast user interface. We have seen how we can build client side HTML only views that avoid the messy syntax offered by server side Razor views. We have built a functioning app from the ground up. The significant advantage of this approach to building web apps is that the front end can be completely platform independent. Even though we used ASP.NET to create our REST API, we could just easily have used any other language such as Node.js, Ruby etc without changing a single line of our front end code. Angular is a rich framework and we have only touched on basic functionality required to create a SPA. For readers who wish to delve further into the Angular framework, we would recommend the following URL as a starting point: http://docs.angularjs.org/misc/started. To get started with the code for this project: Sign up for an account at http://plus.sent.ly (free) Add your phone number Go to the “My Identies Page” Note Down your Sender ID, Consumer Key and Consumer Secret Download the code for this article at: https://docs.google.com/file/d/0BzjEWqSE31yoZjZlV0d0R2Y3eW8/edit?usp=sharing Change the values of Sender Id, Consumer Key and Consumer Secret in the web.config file Run the project through Visual Studio!

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  • Silverlight for Windows Embedded tutorial (step 4)

    - by Valter Minute
    I’m back with my Silverlight for Windows Embedded tutorial. Sorry for the long delay between step 3 and step 4, the MVP summit and some work related issue prevented me from working on the tutorial during the last weeks. In our first,  second and third tutorial steps we implemented some very simple applications, just to understand the basic structure of a Silverlight for Windows Embedded application, learn how to handle events and how to operate on images. In this third step our sample application will be slightly more complicated, to introduce two new topics: list boxes and custom control. We will also learn how to create controls at runtime. I choose to explain those topics together and provide a sample a bit more complicated than usual just to start to give the feeling of how a “real” Silverlight for Windows Embedded application is organized. As usual we can start using Expression Blend to define our main page. In this case we will have a listbox and a textblock. Here’s the XAML code: <UserControl xmlns="http://schemas.microsoft.com/winfx/2006/xaml/presentation" xmlns:x="http://schemas.microsoft.com/winfx/2006/xaml" x:Class="ListDemo.Page" Width="640" Height="480" x:Name="ListPage" xmlns:ListDemo="clr-namespace:ListDemo">   <Grid x:Name="LayoutRoot" Background="White"> <ListBox Margin="19,57,19,66" x:Name="FileList" SelectionChanged="Filelist_SelectionChanged"/> <TextBlock Height="35" Margin="19,8,19,0" VerticalAlignment="Top" TextWrapping="Wrap" x:Name="CurrentDir" Text="TextBlock" FontSize="20"/> </Grid> </UserControl> In our listbox we will load a list of directories, starting from the filesystem root (there are no drives in Windows CE, the filesystem has a single root named “\”). When the user clicks on an item inside the list, the corresponding directory path will be displayed in the TextBlock object and the subdirectories of the selected branch will be shown inside the list. As you can see we declared an event handler for the SelectionChanged event of our listbox. We also used a different font size for the TextBlock, to make it more readable. XAML and Expression Blend allow you to customize your UI pretty heavily, experiment with the tools and discover how you can completely change the aspect of your application without changing a single line of code! Inside our ListBox we want to insert the directory presenting a nice icon and their name, just like you are used to see them inside Windows 7 file explorer, for example. To get this we will define a user control. This is a custom object that will behave like “regular” Silverlight for Windows Embedded objects inside our application. First of all we have to define the look of our custom control, named DirectoryItem, using XAML: <UserControl xmlns="http://schemas.microsoft.com/winfx/2006/xaml/presentation" xmlns:x="http://schemas.microsoft.com/winfx/2006/xaml" xmlns:d="http://schemas.microsoft.com/expression/blend/2008" xmlns:mc="http://schemas.openxmlformats.org/markup-compatibility/2006" mc:Ignorable="d" x:Class="ListDemo.DirectoryItem" Width="500" Height="80">   <StackPanel x:Name="LayoutRoot" Orientation="Horizontal"> <Canvas Width="31.6667" Height="45.9583" Margin="10,10,10,10" RenderTransformOrigin="0.5,0.5"> <Canvas.RenderTransform> <TransformGroup> <ScaleTransform/> <SkewTransform/> <RotateTransform Angle="-31.27"/> <TranslateTransform/> </TransformGroup> </Canvas.RenderTransform> <Rectangle Width="31.6667" Height="45.8414" Canvas.Left="0" Canvas.Top="0.116943" Stretch="Fill"> <Rectangle.Fill> <LinearGradientBrush StartPoint="0.142631,0.75344" EndPoint="1.01886,0.75344"> <LinearGradientBrush.RelativeTransform> <TransformGroup> <SkewTransform CenterX="0.142631" CenterY="0.75344" AngleX="19.3128" AngleY="0"/> <RotateTransform CenterX="0.142631" CenterY="0.75344" Angle="-35.3436"/> </TransformGroup> </LinearGradientBrush.RelativeTransform> <LinearGradientBrush.GradientStops> <GradientStop Color="#FF7B6802" Offset="0"/> <GradientStop Color="#FFF3D42C" Offset="1"/> </LinearGradientBrush.GradientStops> </LinearGradientBrush> </Rectangle.Fill> </Rectangle> <Rectangle Width="29.8441" Height="43.1517" Canvas.Left="0.569519" Canvas.Top="1.05249" Stretch="Fill"> <Rectangle.Fill> <LinearGradientBrush StartPoint="0.142632,0.753441" EndPoint="1.01886,0.753441"> <LinearGradientBrush.RelativeTransform> <TransformGroup> <SkewTransform CenterX="0.142632" CenterY="0.753441" AngleX="19.3127" AngleY="0"/> <RotateTransform CenterX="0.142632" CenterY="0.753441" Angle="-35.3437"/> </TransformGroup> </LinearGradientBrush.RelativeTransform> <LinearGradientBrush.GradientStops> <GradientStop Color="#FFCDCDCD" Offset="0.0833333"/> <GradientStop Color="#FFFFFFFF" Offset="1"/> </LinearGradientBrush.GradientStops> </LinearGradientBrush> </Rectangle.Fill> </Rectangle> <Rectangle Width="29.8441" Height="43.1517" Canvas.Left="0.455627" Canvas.Top="2.28036" Stretch="Fill"> <Rectangle.Fill> <LinearGradientBrush StartPoint="0.142631,0.75344" EndPoint="1.01886,0.75344"> <LinearGradientBrush.RelativeTransform> <TransformGroup> <SkewTransform CenterX="0.142631" CenterY="0.75344" AngleX="19.3128" AngleY="0"/> <RotateTransform CenterX="0.142631" CenterY="0.75344" Angle="-35.3436"/> </TransformGroup> </LinearGradientBrush.RelativeTransform> <LinearGradientBrush.GradientStops> <GradientStop Color="#FFCDCDCD" Offset="0.0833333"/> <GradientStop Color="#FFFFFFFF" Offset="1"/> </LinearGradientBrush.GradientStops> </LinearGradientBrush> </Rectangle.Fill> </Rectangle> <Rectangle Width="29.8441" Height="43.1517" Canvas.Left="0.455627" Canvas.Top="1.34485" Stretch="Fill"> <Rectangle.Fill> <LinearGradientBrush StartPoint="0.142631,0.75344" EndPoint="1.01886,0.75344"> <LinearGradientBrush.RelativeTransform> <TransformGroup> <SkewTransform CenterX="0.142631" CenterY="0.75344" AngleX="19.3128" AngleY="0"/> <RotateTransform CenterX="0.142631" CenterY="0.75344" Angle="-35.3436"/> </TransformGroup> </LinearGradientBrush.RelativeTransform> <LinearGradientBrush.GradientStops> <GradientStop Color="#FFCDCDCD" Offset="0.0833333"/> <GradientStop Color="#FFFFFFFF" Offset="1"/> </LinearGradientBrush.GradientStops> </LinearGradientBrush> </Rectangle.Fill> </Rectangle> <Rectangle Width="26.4269" Height="45.8414" Canvas.Left="0.227798" Canvas.Top="0" Stretch="Fill"> <Rectangle.Fill> <LinearGradientBrush StartPoint="0.142631,0.75344" EndPoint="1.01886,0.75344"> <LinearGradientBrush.RelativeTransform> <TransformGroup> <SkewTransform CenterX="0.142631" CenterY="0.75344" AngleX="19.3127" AngleY="0"/> <RotateTransform CenterX="0.142631" CenterY="0.75344" Angle="-35.3436"/> </TransformGroup> </LinearGradientBrush.RelativeTransform> <LinearGradientBrush.GradientStops> <GradientStop Color="#FF7B6802" Offset="0"/> <GradientStop Color="#FFF3D42C" Offset="1"/> </LinearGradientBrush.GradientStops> </LinearGradientBrush> </Rectangle.Fill> </Rectangle> <Rectangle Width="1.25301" Height="45.8414" Canvas.Left="1.70862" Canvas.Top="0.116943" Stretch="Fill" Fill="#FFEBFF07"/> </Canvas> <TextBlock Height="80" x:Name="Name" Width="448" TextWrapping="Wrap" VerticalAlignment="Center" FontSize="24" Text="Directory"/> </StackPanel> </UserControl> As you can see, this XAML contains many graphic elements. Those elements are used to design the folder icon. The original drawing has been designed in Expression Design and then exported as XAML. In Silverlight for Windows Embedded you can use vector images. This means that your images will look good even when scaled or rotated. In our DirectoryItem custom control we have a TextBlock named Name, that will be used to display….(suspense)…. the directory name (I’m too lazy to invent fancy names for controls, and using “boring” intuitive names will make code more readable, I hope!). Now that we have some XAML code, we may execute XAML2CPP to generate part of the aplication code for us. We should then add references to our XAML2CPP generated resource file and include in our code and add a reference to the XAML runtime library to our sources file (you can follow the instruction of the first tutorial step to do that), To generate the code used in this tutorial you need XAML2CPP ver 1.0.1.0, that is downloadable here: http://geekswithblogs.net/WindowsEmbeddedCookbook/archive/2010/03/08/xaml2cpp-1.0.1.0.aspx We can now create our usual simple Win32 application inside Platform Builder, using the same step described in the first chapter of this tutorial (http://geekswithblogs.net/WindowsEmbeddedCookbook/archive/2009/10/01/silverlight-for-embedded-tutorial.aspx). We can declare a class for our main page, deriving it from the template that XAML2CPP generated for us: class ListPage : public TListPage<ListPage> { ... } We will see the ListPage class code in a short time, but before we will see the code of our DirectoryItem user control. This object will be used to populate our list, one item for each directory. To declare a user control things are a bit more complicated (but also in this case XAML2CPP will write most of the “boilerplate” code for use. To interact with a user control you should declare an interface. An interface defines the functions of a user control that can be called inside the application code. Our custom control is currently quite simple and we just need some member functions to store and retrieve a full pathname inside our control. The control will display just the last part of the path inside the control. An interface is declared as a C++ class that has only abstract virtual members. It should also have an UUID associated with it. UUID means Universal Unique IDentifier and it’s a 128 bit number that will identify our interface without the need of specifying its fully qualified name. UUIDs are used to identify COM interfaces and, as we discovered in chapter one, Silverlight for Windows Embedded is based on COM or, at least, provides a COM-like Application Programming Interface (API). Here’s the declaration of the DirectoryItem interface: class __declspec(novtable,uuid("{D38C66E5-2725-4111-B422-D75B32AA8702}")) IDirectoryItem : public IXRCustomUserControl { public:   virtual HRESULT SetFullPath(BSTR fullpath) = 0; virtual HRESULT GetFullPath(BSTR* retval) = 0; }; The interface is derived from IXRCustomControl, this will allow us to add our object to a XAML tree. It declares the two functions needed to set and get the full path, but don’t implement them. Implementation will be done inside the control class. The interface only defines the functions of our control class that are accessible from the outside. It’s a sort of “contract” between our control and the applications that will use it. We must support what’s inside the contract and the application code should know nothing else about our own control. To reference our interface we will use the UUID, to make code more readable we can declare a #define in this way: #define IID_IDirectoryItem __uuidof(IDirectoryItem) Silverlight for Windows Embedded objects (like COM objects) use a reference counting mechanism to handle object destruction. Every time you store a pointer to an object you should call its AddRef function and every time you no longer need that pointer you should call Release. The object keeps an internal counter, incremented for each AddRef and decremented on Release. When the counter reaches 0, the object is destroyed. Managing reference counting in our code can be quite complicated and, since we are lazy (I am, at least!), we will use a great feature of Silverlight for Windows Embedded: smart pointers.A smart pointer can be connected to a Silverlight for Windows Embedded object and manages its reference counting. To declare a smart pointer we must use the XRPtr template: typedef XRPtr<IDirectoryItem> IDirectoryItemPtr; Now that we have defined our interface, it’s time to implement our user control class. XAML2CPP has implemented a class for us, and we have only to derive our class from it, defining the main class and interface of our new custom control: class DirectoryItem : public DirectoryItemUserControlRegister<DirectoryItem,IDirectoryItem> { ... } XAML2CPP has generated some code for us to support the user control, we don’t have to mind too much about that code, since it will be generated (or written by hand, if you like) always in the same way, for every user control. But knowing how does this works “under the hood” is still useful to understand the architecture of Silverlight for Windows Embedded. Our base class declaration is a bit more complex than the one we used for a simple page in the previous chapters: template <class A,class B> class DirectoryItemUserControlRegister : public XRCustomUserControlImpl<A,B>,public TDirectoryItem<A,XAML2CPPUserControl> { ... } This class derives from the XAML2CPP generated template class, like the ListPage class, but it uses XAML2CPPUserControl for the implementation of some features. This class shares the same ancestor of XAML2CPPPage (base class for “regular” XAML pages), XAML2CPPBase, implements binding of member variables and event handlers but, instead of loading and creating its own XAML tree, it attaches to an existing one. The XAML tree (and UI) of our custom control is created and loaded by the XRCustomUserControlImpl class. This class is part of the Silverlight for Windows Embedded framework and implements most of the functions needed to build-up a custom control in Silverlight (the guys that developed Silverlight for Windows Embedded seem to care about lazy programmers!). We have just to initialize it, providing our class (DirectoryItem) and interface (IDirectoryItem). Our user control class has also a static member: protected:   static HINSTANCE hInstance; This is used to store the HINSTANCE of the modules that contain our user control class. I don’t like this implementation, but I can’t find a better one, so if somebody has good ideas about how to handle the HINSTANCE object, I’ll be happy to hear suggestions! It also implements two static members required by XRCustomUserControlImpl. The first one is used to load the XAML UI of our custom control: static HRESULT GetXamlSource(XRXamlSource* pXamlSource) { pXamlSource->SetResource(hInstance,TEXT("XAML"),IDR_XAML_DirectoryItem); return S_OK; }   It initializes a XRXamlSource object, connecting it to the XAML resource that XAML2CPP has included in our resource script. The other method is used to register our custom control, allowing Silverlight for Windows Embedded to create it when it load some XAML or when an application creates a new control at runtime (more about this later): static HRESULT Register() { return XRCustomUserControlImpl<A,B>::Register(__uuidof(B), L"DirectoryItem", L"clr-namespace:DirectoryItemNamespace"); } To register our control we should provide its interface UUID, the name of the corresponding element in the XAML tree and its current namespace (namespaces compatible with Silverlight must use the “clr-namespace” prefix. We may also register additional properties for our objects, allowing them to be loaded and saved inside XAML. In this case we have no permanent properties and the Register method will just register our control. An additional static method is implemented to allow easy registration of our custom control inside our application WinMain function: static HRESULT RegisterUserControl(HINSTANCE hInstance) { DirectoryItemUserControlRegister::hInstance=hInstance; return DirectoryItemUserControlRegister<A,B>::Register(); } Now our control is registered and we will be able to create it using the Silverlight for Windows Embedded runtime functions. But we need to bind our members and event handlers to have them available like we are used to do for other XAML2CPP generated objects. To bind events and members we need to implement the On_Loaded function: virtual HRESULT OnLoaded(__in IXRDependencyObject* pRoot) { HRESULT retcode; IXRApplicationPtr app; if (FAILED(retcode=GetXRApplicationInstance(&app))) return retcode; return ((A*)this)->Init(pRoot,hInstance,app); } This function will call the XAML2CPPUserControl::Init member that will connect the “root” member with the XAML sub tree that has been created for our control and then calls BindObjects and BindEvents to bind members and events to our code. Now we can go back to our application code (the code that you’ll have to actually write) to see the contents of our DirectoryItem class: class DirectoryItem : public DirectoryItemUserControlRegister<DirectoryItem,IDirectoryItem> { protected:   WCHAR fullpath[_MAX_PATH+1];   public:   DirectoryItem() { *fullpath=0; }   virtual HRESULT SetFullPath(BSTR fullpath) { wcscpy_s(this->fullpath,fullpath);   WCHAR* p=fullpath;   for(WCHAR*q=wcsstr(p,L"\\");q;p=q+1,q=wcsstr(p,L"\\")) ;   Name->SetText(p); return S_OK; }   virtual HRESULT GetFullPath(BSTR* retval) { *retval=SysAllocString(fullpath); return S_OK; } }; It’s pretty easy and contains a fullpath member (used to store that path of the directory connected with the user control) and the implementation of the two interface members that can be used to set and retrieve the path. The SetFullPath member parses the full path and displays just the last branch directory name inside the “Name” TextBlock object. As you can see, implementing a user control in Silverlight for Windows Embedded is not too complex and using XAML also for the UI of the control allows us to re-use the same mechanisms that we learnt and used in the previous steps of our tutorial. Now let’s see how the main page is managed by the ListPage class. class ListPage : public TListPage<ListPage> { protected:   // current path TCHAR curpath[_MAX_PATH+1]; It has a member named “curpath” that is used to store the current directory. It’s initialized inside the constructor: ListPage() { *curpath=0; } And it’s value is displayed inside the “CurrentDir” TextBlock inside the initialization function: virtual HRESULT Init(HINSTANCE hInstance,IXRApplication* app) { HRESULT retcode;   if (FAILED(retcode=TListPage<ListPage>::Init(hInstance,app))) return retcode;   CurrentDir->SetText(L"\\"); return S_OK; } The FillFileList function is used to enumerate subdirectories of the current dir and add entries for each one inside the list box that fills most of the client area of our main page: HRESULT FillFileList() { HRESULT retcode; IXRItemCollectionPtr items; IXRApplicationPtr app;   if (FAILED(retcode=GetXRApplicationInstance(&app))) return retcode; // retrieves the items contained in the listbox if (FAILED(retcode=FileList->GetItems(&items))) return retcode;   // clears the list if (FAILED(retcode=items->Clear())) return retcode;   // enumerates files and directory in the current path WCHAR filemask[_MAX_PATH+1];   wcscpy_s(filemask,curpath); wcscat_s(filemask,L"\\*.*");   WIN32_FIND_DATA finddata; HANDLE findhandle;   findhandle=FindFirstFile(filemask,&finddata);   // the directory is empty? if (findhandle==INVALID_HANDLE_VALUE) return S_OK;   do { if (finddata.dwFileAttributes&=FILE_ATTRIBUTE_DIRECTORY) { IXRListBoxItemPtr listboxitem;   // add a new item to the listbox if (FAILED(retcode=app->CreateObject(IID_IXRListBoxItem,&listboxitem))) { FindClose(findhandle); return retcode; }   if (FAILED(retcode=items->Add(listboxitem,NULL))) { FindClose(findhandle); return retcode; }   IDirectoryItemPtr directoryitem;   if (FAILED(retcode=app->CreateObject(IID_IDirectoryItem,&directoryitem))) { FindClose(findhandle); return retcode; }   WCHAR fullpath[_MAX_PATH+1];   wcscpy_s(fullpath,curpath); wcscat_s(fullpath,L"\\"); wcscat_s(fullpath,finddata.cFileName);   if (FAILED(retcode=directoryitem->SetFullPath(fullpath))) { FindClose(findhandle); return retcode; }   XAML2CPPXRValue value((IXRDependencyObject*)directoryitem);   if (FAILED(retcode=listboxitem->SetContent(&value))) { FindClose(findhandle); return retcode; } } } while (FindNextFile(findhandle,&finddata));   FindClose(findhandle); return S_OK; } This functions retrieve a pointer to the collection of the items contained in the directory listbox. The IXRItemCollection interface is used by listboxes and comboboxes and allow you to clear the list (using Clear(), as our function does at the beginning) and change its contents by adding and removing elements. This function uses the FindFirstFile/FindNextFile functions to enumerate all the objects inside our current directory and for each subdirectory creates a IXRListBoxItem object. You can insert any kind of control inside a list box, you don’t need a IXRListBoxItem, but using it will allow you to handle the selected state of an item, highlighting it inside the list. The function creates a list box item using the CreateObject function of XRApplication. The same function is then used to create an instance of our custom control. The function returns a pointer to the control IDirectoryItem interface and we can use it to store the directory full path inside the object and add it as content of the IXRListBox item object, adding it to the listbox contents. The listbox generates an event (SelectionChanged) each time the user clicks on one of the items contained in the listbox. We implement an event handler for that event and use it to change our current directory and repopulate the listbox. The current directory full path will be displayed in the TextBlock: HRESULT Filelist_SelectionChanged(IXRDependencyObject* source,XRSelectionChangedEventArgs* args) { HRESULT retcode;   IXRListBoxItemPtr listboxitem;   if (!args->pAddedItem) return S_OK;   if (FAILED(retcode=args->pAddedItem->QueryInterface(IID_IXRListBoxItem,(void**)&listboxitem))) return retcode;   XRValue content; if (FAILED(retcode=listboxitem->GetContent(&content))) return retcode;   if (content.vType!=VTYPE_OBJECT) return E_FAIL;   IDirectoryItemPtr directoryitem;   if (FAILED(retcode=content.pObjectVal->QueryInterface(IID_IDirectoryItem,(void**)&directoryitem))) return retcode;   content.pObjectVal->Release(); content.pObjectVal=NULL;   BSTR fullpath=NULL;   if (FAILED(retcode=directoryitem->GetFullPath(&fullpath))) return retcode;   CurrentDir->SetText(fullpath);   wcscpy_s(curpath,fullpath); FillFileList(); SysFreeString(fullpath);     return S_OK; } }; The function uses the pAddedItem member of the XRSelectionChangedEventArgs object to retrieve the currently selected item, converts it to a IXRListBoxItem interface using QueryInterface, and then retrives its contents (IDirectoryItem object). Using the GetFullPath method we can get the full path of our selected directory and assing it to the curdir member. A call to FillFileList will update the listbox contents, displaying the list of subdirectories of the selected folder. To build our sample we just need to add code to our WinMain function: int WINAPI WinMain(HINSTANCE hInstance, HINSTANCE hPrevInstance, LPTSTR lpCmdLine, int nCmdShow) { if (!XamlRuntimeInitialize()) return -1;   HRESULT retcode;   IXRApplicationPtr app; if (FAILED(retcode=GetXRApplicationInstance(&app))) return -1;   if (FAILED(retcode=DirectoryItem::RegisterUserControl(hInstance))) return retcode;   ListPage page;   if (FAILED(page.Init(hInstance,app))) return -1;   page.FillFileList();   UINT exitcode;   if (FAILED(page.GetVisualHost()->StartDialog(&exitcode))) return -1;   return 0; } This code is very similar to the one of the WinMains of our previous samples. The main differences are that we register our custom control (you should do that as soon as you have initialized the XAML runtime) and call FillFileList after the initialization of our ListPage object to load the contents of the root folder of our device inside the listbox. As usual you can download the full sample source code from here: http://cid-9b7b0aefe3514dc5.skydrive.live.com/self.aspx/.Public/ListBoxTest.zip

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  • An Xml Serializable PropertyBag Dictionary Class for .NET

    - by Rick Strahl
    I don't know about you but I frequently need property bags in my applications to store and possibly cache arbitrary data. Dictionary<T,V> works well for this although I always seem to be hunting for a more specific generic type that provides a string key based dictionary. There's string dictionary, but it only works with strings. There's Hashset<T> but it uses the actual values as keys. In most key value pair situations for me string is key value to work off. Dictionary<T,V> works well enough, but there are some issues with serialization of dictionaries in .NET. The .NET framework doesn't do well serializing IDictionary objects out of the box. The XmlSerializer doesn't support serialization of IDictionary via it's default serialization, and while the DataContractSerializer does support IDictionary serialization it produces some pretty atrocious XML. What doesn't work? First off Dictionary serialization with the Xml Serializer doesn't work so the following fails: [TestMethod] public void DictionaryXmlSerializerTest() { var bag = new Dictionary<string, object>(); bag.Add("key", "Value"); bag.Add("Key2", 100.10M); bag.Add("Key3", Guid.NewGuid()); bag.Add("Key4", DateTime.Now); bag.Add("Key5", true); bag.Add("Key7", new byte[3] { 42, 45, 66 }); TestContext.WriteLine(this.ToXml(bag)); } public string ToXml(object obj) { if (obj == null) return null; StringWriter sw = new StringWriter(); XmlSerializer ser = new XmlSerializer(obj.GetType()); ser.Serialize(sw, obj); return sw.ToString(); } The error you get with this is: System.NotSupportedException: The type System.Collections.Generic.Dictionary`2[[System.String, mscorlib, Version=4.0.0.0, Culture=neutral, PublicKeyToken=b77a5c561934e089],[System.Object, mscorlib, Version=4.0.0.0, Culture=neutral, PublicKeyToken=b77a5c561934e089]] is not supported because it implements IDictionary. Got it! BTW, the same is true with binary serialization. Running the same code above against the DataContractSerializer does work: [TestMethod] public void DictionaryDataContextSerializerTest() { var bag = new Dictionary<string, object>(); bag.Add("key", "Value"); bag.Add("Key2", 100.10M); bag.Add("Key3", Guid.NewGuid()); bag.Add("Key4", DateTime.Now); bag.Add("Key5", true); bag.Add("Key7", new byte[3] { 42, 45, 66 }); TestContext.WriteLine(this.ToXmlDcs(bag)); } public string ToXmlDcs(object value, bool throwExceptions = false) { var ser = new DataContractSerializer(value.GetType(), null, int.MaxValue, true, false, null); MemoryStream ms = new MemoryStream(); ser.WriteObject(ms, value); return Encoding.UTF8.GetString(ms.ToArray(), 0, (int)ms.Length); } This DOES work but produces some pretty heinous XML (formatted with line breaks and indentation here): <ArrayOfKeyValueOfstringanyType xmlns="http://schemas.microsoft.com/2003/10/Serialization/Arrays" xmlns:i="http://www.w3.org/2001/XMLSchema-instance"> <KeyValueOfstringanyType> <Key>key</Key> <Value i:type="a:string" xmlns:a="http://www.w3.org/2001/XMLSchema">Value</Value> </KeyValueOfstringanyType> <KeyValueOfstringanyType> <Key>Key2</Key> <Value i:type="a:decimal" xmlns:a="http://www.w3.org/2001/XMLSchema">100.10</Value> </KeyValueOfstringanyType> <KeyValueOfstringanyType> <Key>Key3</Key> <Value i:type="a:guid" xmlns:a="http://schemas.microsoft.com/2003/10/Serialization/">2cd46d2a-a636-4af4-979b-e834d39b6d37</Value> </KeyValueOfstringanyType> <KeyValueOfstringanyType> <Key>Key4</Key> <Value i:type="a:dateTime" xmlns:a="http://www.w3.org/2001/XMLSchema">2011-09-19T17:17:05.4406999-07:00</Value> </KeyValueOfstringanyType> <KeyValueOfstringanyType> <Key>Key5</Key> <Value i:type="a:boolean" xmlns:a="http://www.w3.org/2001/XMLSchema">true</Value> </KeyValueOfstringanyType> <KeyValueOfstringanyType> <Key>Key7</Key> <Value i:type="a:base64Binary" xmlns:a="http://www.w3.org/2001/XMLSchema">Ki1C</Value> </KeyValueOfstringanyType> </ArrayOfKeyValueOfstringanyType> Ouch! That seriously hurts the eye! :-) Worse though it's extremely verbose with all those repetitive namespace declarations. It's good to know that it works in a pinch, but for a human readable/editable solution or something lightweight to store in a database it's not quite ideal. Why should I care? As a little background, in one of my applications I have a need for a flexible property bag that is used on a free form database field on an otherwise static entity. Basically what I have is a standard database record to which arbitrary properties can be added in an XML based string field. I intend to expose those arbitrary properties as a collection from field data stored in XML. The concept is pretty simple: When loading write the data to the collection, when the data is saved serialize the data into an XML string and store it into the database. When reading the data pick up the XML and if the collection on the entity is accessed automatically deserialize the XML into the Dictionary. (I'll talk more about this in another post). While the DataContext Serializer would work, it's verbosity is problematic both for size of the generated XML strings and the fact that users can manually edit this XML based property data in an advanced mode. A clean(er) layout certainly would be preferable and more user friendly. Custom XMLSerialization with a PropertyBag Class So… after a bunch of experimentation with different serialization formats I decided to create a custom PropertyBag class that provides for a serializable Dictionary. It's basically a custom Dictionary<TType,TValue> implementation with the keys always set as string keys. The result are PropertyBag<TValue> and PropertyBag (which defaults to the object type for values). The PropertyBag<TType> and PropertyBag classes provide these features: Subclassed from Dictionary<T,V> Implements IXmlSerializable with a cleanish XML format ToXml() and FromXml() methods to export and import to and from XML strings Static CreateFromXml() method to create an instance It's simple enough as it's merely a Dictionary<string,object> subclass but that supports serialization to a - what I think at least - cleaner XML format. The class is super simple to use: [TestMethod] public void PropertyBagTwoWayObjectSerializationTest() { var bag = new PropertyBag(); bag.Add("key", "Value"); bag.Add("Key2", 100.10M); bag.Add("Key3", Guid.NewGuid()); bag.Add("Key4", DateTime.Now); bag.Add("Key5", true); bag.Add("Key7", new byte[3] { 42,45,66 } ); bag.Add("Key8", null); bag.Add("Key9", new ComplexObject() { Name = "Rick", Entered = DateTime.Now, Count = 10 }); string xml = bag.ToXml(); TestContext.WriteLine(bag.ToXml()); bag.Clear(); bag.FromXml(xml); Assert.IsTrue(bag["key"] as string == "Value"); Assert.IsInstanceOfType( bag["Key3"], typeof(Guid)); Assert.IsNull(bag["Key8"]); //Assert.IsNull(bag["Key10"]); Assert.IsInstanceOfType(bag["Key9"], typeof(ComplexObject)); } This uses the PropertyBag class which uses a PropertyBag<string,object> - which means it returns untyped values of type object. I suspect for me this will be the most common scenario as I'd want to store arbitrary values in the PropertyBag rather than one specific type. The same code with a strongly typed PropertyBag<decimal> looks like this: [TestMethod] public void PropertyBagTwoWayValueTypeSerializationTest() { var bag = new PropertyBag<decimal>(); bag.Add("key", 10M); bag.Add("Key1", 100.10M); bag.Add("Key2", 200.10M); bag.Add("Key3", 300.10M); string xml = bag.ToXml(); TestContext.WriteLine(bag.ToXml()); bag.Clear(); bag.FromXml(xml); Assert.IsTrue(bag.Get("Key1") == 100.10M); Assert.IsTrue(bag.Get("Key3") == 300.10M); } and produces typed results of type decimal. The types can be either value or reference types the combination of which actually proved to be a little more tricky than anticipated due to null and specific string value checks required - getting the generic typing right required use of default(T) and Convert.ChangeType() to trick the compiler into playing nice. Of course the whole raison d'etre for this class is the XML serialization. You can see in the code above that we're doing a .ToXml() and .FromXml() to serialize to and from string. The XML produced for the first example looks like this: <?xml version="1.0" encoding="utf-8"?> <properties> <item> <key>key</key> <value>Value</value> </item> <item> <key>Key2</key> <value type="decimal">100.10</value> </item> <item> <key>Key3</key> <value type="___System.Guid"> <guid>f7a92032-0c6d-4e9d-9950-b15ff7cd207d</guid> </value> </item> <item> <key>Key4</key> <value type="datetime">2011-09-26T17:45:58.5789578-10:00</value> </item> <item> <key>Key5</key> <value type="boolean">true</value> </item> <item> <key>Key7</key> <value type="base64Binary">Ki1C</value> </item> <item> <key>Key8</key> <value type="nil" /> </item> <item> <key>Key9</key> <value type="___Westwind.Tools.Tests.PropertyBagTest+ComplexObject"> <ComplexObject> <Name>Rick</Name> <Entered>2011-09-26T17:45:58.5789578-10:00</Entered> <Count>10</Count> </ComplexObject> </value> </item> </properties>   The format is a bit cleaner than the DataContractSerializer. Each item is serialized into <key> <value> pairs. If the value is a string no type information is written. Since string tends to be the most common type this saves space and serialization processing. All other types are attributed. Simple types are mapped to XML types so things like decimal, datetime, boolean and base64Binary are encoded using their Xml type values. All other types are embedded with a hokey format that describes the .NET type preceded by a three underscores and then are encoded using the XmlSerializer. You can see this best above in the ComplexObject encoding. For custom types this isn't pretty either, but it's more concise than the DCS and it works as long as you're serializing back and forth between .NET clients at least. The XML generated from the second example that uses PropertyBag<decimal> looks like this: <?xml version="1.0" encoding="utf-8"?> <properties> <item> <key>key</key> <value type="decimal">10</value> </item> <item> <key>Key1</key> <value type="decimal">100.10</value> </item> <item> <key>Key2</key> <value type="decimal">200.10</value> </item> <item> <key>Key3</key> <value type="decimal">300.10</value> </item> </properties>   How does it work As I mentioned there's nothing fancy about this solution - it's little more than a subclass of Dictionary<T,V> that implements custom Xml Serialization and a couple of helper methods that facilitate getting the XML in and out of the class more easily. But it's proven very handy for a number of projects for me where dynamic data storage is required. Here's the code: /// <summary> /// Creates a serializable string/object dictionary that is XML serializable /// Encodes keys as element names and values as simple values with a type /// attribute that contains an XML type name. Complex names encode the type /// name with type='___namespace.classname' format followed by a standard xml /// serialized format. The latter serialization can be slow so it's not recommended /// to pass complex types if performance is critical. /// </summary> [XmlRoot("properties")] public class PropertyBag : PropertyBag<object> { /// <summary> /// Creates an instance of a propertybag from an Xml string /// </summary> /// <param name="xml">Serialize</param> /// <returns></returns> public static PropertyBag CreateFromXml(string xml) { var bag = new PropertyBag(); bag.FromXml(xml); return bag; } } /// <summary> /// Creates a serializable string for generic types that is XML serializable. /// /// Encodes keys as element names and values as simple values with a type /// attribute that contains an XML type name. Complex names encode the type /// name with type='___namespace.classname' format followed by a standard xml /// serialized format. The latter serialization can be slow so it's not recommended /// to pass complex types if performance is critical. /// </summary> /// <typeparam name="TValue">Must be a reference type. For value types use type object</typeparam> [XmlRoot("properties")] public class PropertyBag<TValue> : Dictionary<string, TValue>, IXmlSerializable { /// <summary> /// Not implemented - this means no schema information is passed /// so this won't work with ASMX/WCF services. /// </summary> /// <returns></returns> public System.Xml.Schema.XmlSchema GetSchema() { return null; } /// <summary> /// Serializes the dictionary to XML. Keys are /// serialized to element names and values as /// element values. An xml type attribute is embedded /// for each serialized element - a .NET type /// element is embedded for each complex type and /// prefixed with three underscores. /// </summary> /// <param name="writer"></param> public void WriteXml(System.Xml.XmlWriter writer) { foreach (string key in this.Keys) { TValue value = this[key]; Type type = null; if (value != null) type = value.GetType(); writer.WriteStartElement("item"); writer.WriteStartElement("key"); writer.WriteString(key as string); writer.WriteEndElement(); writer.WriteStartElement("value"); string xmlType = XmlUtils.MapTypeToXmlType(type); bool isCustom = false; // Type information attribute if not string if (value == null) { writer.WriteAttributeString("type", "nil"); } else if (!string.IsNullOrEmpty(xmlType)) { if (xmlType != "string") { writer.WriteStartAttribute("type"); writer.WriteString(xmlType); writer.WriteEndAttribute(); } } else { isCustom = true; xmlType = "___" + value.GetType().FullName; writer.WriteStartAttribute("type"); writer.WriteString(xmlType); writer.WriteEndAttribute(); } // Actual deserialization if (!isCustom) { if (value != null) writer.WriteValue(value); } else { XmlSerializer ser = new XmlSerializer(value.GetType()); ser.Serialize(writer, value); } writer.WriteEndElement(); // value writer.WriteEndElement(); // item } } /// <summary> /// Reads the custom serialized format /// </summary> /// <param name="reader"></param> public void ReadXml(System.Xml.XmlReader reader) { this.Clear(); while (reader.Read()) { if (reader.NodeType == XmlNodeType.Element && reader.Name == "key") { string xmlType = null; string name = reader.ReadElementContentAsString(); // item element reader.ReadToNextSibling("value"); if (reader.MoveToNextAttribute()) xmlType = reader.Value; reader.MoveToContent(); TValue value; if (xmlType == "nil") value = default(TValue); // null else if (string.IsNullOrEmpty(xmlType)) { // value is a string or object and we can assign TValue to value string strval = reader.ReadElementContentAsString(); value = (TValue) Convert.ChangeType(strval, typeof(TValue)); } else if (xmlType.StartsWith("___")) { while (reader.Read() && reader.NodeType != XmlNodeType.Element) { } Type type = ReflectionUtils.GetTypeFromName(xmlType.Substring(3)); //value = reader.ReadElementContentAs(type,null); XmlSerializer ser = new XmlSerializer(type); value = (TValue)ser.Deserialize(reader); } else value = (TValue)reader.ReadElementContentAs(XmlUtils.MapXmlTypeToType(xmlType), null); this.Add(name, value); } } } /// <summary> /// Serializes this dictionary to an XML string /// </summary> /// <returns>XML String or Null if it fails</returns> public string ToXml() { string xml = null; SerializationUtils.SerializeObject(this, out xml); return xml; } /// <summary> /// Deserializes from an XML string /// </summary> /// <param name="xml"></param> /// <returns>true or false</returns> public bool FromXml(string xml) { this.Clear(); // if xml string is empty we return an empty dictionary if (string.IsNullOrEmpty(xml)) return true; var result = SerializationUtils.DeSerializeObject(xml, this.GetType()) as PropertyBag<TValue>; if (result != null) { foreach (var item in result) { this.Add(item.Key, item.Value); } } else // null is a failure return false; return true; } /// <summary> /// Creates an instance of a propertybag from an Xml string /// </summary> /// <param name="xml"></param> /// <returns></returns> public static PropertyBag<TValue> CreateFromXml(string xml) { var bag = new PropertyBag<TValue>(); bag.FromXml(xml); return bag; } } } The code uses a couple of small helper classes SerializationUtils and XmlUtils for mapping Xml types to and from .NET, both of which are from the WestWind,Utilities project (which is the same project where PropertyBag lives) from the West Wind Web Toolkit. The code implements ReadXml and WriteXml for the IXmlSerializable implementation using old school XmlReaders and XmlWriters (because it's pretty simple stuff - no need for XLinq here). Then there are two helper methods .ToXml() and .FromXml() that basically allow your code to easily convert between XML and a PropertyBag object. In my code that's what I use to actually to persist to and from the entity XML property during .Load() and .Save() operations. It's sweet to be able to have a string key dictionary and then be able to turn around with 1 line of code to persist the whole thing to XML and back. Hopefully some of you will find this class as useful as I've found it. It's a simple solution to a common requirement in my applications and I've used the hell out of it in the  short time since I created it. Resources You can find the complete code for the two classes plus the helpers in the Subversion repository for Westwind.Utilities. You can grab the source files from there or download the whole project. You can also grab the full Westwind.Utilities assembly from NuGet and add it to your project if that's easier for you. PropertyBag Source Code SerializationUtils and XmlUtils Westwind.Utilities Assembly on NuGet (add from Visual Studio) © Rick Strahl, West Wind Technologies, 2005-2011Posted in .NET  CSharp   Tweet (function() { var po = document.createElement('script'); po.type = 'text/javascript'; po.async = true; po.src = 'https://apis.google.com/js/plusone.js'; var s = document.getElementsByTagName('script')[0]; s.parentNode.insertBefore(po, s); })();

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  • Generating moderately interesting images

    - by Williham Totland
    Abstract: Can you propose a mathematical-ish algorithm over a plane of pixels that will generate a moderately interesting image, preferably one that on the whole resembles something? The story thus far: Once upon a time I decided in an effort to reduce cycle waste on my (admittedly too) numerous computers, and set out to generate images in a moderately interesting fashion; using a PRNG and some clever math to create images that would, on the whole, resemble something. Or at least, that was the plan. As it turns out, clever math requires being a clever mathematician; this I am not. At some length I arrived at a method that preferred straight lines (as these are generally the components of which our world is made), perhaps too strongly. The result is mildly interesting; resembling, perhaps, city grids as such: Now for the question proper: Given the source code of this little program; can you improve upon it and propose a method that gives somewhat more interesting results? (e.g. not city grids, but perhaps faces, animals, geography, what have you) This is also meant as a sort of challenge; I suppose and as such I've set down some completely arbitrary and equally optional rules: The comments in the code says it all really. Suggestions and "solutions" should edit the algorithm itself, not the surrounding framework, except as for to fix errors that prevents the sample from compiling. The code should compile cleanly with a standard issue C compiler. (If the example provided doesn't, oops! Tell me, and I'll fix. :) The method should, though again, this is optional, not need to elicit help from your friendly neighborhood math library. Solutions should probably be deliverable by simply yanking out whatever is between the snip lines (the ones that say you should not edit above and below, respectively), with a statement to the effect of what you need to add to the preamble in particular. The code requires a C compiler and libpng to build; I'm not entirely confident that the MinGW compiler provides the necessities, but I would be surprised if it didn't. For Debian you'll want the libpng-dev package, and for Mac OS X you'll want the XCode tools.. The source code can be downloaded here. Warning: Massive code splurge incoming! // compile with gcc -o imggen -lpng imggen.c // optionally with -DITERATIONS=x, where x is an appropriate integer // If you're on a Mac or using MinGW, you may have to fiddle with the linker flags to find the library and includes. #include <stdio.h> #include <stdlib.h> #include <png.h> #ifdef ITERATIONS #define REPEAT #endif // ITERATIONS // YOU MAY CHANGE THE FOLLOWING DEFINES #define WIDTH 320 #define HEIGHT 240 // YOU MAY REPLACE THE FOLLOWING DEFINES AS APPROPRIATE #define INK 16384 void writePNG (png_bytepp imageBuffer, png_uint_32 width, png_uint_32 height, int iteration) { char *fname; asprintf(&fname, "out.%d.png", iteration); FILE *fp = fopen(fname, "wb"); if (!fp) return; png_structp png_ptr = png_create_write_struct(PNG_LIBPNG_VER_STRING, NULL, NULL, NULL); png_infop info_ptr = png_create_info_struct(png_ptr); png_init_io(png_ptr, fp); png_set_filter(png_ptr, PNG_FILTER_TYPE_DEFAULT, PNG_FILTER_NONE); png_set_compression_level(png_ptr, Z_BEST_COMPRESSION); png_set_IHDR(png_ptr, info_ptr, width, height, 8, PNG_COLOR_TYPE_GRAY, PNG_INTERLACE_NONE, PNG_COMPRESSION_TYPE_DEFAULT, PNG_FILTER_TYPE_DEFAULT); png_set_rows(png_ptr, info_ptr, imageBuffer); png_set_invert_mono(png_ptr); /// YOU MAY COMMENT OUT THIS LINE png_write_png(png_ptr, info_ptr, PNG_TRANSFORM_IDENTITY, NULL); png_destroy_write_struct(&png_ptr, &info_ptr); fclose(fp); free(fname); } int main (int argc, const char * argv[]) { png_uint_32 height = HEIGHT, width = WIDTH; int iteration = 1; #ifdef REPEAT for (iteration = 1; iteration <= ITERATIONS; iteration++) { #endif // REPEAT png_bytepp imageBuffer = malloc(sizeof(png_bytep) * height); for (png_uint_32 i = 0; i < height; i++) { imageBuffer[i] = malloc(sizeof(png_byte) * width); for (png_uint_32 j = 0; j < width; j++) { imageBuffer[i][j] = 0; } } /// CUT ACROSS THE DASHED LINES /// ------------------------------------------- /// NO EDITING ABOVE THIS LINE; EXCEPT AS NOTED int ink = INK; int x = rand() % width, y = rand() % height; int xdir = (rand() % 2)?1:-1; int ydir = (rand() % 2)?1:-1; while (ink) { imageBuffer[y][x] = 255; --ink; xdir += (rand() % 2)?(1):(-1); ydir += (rand() % 2)?(1):(-1); if (ydir > 0) { ++y; } else if (ydir < 0) { --y; } if (xdir > 0) { ++x; } else if (xdir < 0) { --x; } if (x == -1 || y == -1 || x == width || y == height || x == y && x == 0) { x = rand() % width; y = rand() % height; xdir = (rand() % 2)?1:-1; ydir = (rand() % 2)?1:-1; } } /// NO EDITING BELOW THIS LINE /// ------------------------------------------- writePNG(imageBuffer, width, height, iteration); for (png_uint_32 i = 0; i < height; i++) { free(imageBuffer[i]); } free(imageBuffer); #ifdef REPEAT } #endif // REPEAT return 0; } Note: While this question doesn't strictly speaking seem "answerable" as such; I still believe that it can give rise to some manner of "right" answer. Maybe. Happy hunting.

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  • Storage model for various user setting and attributes in database?

    - by dvd
    I'm currently trying to upgrade a user management system for one web application. This web application is used to provide remote access to various networking equipment for educational purposes. All equipment is assigned to various pods, which users can book for periods of time. The current system is very simple - just 2 user types: administrators and students. All their security and other attributes are mostly hardcoded. I want to change this to something like the following model: user <-- (1..n)profile <--- (1..n) attributes. I.e. user can be assigned several profiles and each profile can have multiple attributes. At runtime all profiles and attributes are merged into single active profile. Some examples of attributes i'm planning to implement: EXPIRATION_DATE - single value, value type: date, specifies when user account will expire; ACCESS_POD - single value, value type: ref to object of Pod class, specifies which pod the user is allowed to book, user profile can have multiple such attributes with different values; TIME_QUOTA - single value, value type: integer, specifies maximum length of time for which student can reserve equipment. CREDIT_CHARGING - multi valued, specifies how much credits will be assigned to user over period of time. (Reservation of devices will cost credits, which will regenerate over time); Security permissions and user preferences can end up as profile or user attributes too: i.e CAN_CREATE_USERS, CAN_POST_NEWS, CAN_EDIT_DEVICES, FONT_SIZE, etc.. This way i could have, for example: students of course A will have profiles STUDENT (with basic attributes) and PROFILE A (wich grants acces to pod A). Students of course B will have profiles: STUDENT, PROFILE B(wich grants to pod B and have increased time quotas). I'm using Spring and Hibernate frameworks for this application and MySQL for database. For this web application i would like to stay within boundaries of these tools. The problem is, that i can't figure out how to best represent all these attributes in database. I also want to create some kind of unified way of retrieveing these attributes and their values. Here is the model i've come up with. Base classes. public abstract class Attribute{ private Long id; Attribute() {} abstract public String getName(); public Long getId() {return id; } void setId(Long id) {this.id = id;} } public abstract class SimpleAttribute extends Attribute{ public abstract Serializable getValue(); abstract void setValue(Serializable s); @Override public boolean equals(Object obj) { ... } @Override public int hashCode() { ... } } Simple attributes can have only one value of any type (including object and enum). Here are more specific attributes: public abstract class IntAttribute extends SimpleAttribute { private Integer value; public Integer getValue() { return value; } void setValue(Integer value) { this.value = value;} void setValue(Serializable s) { setValue((Integer)s); } } public class MaxOrdersAttribute extends IntAttribute { public String getName() { return "Maximum outstanding orders"; } } public final class CreditRateAttribute extends IntAttribute { public String getName() { return "Credit Regeneration Rate"; } } All attributes stored stored using Hibenate variant "table per class hierarchy". Mapping: <class name="ru.mirea.rea.model.abac.Attribute" table="ATTRIBUTES" abstract="true" > <id name="id" column="id"> <generator class="increment" /> </id> <discriminator column="attributeType" type="string"/> <subclass name="ru.mirea.rea.model.abac.SimpleAttribute" abstract="true"> <subclass name="ru.mirea.rea.model.abac.IntAttribute" abstract="true" > <property name="value" column="intVal" type="integer"/> <subclass name="ru.mirea.rea.model.abac.CreditRateAttribute" discriminator-value="CreditRate" /> <subclass name="ru.mirea.rea.model.abac.MaxOrdersAttribute" discriminator-value="MaxOrders" /> </subclass> <subclass name="ru.mirea.rea.model.abac.DateAttribute" abstract="true" > <property name="value" column="dateVal" type="timestamp"/> <subclass name="ru.mirea.rea.model.abac.ExpirationDateAttribute" discriminator-value="ExpirationDate" /> </subclass> <subclass name="ru.mirea.rea.model.abac.PodAttribute" abstract="true" > <many-to-one name="value" column="podVal" class="ru.mirea.rea.model.pods.Pod"/> <subclass name="ru.mirea.rea.model.abac.PodAccessAttribute" discriminator-value="PodAccess" lazy="false"/> </subclass> <subclass name="ru.mirea.rea.model.abac.SecurityPermissionAttribute" discriminator-value="SecurityPermission" lazy="false"> <property name="value" column="spVal" type="ru.mirea.rea.db.hibernate.customTypes.SecurityPermissionType"/> </subclass> </subclass> </class> SecurityPermissionAttribute uses enumeration of various permissions as it's value. Several types of attributes imlement GrantedAuthority interface and can be used with Spring Security for authentication and authorization. Attributes can be created like this: public final class AttributeManager { public <T extends SimpleAttribute> T createSimpleAttribute(Class<T> c, Serializable value) { Session session = HibernateUtil.getCurrentSession(); T att = null; ... att = c.newInstance(); att.setValue(value); session.save(att); session.flush(); ... return att; } public <T extends SimpleAttribute> List<T> findSimpleAttributes(Class<T> c) { List<T> result = new ArrayList<T>(); Session session = HibernateUtil.getCurrentSession(); List<T> temp = session.createCriteria(c).list(); result.addAll(temp); return result; } } And retrieved through User Profiles to which they are assigned. I do not expect that there would be very large amount of rows in the ATTRIBUTES table, but are there any serious drawbacks of such design?

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  • Block Hover Effect - Why doesn't it work correctly in FF3.6?

    - by Brian Ojeda
    Why doesn't following code work correctly in FireFox 3.6? I have tested in IE7, IE8, and Chrome with out any issues. Issue: The first block hover link (the table's 3rd row) doesn't apply the same style/effect as the following below it. Notes: I am trying to create my own table framework. This project is something I am doing to learn more about CSS. Before I started, I thought I knew a lot about CSS. However, to my surprise I was wrong. Who knew? Moving on... As side note, I do not want to take the time to support IE6. So, if you see a problem related IE6, please don't waste your time telling. One another side note, the following style script and HTML listed when this question is strip-down/bare-bone of the complete CSS/HTML. It should be enough to assist me. CSS: /* Main Properties */ .ojtable{display:block;clear:both; margin-left:auto;margin-right:auto; margin-top:0px; width:650px;} .ojtable-row, .ojtable-head {display:block;clear:both;position:relative; margin-left:0px;margin-right:0px;padding:0px;} .col-1, .col-2, .col-3, .col-4, .col-5, .col-6, .col-7, .col-8, .col-9, .col-10, .col-11, .col-12, .col-13, .col-1-b1, .col-2-b1, .col-3-b1, .col-4-b1, .col-5-b1, .col-6-b1, .col-7-b1, .col-8-b1, .col-9-b1, .col-10-b1, .col-11-b1, .col-12-b1, .col-13-b1 {display:block;float:left;position:relative; margin-left:0px;margin-right:0px;padding:0px 2px;} /* Border */ .border-b1{border:solid #000000; border-width:0 0 1px 0;} .border-ltr{border:solid #000000; border-width:1px 1px 0 1px;} /* Header */ .ojtable-row{width:100%;} .ojtable-head{width:100%;} /* No Border*/ .col-2{width:96px;} /* Border: 1px */ .col-2-b1{width:95px;} .col-7-b1{width:345px;} /*--- Clear Floated Elements ---*/ /* Credit: http://sonspring.com/journal/clearing-floats */ .clear { clear: both; display: block; overflow: hidden; visibility: hidden; width: 0; height: 0; } /* Credit: http://perishablepress.com/press/2008/02/05/ lessons-learned-concerning-the-clearfix-css-hack/ */ .clearfix:after { visibility: hidden; display: block; font-size: 0; content: " "; clear: both; height: 0; } .clearfix { display:inline-block; } /* start commented backslash hack \*/ * html .clearfix { height: 1%; } .clearfix { display: block; } /* close commented backslash hack */ /*--- Hover Effect for the Tables ---*/ a {text-decoration:none;} * .ojtable a .ojtable-row{width:650px; display:block; text-decoration:none;} * html .ojtable a .ojtable-row {width:650px;}/* Hover Fix for IE */ .ojtable a:hover .ojtable-row{background:#AAAAAA; cursor:pointer;} HTML: <div class="ojtable border-ltr clearfix"> <div class="ojtable-row border-b1 clearfix"> <div class="col-13">Newest Blogs</div> </div> <div class="ojtable-row border-b1 clearfix"> <div class="col-7-b1 border-r1">Name</div> <div class="col-4-b1 border-r1">Creater's Name</div> <div class="col-2">Dated Created</div> </div> <a href="#"><div class="ojtable-row border-b1 clearfix"> <div class="col-7-b1 border-r1">Why jQuery?</div> <div class="col-4-b1 border-r1">Gramcracker</div> <div class="col-2">Mar 11 2010</div> </div></a> <a href="#"><div class="ojtable-row border-b1 clearfix"> <div class="col-7-b1 border-r1">Thank You For Your Help</div> <div class="col-4-b1 border-r1">O'Hater</div> <div class="col-2">Nov 2 2009</div> </div></a> <a href="#"><div class="ojtable-row border-b1 clearfix"> <div class="col-7-b1 border-r1">Click Me! Hahaha!</div> <div class="col-4-b1 border-r1">Brian Ojeda</div> <div class="col-2">Nov 29 2008</div> </div></a> <a href="#"><div class="ojtable-row border-b1 clearfix"> <div class="col-7-b1 border-r1">Moment of Zen</div> <div class="col-4-b1 border-r1">Jedi</div> <div class="col-2">Mar 11 2010</div> </div></a> <a href="#"><div class="ojtable-row border-b1 clearfix"> <div class="col-7-b1 border-r1"></div> <div class="col-4-b1 border-r1">SGT OJ</div> <div class="col-2">Mar 11 2010</div> </div></a> </div> <!-- End of Table --> PS: Thank you for assistant, if you do choose to help.

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  • WCF timeout exception detailed investigation

    - by Jason Kealey
    We have an application that has a WCF service (*.svc) running on IIS7 and various clients querying the service. The server is running Win 2008 Server. The clients are running either Windows 2008 Server or Windows 2003 server. I am getting the following exception, which I have seen can in fact be related to a large number of potential WCF issues. System.TimeoutException: The request channel timed out while waiting for a reply after 00:00:59.9320000. Increase the timeout value passed to the call to Request or increase the SendTimeout value on the Binding. The time allotted to this operation may have been a portion of a longer timeout. ---> System.TimeoutException: The HTTP request to 'http://www.domain.com/WebServices/myservice.svc/gzip' has exceeded the allotted timeout of 00:01:00. The time allotted to this operation may have been a portion of a longer timeout. I have increased the timeout to 30min and the error still occurred. This tells me that something else is at play, because the quantity of data could never take 30min to upload or download. The error comes and goes. At the moment, it is more frequent. It does not seem to matter if I have 3 clients running simultaneously or 100, it still occurs once in a while. Most of the time, there are no timeouts but I still get a few per hour. The error comes from any of the methods that are invoked. One of these methods does not have parameters and returns a bit of data. Another takes in lots of data as a parameter but executes asynchronously. The errors always originate from the client and never reference any code on the server in the stack trace. It always ends with: at System.Net.HttpWebRequest.GetResponse() at System.ServiceModel.Channels.HttpChannelFactory.HttpRequestChannel.HttpChannelRequest.WaitForReply(TimeSpan timeout) On the server: I've tried (and currently have) the following binding settings: maxBufferSize="2147483647" maxReceivedMessageSize="2147483647" maxBufferPoolSize="2147483647" It does not seem to have an impact. I've tried (and currently have) the following throttling settings: <serviceThrottling maxConcurrentCalls="1500" maxConcurrentInstances="1500" maxConcurrentSessions="1500"/> It does not seem to have an impact. I currently have the following settings for the WCF service. [ServiceBehavior(InstanceContextMode = InstanceContextMode.Single, ConcurrencyMode = ConcurrencyMode.Single)] I ran with ConcurrencyMode.Multiple for a while, and the error still occurred. I've tried restarting IIS, restarting my underlying SQL Server, restarting the machine. All of these don't seem to have an impact. I've tried disabling the Windows firewall. It does not seem to have an impact. On the client, I have these settings: maxReceivedMessageSize="2147483647" <system.net> <connectionManagement> <add address="*" maxconnection="16"/> </connectionManagement> </system.net> My client closes its connections: var client = new MyClient(); try { return client.GetConfigurationOptions(); } finally { client.Close(); } I have changed the registry settings to allow more outgoing connections: MaxConnectionsPerServer=24, MaxConnectionsPer1_0Server=32. I have now just recently tried SvcTraceViewer.exe. I managed to catch one exception on the client end. I see that its duration is 1 minute. Looking at the server side trace, I can see that the server is not aware of this exception. The maximum duration I can see is 10 seconds. I have looked at active database connections using exec sp_who on the server. I only have a few (2-3). I have looked at TCP connections from one client using TCPview. It usually is around 2-3 and I have seen up to 5 or 6. Simply put, I am stumped. I have tried everything I could find, and must be missing something very simple that a WCF expert would be able to see. It is my gut feeling that something is blocking my clients at the low-level (TCP), before the server actually receives the message and/or that something is queuing the messages at the server level and never letting them process. If you have any performance counters I should look at, please let me know. (please indicate what values are bad, as some of these counters are hard to decypher). Also, how could I log the WCF message size? Finally, are there any tools our there that would allow me to test how many connections I can establish between my client and server (independently from my application) Thanks for your time! Extra information added June 20th: My WCF application does something similar to the following. while (true) { Step1GetConfigurationSettingsFromServerViaWCF(); // can change between calls Step2GetWorkUnitFromServerViaWCF(); DoWorkLocally(); // takes 5-15minutes. Step3SendBackResultsToServerViaWCF(); } Using WireShark, I did see that when the error occurs, I have a five TCP retransmissions followed by a TCP reset later on. My guess is the RST is coming from WCF killing the connection. The exception report I get is from Step3 timing out. I discovered this by looking at the tcp stream "tcp.stream eq 192". I then expanded my filter to "tcp.stream eq 192 and http and http.request.method eq POST" and saw 6 POSTs during this stream. This seemed odd, so I checked with another stream such as tcp.stream eq 100. I had three POSTs, which seems a bit more normal because I am doing three calls. However, I do close my connection after every WCF call, so I would have expected one call per stream (but I don't know much about TCP). Investigating a bit more, I dumped the http packet load to disk to look at what these six calls where. 1) Step3 2) Step1 3) Step2 4) Step3 - corrupted 5) Step1 6) Step2 My guess is two concurrent clients are using the same connection, that is why I saw duplicates. However, I still have a few more issues that I can't comprehend: a) Why is the packet corrupted? Random network fluke - maybe? The load is gzipped using this sample code: http://msdn.microsoft.com/en-us/library/ms751458.aspx - Could the code be buggy once in a while when used concurrently? I should test without the gzip library. b) Why would I see step 1 & step 2 running AFTER the corrupted operation timed out? It seems to me as if these operations should not have occurred. Maybe I am not looking at the right stream because my understanding of TCP is flawed. I have other streams that occur at the same time. I should investigate other streams - a quick glance at streams 190-194 show that the Step3 POST have proper payload data (not corrupted). Pushing me to look at the gzip library again.

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  • Creating a thematic map

    - by jsharma
    This post describes how to create a simple thematic map, just a state population layer, with no underlying map tile layer. The map shows states color-coded by total population. The map is interactive with info-windows and can be panned and zoomed. The sample code demonstrates the following: Displaying an interactive vector layer with no background map tile layer (i.e. purpose and use of the Universe object) Using a dynamic (i.e. defined via the javascript client API) color bucket style Dynamically changing a layer's rendering style Specifying which attribute value to use in determining the bucket, and hence style, for a feature (FoI) The result is shown in the screenshot below. The states layer was defined, and stored in the user_sdo_themes view of the mvdemo schema, using MapBuilder. The underlying table is defined as SQL> desc states_32775  Name                                      Null?    Type ----------------------------------------- -------- ----------------------------  STATE                                              VARCHAR2(26)  STATE_ABRV                                         VARCHAR2(2) FIPSST                                             VARCHAR2(2) TOTPOP                                             NUMBER PCTSMPLD                                           NUMBER LANDSQMI                                           NUMBER POPPSQMI                                           NUMBER ... MEDHHINC NUMBER AVGHHINC NUMBER GEOM32775 MDSYS.SDO_GEOMETRY We'll use the TOTPOP column value in the advanced (color bucket) style for rendering the states layers. The predefined theme (US_STATES_BI) is defined as follows. SQL> select styling_rules from user_sdo_themes where name='US_STATES_BI'; STYLING_RULES -------------------------------------------------------------------------------- <?xml version="1.0" standalone="yes"?> <styling_rules highlight_style="C.CB_QUAL_8_CLASS_DARK2_1"> <hidden_info> <field column="STATE" name="Name"/> <field column="POPPSQMI" name="POPPSQMI"/> <field column="TOTPOP" name="TOTPOP"/> </hidden_info> <rule column="TOTPOP"> <features style="states_totpop"> </features> <label column="STATE_ABRV" style="T.BLUE_SERIF_10"> 1 </label> </rule> </styling_rules> SQL> The theme definition specifies that the state, poppsqmi, totpop, state_abrv, and geom columns will be queried from the states_32775 table. The state_abrv value will be used to label the state while the totpop value will be used to determine the color-fill from those defined in the states_totpop advanced style. The states_totpop style, which we will not use in our demo, is defined as shown below. SQL> select definition from user_sdo_styles where name='STATES_TOTPOP'; DEFINITION -------------------------------------------------------------------------------- <?xml version="1.0" ?> <AdvancedStyle> <BucketStyle> <Buckets default_style="C.S02_COUNTRY_AREA"> <RangedBucket seq="0" label="10K - 5M" low="10000" high="5000000" style="C.SEQ6_01" /> <RangedBucket seq="1" label="5M - 12M" low="5000001" high="1.2E7" style="C.SEQ6_02" /> <RangedBucket seq="2" label="12M - 20M" low="1.2000001E7" high="2.0E7" style="C.SEQ6_04" /> <RangedBucket seq="3" label="&gt; 20M" low="2.0000001E7" high="5.0E7" style="C.SEQ6_05" /> </Buckets> </BucketStyle> </AdvancedStyle> SQL> The demo defines additional advanced styles via the OM.style object and methods and uses those instead when rendering the states layer.   Now let's look at relevant snippets of code that defines the map extent and zoom levels (i.e. the OM.universe),  loads the states predefined vector layer (OM.layer), and sets up the advanced (color bucket) style. Defining the map extent and zoom levels. function initMap() {   //alert("Initialize map view");     // define the map extent and number of zoom levels.   // The Universe object is similar to the map tile layer configuration   // It defines the map extent, number of zoom levels, and spatial reference system   // well-known ones (like web mercator/google/bing or maps.oracle/elocation are predefined   // The Universe must be defined when there is no underlying map tile layer.   // When there is a map tile layer then that defines the map extent, srid, and zoom levels.      var uni= new OM.universe.Universe(     {         srid : 32775,         bounds : new OM.geometry.Rectangle(                         -3280000, 170000, 2300000, 3200000, 32775),         numberOfZoomLevels: 8     }); The srid specifies the spatial reference system which is Equal-Area Projection (United States). SQL> select cs_name from cs_srs where srid=32775 ; CS_NAME --------------------------------------------------- Equal-Area Projection (United States) The bounds defines the map extent. It is a Rectangle defined using the lower-left and upper-right coordinates and srid. Loading and displaying the states layer This is done in the states() function. The full code is at the end of this post, however here's the snippet which defines the states VectorLayer.     // States is a predefined layer in user_sdo_themes     var  layer2 = new OM.layer.VectorLayer("vLayer2",     {         def:         {             type:OM.layer.VectorLayer.TYPE_PREDEFINED,             dataSource:"mvdemo",             theme:"us_states_bi",             url: baseURL,             loadOnDemand: false         },         boundingTheme:true      }); The first parameter is a layer name, the second is an object literal for a layer config. The config object has two attributes: the first is the layer definition, the second specifies whether the layer is a bounding one (i.e. used to determine the current map zoom and center such that the whole layer is displayed within the map window) or not. The layer config has the following attributes: type - specifies whether is a predefined one, a defined via a SQL query (JDBC), or in a json-format file (DATAPACK) theme - is the predefined theme's name url - is the location of the mapviewer server loadOnDemand - specifies whether to load all the features or just those that lie within the current map window and load additional ones as needed on a pan or zoom The code snippet below dynamically defines an advanced style and then uses it, instead of the 'states_totpop' style, when rendering the states layer. // override predefined rendering style with programmatic one    var theRenderingStyle =      createBucketColorStyle('YlBr5', colorSeries, 'States5', true);   // specify which attribute is used in determining the bucket (i.e. color) to use for the state   // It can be an array because the style could be a chart type (pie/bar)   // which requires multiple attribute columns     // Use the STATE.TOTPOP column (aka attribute) value here    layer2.setRenderingStyle(theRenderingStyle, ["TOTPOP"]); The style itself is defined in the createBucketColorStyle() function. Dynamically defining an advanced style The advanced style used here is a bucket color style, i.e. a color style is associated with each bucket. So first we define the colors and then the buckets.     numClasses = colorSeries[colorName].classes;    // create Color Styles    for (var i=0; i < numClasses; i++)    {         theStyles[i] = new OM.style.Color(                      {fill: colorSeries[colorName].fill[i],                        stroke:colorSeries[colorName].stroke[i],                       strokeOpacity: useGradient? 0.25 : 1                      });    }; numClasses is the number of buckets. The colorSeries array contains the color fill and stroke definitions and is: var colorSeries = { //multi-hue color scheme #10 YlBl. "YlBl3": {   classes:3,                  fill: [0xEDF8B1, 0x7FCDBB, 0x2C7FB8],                  stroke:[0xB5DF9F, 0x72B8A8, 0x2872A6]   }, "YlBl5": {   classes:5,                  fill:[0xFFFFCC, 0xA1DAB4, 0x41B6C4, 0x2C7FB8, 0x253494],                  stroke:[0xE6E6B8, 0x91BCA2, 0x3AA4B0, 0x2872A6, 0x212F85]   }, //multi-hue color scheme #11 YlBr.  "YlBr3": {classes:3,                  fill:[0xFFF7BC, 0xFEC44F, 0xD95F0E],                  stroke:[0xE6DEA9, 0xE5B047, 0xC5360D]   }, "YlBr5": {classes:5,                  fill:[0xFFFFD4, 0xFED98E, 0xFE9929, 0xD95F0E, 0x993404],                  stroke:[0xE6E6BF, 0xE5C380, 0xE58A25, 0xC35663, 0x8A2F04]     }, etc. Next we create the bucket style.    bucketStyleDef = {       numClasses : colorSeries[colorName].classes, //      classification: 'custom',  //since we are supplying all the buckets //      buckets: theBuckets,       classification: 'logarithmic',  // use a logarithmic scale       styles: theStyles,       gradient:  useGradient? 'linear' : 'off' //      gradient:  useGradient? 'radial' : 'off'     };    theBucketStyle = new OM.style.BucketStyle(bucketStyleDef);    return theBucketStyle; A BucketStyle constructor takes a style definition as input. The style definition specifies the number of buckets (numClasses), a classification scheme (which can be equal-ranged, logarithmic scale, or custom), the styles for each bucket, whether to use a gradient effect, and optionally the buckets (required when using a custom classification scheme). The full source for the demo <!DOCTYPE HTML PUBLIC "-//W3C//DTD HTML 4.01//EN" "http://www.w3.org/TR/html4/strict.dtd"> <html> <head> <meta http-equiv="Content-Type" content="text/html; charset=UTF-8"> <title>Oracle Maps V2 Thematic Map Demo</title> <script src="http://localhost:8080/mapviewer/jslib/v2/oraclemapsv2.js" type="text/javascript"> </script> <script type="text/javascript"> //var $j = jQuery.noConflict(); var baseURL="http://localhost:8080/mapviewer"; // location of mapviewer OM.gv.proxyEnabled =false; // no mvproxy needed OM.gv.setResourcePath(baseURL+"/jslib/v2/images/"); // location of resources for UI elements like nav panel buttons var map = null; // the client mapviewer object var statesLayer = null, stateCountyLayer = null; // The vector layers for states and counties in a state var layerName="States"; // initial map center and zoom var mapCenterLon = -20000; var mapCenterLat = 1750000; var mapZoom = 2; var mpoint = new OM.geometry.Point(mapCenterLon,mapCenterLat,32775); var currentPalette = null, currentStyle=null; // set an onchange listener for the color palette select list // initialize the map // load and display the states layer $(document).ready( function() { $("#demo-htmlselect").change(function() { var theColorScheme = $(this).val(); useSelectedColorScheme(theColorScheme); }); initMap(); states(); } ); /** * color series from ColorBrewer site (http://colorbrewer2.org/). */ var colorSeries = { //multi-hue color scheme #10 YlBl. "YlBl3": { classes:3, fill: [0xEDF8B1, 0x7FCDBB, 0x2C7FB8], stroke:[0xB5DF9F, 0x72B8A8, 0x2872A6] }, "YlBl5": { classes:5, fill:[0xFFFFCC, 0xA1DAB4, 0x41B6C4, 0x2C7FB8, 0x253494], stroke:[0xE6E6B8, 0x91BCA2, 0x3AA4B0, 0x2872A6, 0x212F85] }, //multi-hue color scheme #11 YlBr. "YlBr3": {classes:3, fill:[0xFFF7BC, 0xFEC44F, 0xD95F0E], stroke:[0xE6DEA9, 0xE5B047, 0xC5360D] }, "YlBr5": {classes:5, fill:[0xFFFFD4, 0xFED98E, 0xFE9929, 0xD95F0E, 0x993404], stroke:[0xE6E6BF, 0xE5C380, 0xE58A25, 0xC35663, 0x8A2F04] }, // single-hue color schemes (blues, greens, greys, oranges, reds, purples) "Purples5": {classes:5, fill:[0xf2f0f7, 0xcbc9e2, 0x9e9ac8, 0x756bb1, 0x54278f], stroke:[0xd3d3d3, 0xd3d3d3, 0xd3d3d3, 0xd3d3d3, 0xd3d3d3] }, "Blues5": {classes:5, fill:[0xEFF3FF, 0xbdd7e7, 0x68aed6, 0x3182bd, 0x18519C], stroke:[0xd3d3d3, 0xd3d3d3, 0xd3d3d3, 0xd3d3d3, 0xd3d3d3] }, "Greens5": {classes:5, fill:[0xedf8e9, 0xbae4b3, 0x74c476, 0x31a354, 0x116d2c], stroke:[0xd3d3d3, 0xd3d3d3, 0xd3d3d3, 0xd3d3d3, 0xd3d3d3] }, "Greys5": {classes:5, fill:[0xf7f7f7, 0xcccccc, 0x969696, 0x636363, 0x454545], stroke:[0xd3d3d3, 0xd3d3d3, 0xd3d3d3, 0xd3d3d3, 0xd3d3d3] }, "Oranges5": {classes:5, fill:[0xfeedde, 0xfdb385, 0xfd8d3c, 0xe6550d, 0xa63603], stroke:[0xd3d3d3, 0xd3d3d3, 0xd3d3d3, 0xd3d3d3, 0xd3d3d3] }, "Reds5": {classes:5, fill:[0xfee5d9, 0xfcae91, 0xfb6a4a, 0xde2d26, 0xa50f15], stroke:[0xd3d3d3, 0xd3d3d3, 0xd3d3d3, 0xd3d3d3, 0xd3d3d3] } }; function createBucketColorStyle( colorName, colorSeries, rangeName, useGradient) { var theBucketStyle; var bucketStyleDef; var theStyles = []; var theColors = []; var aBucket, aStyle, aColor, aRange; var numClasses ; numClasses = colorSeries[colorName].classes; // create Color Styles for (var i=0; i < numClasses; i++) { theStyles[i] = new OM.style.Color( {fill: colorSeries[colorName].fill[i], stroke:colorSeries[colorName].stroke[i], strokeOpacity: useGradient? 0.25 : 1 }); }; bucketStyleDef = { numClasses : colorSeries[colorName].classes, // classification: 'custom', //since we are supplying all the buckets // buckets: theBuckets, classification: 'logarithmic', // use a logarithmic scale styles: theStyles, gradient: useGradient? 'linear' : 'off' // gradient: useGradient? 'radial' : 'off' }; theBucketStyle = new OM.style.BucketStyle(bucketStyleDef); return theBucketStyle; } function initMap() { //alert("Initialize map view"); // define the map extent and number of zoom levels. // The Universe object is similar to the map tile layer configuration // It defines the map extent, number of zoom levels, and spatial reference system // well-known ones (like web mercator/google/bing or maps.oracle/elocation are predefined // The Universe must be defined when there is no underlying map tile layer. // When there is a map tile layer then that defines the map extent, srid, and zoom levels. var uni= new OM.universe.Universe( { srid : 32775, bounds : new OM.geometry.Rectangle( -3280000, 170000, 2300000, 3200000, 32775), numberOfZoomLevels: 8 }); map = new OM.Map( document.getElementById('map'), { mapviewerURL: baseURL, universe:uni }) ; var navigationPanelBar = new OM.control.NavigationPanelBar(); map.addMapDecoration(navigationPanelBar); } // end initMap function states() { //alert("Load and display states"); layerName = "States"; if(statesLayer) { // states were already visible but the style may have changed // so set the style to the currently selected one var theData = $('#demo-htmlselect').val(); setStyle(theData); } else { // States is a predefined layer in user_sdo_themes var layer2 = new OM.layer.VectorLayer("vLayer2", { def: { type:OM.layer.VectorLayer.TYPE_PREDEFINED, dataSource:"mvdemo", theme:"us_states_bi", url: baseURL, loadOnDemand: false }, boundingTheme:true }); // add drop shadow effect and hover style var shadowFilter = new OM.visualfilter.DropShadow({opacity:0.5, color:"#000000", offset:6, radius:10}); var hoverStyle = new OM.style.Color( {stroke:"#838383", strokeThickness:2}); layer2.setHoverStyle(hoverStyle); layer2.setHoverVisualFilter(shadowFilter); layer2.enableFeatureHover(true); layer2.enableFeatureSelection(false); layer2.setLabelsVisible(true); // override predefined rendering style with programmatic one var theRenderingStyle = createBucketColorStyle('YlBr5', colorSeries, 'States5', true); // specify which attribute is used in determining the bucket (i.e. color) to use for the state // It can be an array because the style could be a chart type (pie/bar) // which requires multiple attribute columns // Use the STATE.TOTPOP column (aka attribute) value here layer2.setRenderingStyle(theRenderingStyle, ["TOTPOP"]); currentPalette = "YlBr5"; var stLayerIdx = map.addLayer(layer2); //alert('State Layer Idx = ' + stLayerIdx); map.setMapCenter(mpoint); map.setMapZoomLevel(mapZoom) ; // display the map map.init() ; statesLayer=layer2; // add rt-click event listener to show counties for the state layer2.addListener(OM.event.MouseEvent.MOUSE_RIGHT_CLICK,stateRtClick); } // end if } // end states function setStyle(styleName) { // alert("Selected Style = " + styleName); // there may be a counties layer also displayed. // that wll have different bucket ranges so create // one style for states and one for counties var newRenderingStyle = null; if (layerName === "States") { if(/3/.test(styleName)) { newRenderingStyle = createBucketColorStyle(styleName, colorSeries, 'States3', false); currentStyle = createBucketColorStyle(styleName, colorSeries, 'Counties3', false); } else { newRenderingStyle = createBucketColorStyle(styleName, colorSeries, 'States5', false); currentStyle = createBucketColorStyle(styleName, colorSeries, 'Counties5', false); } statesLayer.setRenderingStyle(newRenderingStyle, ["TOTPOP"]); if (stateCountyLayer) stateCountyLayer.setRenderingStyle(currentStyle, ["TOTPOP"]); } } // end setStyle function stateRtClick(evt){ var foi = evt.feature; //alert('Rt-Click on State: ' + foi.attributes['_label_'] + // ' with pop ' + foi.attributes['TOTPOP']); // display another layer with counties info // layer may change on each rt-click so create and add each time. var countyByState = null ; // the _label_ attribute of a feature in this case is the state abbreviation // we will use that to query and get the counties for a state var sqlText = "select totpop,geom32775 from counties_32775_moved where state_abrv="+ "'"+foi.getAttributeValue('_label_')+"'"; // alert(sqlText); if (currentStyle === null) currentStyle = createBucketColorStyle('YlBr5', colorSeries, 'Counties5', false); /* try a simple style instead new OM.style.ColorStyle( { stroke: "#B8F4FF", fill: "#18E5F4", fillOpacity:0 } ); */ // remove existing layer if any if(stateCountyLayer) map.removeLayer(stateCountyLayer); countyByState = new OM.layer.VectorLayer("stCountyLayer", {def:{type:OM.layer.VectorLayer.TYPE_JDBC, dataSource:"mvdemo", sql:sqlText, url:baseURL}}); // url:baseURL}, // renderingStyle:currentStyle}); countyByState.setVisible(true); // specify which attribute is used in determining the bucket (i.e. color) to use for the state countyByState.setRenderingStyle(currentStyle, ["TOTPOP"]); var ctLayerIdx = map.addLayer(countyByState); // alert('County Layer Idx = ' + ctLayerIdx); //map.addLayer(countyByState); stateCountyLayer = countyByState; } // end stateRtClick function useSelectedColorScheme(theColorScheme) { if(map) { // code to update renderStyle goes here //alert('will try to change render style'); setStyle(theColorScheme); } else { // do nothing } } </script> </head> <body bgcolor="#b4c5cc" style="height:100%;font-family:Arial,Helvetica,Verdana"> <h3 align="center">State population thematic map </h3> <div id="demo" style="position:absolute; left:68%; top:44px; width:28%; height:100%"> <HR/> <p/> Choose Color Scheme: <select id="demo-htmlselect"> <option value="YlBl3"> YellowBlue3</option> <option value="YlBr3"> YellowBrown3</option> <option value="YlBl5"> YellowBlue5</option> <option value="YlBr5" selected="selected"> YellowBrown5</option> <option value="Blues5"> Blues</option> <option value="Greens5"> Greens</option> <option value="Greys5"> Greys</option> <option value="Oranges5"> Oranges</option> <option value="Purples5"> Purples</option> <option value="Reds5"> Reds</option> </select> <p/> </div> <div id="map" style="position:absolute; left:10px; top:50px; width:65%; height:75%; background-color:#778f99"></div> <div style="position:absolute;top:85%; left:10px;width:98%" class="noprint"> <HR/> <p> Note: This demo uses HTML5 Canvas and requires IE9+, Firefox 10+, or Chrome. No map will show up in IE8 or earlier. </p> </div> </body> </html>

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  • Why Java servlet can't get Paypal IPN messages everytime ?

    - by Frank
    I have a Java servlet running on my notebook with Windows Vista, I set up a static IP, did port forwarding and registered for a free DDNS service, now my servlet is running, I gave the url to Paypal to send me IPN messages, I went on to it's sandbox site got to the test tools page, tried to send test messages by clicking the "Send IPN" button, most of the time it would fail, the error is : "IPN delivery failed. Unable to connect to the specified URL. Please verify the URL and try again." But maybe 1 in 10 times, it might be successful and my servlet would get the message, and I looked at the messages I got, they are in correct format. So I called Paypal asking why, he said I shouldn't run the servlet on my notebook, in stead I should run it on the web server, but I told him my ISP doesn't support Java on their server, and since I did all the above steps, shouldn't it be the same to run the servlet on my notebook ? He said his test showed he couldn't get to my servlet, but I asked why maybe 1 in 10 times it could get through ? If there is something wrong with running it on my notebook, then 100% times it should fail, am I correct on this point ? But anyway he said that's all he could do, and I should troubleshoot it myself. The servlet looks like this : import java.io.*; import java.net.*; import javax.servlet.*; import javax.servlet.http.*; import java.util.*; public class PayPal_Servlet extends HttpServlet { static boolean Debug=true; static String PayPal_Url="https://www.paypal.com/cgi-bin/webscr",Sandbox_Url="https://www.sandbox.paypal.com/cgi-bin/webscr", Dir_License_Messages="C:/Dir_License_Messages/"; static TransparencyExample Transparency_Example; static PayPal_Message_To_License_File_Worker PayPal_message_to_license_file_worker; // Initializes the servlet. public void init(ServletConfig config) throws ServletException { super.init(config); if (!new File(Dir_License_Messages).exists()) new File(Dir_License_Messages).mkdirs(); System.gc(); } /** Processes requests for both HTTP <code>GET</code> and <code>POST</code> methods. * @param request servlet request * @param response servlet response */ protected void processRequest(HttpServletRequest request,HttpServletResponse response) throws ServletException,IOException { // Read post from PayPal system and add 'cmd' Enumeration en=request.getParameterNames(); String str="cmd=_notify-validate"; while (en.hasMoreElements()) { String paramName=(String)en.nextElement(); String paramValue=request.getParameter(paramName); str=str+"&"+paramName+"="+URLEncoder.encode(paramValue); } // Post back to PayPal system to validate // NOTE: change http: to https: in the following URL to verify using SSL (for increased security). // using HTTPS requires either Java 1.4 or greater, or Java Secure Socket Extension (JSSE) and configured for older versions. URL u=new URL(Debug?Sandbox_Url:PayPal_Url); URLConnection uc=u.openConnection(); uc.setDoOutput(true); uc.setRequestProperty("Content-Type","application/x-www-form-urlencoded"); PrintWriter pw=new PrintWriter(uc.getOutputStream()); pw.println(str); pw.close(); BufferedReader in=new BufferedReader(new InputStreamReader(uc.getInputStream())); String res=in.readLine(); in.close(); // Assign posted variables to local variables String itemName=request.getParameter("item_name"); String itemNumber=request.getParameter("item_number"); String paymentStatus=request.getParameter("payment_status"); String paymentAmount=request.getParameter("mc_gross"); String paymentCurrency=request.getParameter("mc_currency"); String txnId=request.getParameter("txn_id"); String receiverEmail=request.getParameter("receiver_email"); String payerEmail=request.getParameter("payer_email"); if (res.equals("VERIFIED")) // Check notification validation { // check that paymentStatus=Completed // check that txnId has not been previously processed // check that receiverEmail is your Primary PayPal email // check that paymentAmount/paymentCurrency are correct // process payment } else if (res.equals("INVALID")) // Log for investigation { } else // Log for error { } // =========================================================================== if (txnId!=null) { Write_File_Safe_Fast(Dir_License_Messages+txnId+".txt",new StringBuffer(str.replace("&","\n")),false); } // =========================================================================== String Message_File_List[]=Tool_Lib.Get_File_List_From_Dir(Dir_License_Messages); response.setContentType("text/html"); PrintWriter out=response.getWriter(); String title="Reading All Request Parameters",Name="",Value; out.println("<Html><Head><Title>"+title+"</Title></Head>\n<Body Bgcolor=\"#FDF5E6\">\n<H1 Align=Center>"+title+"</H1>\n"+ "<Table Border=1 Align=Center>\n"+"<Tr Bgcolor=\"#FFAD00\"><Th>Parameter Name</Th><Th>Parameter Value(s) Messages = "+Message_File_List.length+"</Th></Tr>"); Enumeration paramNames=request.getParameterNames(); while(paramNames.hasMoreElements()) { String paramName=(String)paramNames.nextElement(); out.print("<Tr><Td>"+paramName+"</Td><Td>"); String[] paramValues=request.getParameterValues(paramName); if (paramValues.length == 1) { String paramValue=paramValues[0]; if (paramValue.length() == 0) out.print("<I>No Value</I>"); else { out.println(paramValue+"</Td></Tr>"); // Out("paramName = "+paramName+" paramValue = "+paramValue); // if (paramName.startsWith("Name")) Name=paramValue; // else if (paramName.startsWith("Value")) Write_File_Safe_Fast("C:/Dir_Data/"+Name,new StringBuffer(paramValue),false); } } else { out.println("<Ul>"); for (int i=0;i<paramValues.length;i++) out.println("<Li>"+paramValues[i]); out.println("</Ul></Td</Tr>"); } } out.println("</Table>\n</Body></Html>"); } /** Handles the HTTP <code>GET</code> method. * @param request servlet request * @param response servlet response */ protected void doGet(HttpServletRequest request,HttpServletResponse response) throws ServletException,IOException { processRequest(request,response); } /** Handles the HTTP <code>POST</code> method. * @param request servlet request * @param response servlet response */ protected void doPost(HttpServletRequest request,HttpServletResponse response) throws ServletException,IOException { processRequest(request,response); } // Returns a short description of the servlet. public String getServletInfo() { return "Short description"; } // Destroys the servlet. public void destroy() { System.gc(); } public static void Write_File_Safe_Fast(String File_Path,StringBuffer Str_Buf,boolean Append) { FileOutputStream fos=null; BufferedOutputStream bos=null; try { fos=new FileOutputStream(File_Path,Append); bos=new BufferedOutputStream(fos); for (int j=0;j<Str_Buf.length();j++) bos.write(Str_Buf.charAt(j)); } catch (Exception e) { e.printStackTrace(); } finally { try { if (bos!=null) { bos.close(); bos=null; } if (fos!=null) { fos.close(); fos=null; } } catch (Exception ex) { ex.printStackTrace(); } } System.gc(); } } I use Netbean6.7 to develop the servlet, and the code was from Paypal's JSP sample code, what can I do to debug the problem ?

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  • Dojo - How to position tooltip close to text?

    - by user244394
    Like the title says i want to be able to display the tooltip close to the text, currently it is displayed far away in the cell. Tobe noted the tooltip positions correctly for large text, only fails for small text. In DOJO How can i position the tooltip close to the text? I have this bit of code snippet that display the tooltip in the grid cells. Screenshot attached, html <div class="some_app claro"></div> ... com.c.widget.EnhancedGrid = function ( aParent, options ) { var grid, options; this.theParentApp = aParent; dojo.require("dojox.grid.EnhancedGrid"); dojo.require("dojox.grid.enhanced.plugins.Menu"); dojo.require("dojox.grid.enhanced.plugins.Selector"); dojo.require("dojox.grid.enhanced.plugins.Pagination"); dojo.require("dojo.store.Memory"); dojo.require("dojo.data.ObjectStore"); dojo.require("dojo._base.xhr"); dojo.require("dojo.domReady!"); dojo.require("dojo.date.locale"); dojo.require("dojo._base.connect"); dojo.require("dojox.data.JsonRestStore"); dojo.require("dojo.data.ItemFileReadStore"); dojo.require("dijit.Menu"); dojo.require("dijit.MenuItem"); dojo.require('dijit.MenuSeparator'); dojo.require('dijit.CheckedMenuItem'); dojo.require('dijit.Tooltip'); dojo.require('dojo/query'); dojo.require("dojox.data.QueryReadStore"); // main initialization function this.init = function( options ) { var me = this; // default options var defaultOptions = { widgetName: ' Enhancedgrid', render: true, // immediately render the grid draggable: true, // disables column dragging containerNode: false, // the Node to hold the Grid (optional) mashupUrl: false, // the URL of the mashup (required) rowsPerPage: 20, //Default number of items per page columns: false, // columns (required) width: "100%", // width of grid height: "100%", // height of grid rowClass: function (rowData) {}, onClick: function () {}, headerMenu: false, // adding a menu pop-up for the header. selectedRegionMenu: false, // adding a menu pop-up for the rows. menusObject: false, //object to start-up the menus using the plug-in. sortInfo: false, // The column default sort infiniteScrolling: false //If true, the enhanced grid will have an infinite scrolling. }; // merge user provided options me.options = jQuery.extend( {}, defaultOptions, options ); // check we have minimum required options if ( ! me.options.mashupUrl ){ throw ("You must supply a mashupUrl"); } if ( ! me.options.columns ){ throw ("You must supply columns"); } // make the column for formatting based on its data type. me.preProcessColumns(); // create the Contextual Menu me.createMenu(); // create the grid object and return me.createGrid(); }; // Loading the data to the grid. this.loadData = function () { var me = this; if (!me.options.infiniteScrolling) { var xhrArgs = { url: me.options.mashupUrl, handleAs: "json", load: function( data ){ var store = new dojo.data.ItemFileReadStore({ data : {items : eval( "data."+me.options.dataRoot)}}); store.fetch({ onComplete : function(items, request) { if (me.grid.selection !== null) { me.grid.selection.clear(); } me.grid.setStore(store); }, onError : function(error) { me.onError(error); } }); }, error: function (error) { me.onError(error); } }; dojo.xhrGet(xhrArgs); } else { dojo.declare('NotificationQueryReadStore', dojox.data.QueryReadStore, { // // hacked -- override to map to proper data structure // from mashup // _xhrFetchHandler : function(data, request, fetchHandler, errorHandler) { // // TODO: need to have error handling here when // data has "error" data structure // // // remap data object before process by super method // var dataRoot = eval ("data."+me.options.dataRoot); var dataTotal = eval ("data."+me.options.dataTotal); data = { numRows : dataTotal, items : dataRoot }; // call to super method to process mapped data and // set rowcount // for proper display this.inherited(arguments); } }); var queryStore = new NotificationQueryReadStore({ url : me.options.mashupUrl, urlPreventCache: true, requestMethod : "get", onError: function (error) { me.onError(error); } }); me.grid.setStore(queryStore); } }; this.preProcessColumns = function () { var me = this; var options = me.options; for (i=0;i<this.options.columns.length;i++) { if (this.options.columns[i].formatter==null) { switch (this.options.columns[i].datatype) { case "string": this.options.columns[i].formatter = me.formatString; break; case "date": this.options.columns[i].formatter = me.formatDate; var todayDate = new Date(); var gmtTime = c.util.Date.parseDate(todayDate.toString()).toString(); var gmtval = gmtTime.substring(gmtTime.indexOf('GMT'),(gmtTime.indexOf('(')-1)); this.options.columns[i].name = this.options.columns[i].name + " ("+gmtval+")"; } } if (this.options.columns[i].sortDefault) { me.options.sortInfo = i+1; } } }; // create GRID object using supplied options this.createGrid = function () { var me = this; var options = me.options; // create a new grid this.grid = new dojox.grid.EnhancedGrid ({ width: options.width, height: options.height, query: { id: "*" }, keepSelection: true, formatterScope: this, structure: options.columns, columnReordering: options.draggable, rowsPerPage: options.rowsPerPage, //sortInfo: options.sortInfo, plugins : { menus: options.menusObject, selector: {"row":"multi", "cell": "disabled" }, }, //Allow the user to decide if a column is sortable by setting sortable = true / false canSort: function(col) { if (options.columns[Math.abs(col)-1].sortable) return true; else return false; }, //Change the row colors depending on severity column. onStyleRow: function (row) { var grid = me.grid; var item = grid.getItem(row.index); if (item && options.rowClass(item)) { row.customClasses += " " +options.rowClass(item); if (grid.selection.selectedIndex == row.index) { row.customClasses += " dojoxGridRowSelected"; } grid.focus.styleRow(row); grid.edit.styleRow(row); } }, onCellMouseOver: function (e){ // var pos = dojo.position(this, true); // alert(pos); console.log( e.rowIndex +" cell node :"+ e.cellNode.innerHTML); // var pos = dojo.position(this, true); console.log( " pos :"+ e.pos); if (e.cellNode.innerHTML!="") { dijit.showTooltip(e.cellNode.innerHTML, e.cellNode); } }, onCellMouseOut: function (e){ dijit.hideTooltip(e.cellNode); }, onHeaderCellMouseOver: function (e){ if (e.cellNode.innerHTML!="") { dijit.showTooltip(e.cellNode.innerHTML, e.cellNode); } }, onHeaderCellMouseOut: function (e){ dijit.hideTooltip(e.cellNode); }, }); // ADDED CODE FOR TOOLTIP var gridTooltip = new Tooltip({ connectId: "grid1", selector: "td", position: ["above"], getContent: function(matchedNode){ var childNode = matchedNode.childNodes[0]; if(childNode.nodeType == 1 && childNode.className == "user") { this.position = ["after"]; this.open(childNode); return false; } if(matchedNode.className && matchedNode.className == "user") { this.position = ["after"]; } else { this.position = ["above"]; } return matchedNode.textContent; } }); ... //Construct the grid this.buildGrid = function(){ var datagrid = new com.emc.widget.EnhancedGrid(this,{ Url: "/dge/api/-resultFormat=json&id="+encodeURIComponent(idUrl), dataRoot: "Root.ATrail", height: '100%', columns: [ { name: 'Time', field: 'Time', width: '20%', datatype: 'date', sortable: true, searchable: true, hidden: false}, { name: 'Type', field: 'Type', width: '20%', datatype: 'string', sortable: true, searchable: true, hidden: false}, { name: 'User ID', field: 'UserID', width: '20%', datatype: 'string', sortable: true, searchable: true, hidden: false } ] }); this.grid = datagrid; };

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  • Marshalling to a native library in C#

    - by Daniel Baulig
    I'm having trouble calling functions of a native library from within managed C# code. I am developing for the 3.5 compact framework (Windows Mobile 6.x) just in case this would make any difference. I am working with the waveIn* functions from coredll.dll (these are in winmm.dll in regular Windows I believe). This is what I came up with: // namespace winmm; class winmm [StructLayout(LayoutKind.Sequential)] public struct WAVEFORMAT { public ushort wFormatTag; public ushort nChannels; public uint nSamplesPerSec; public uint nAvgBytesPerSec; public ushort nBlockAlign; public ushort wBitsPerSample; public ushort cbSize; } [StructLayout(LayoutKind.Sequential)] public struct WAVEHDR { public IntPtr lpData; public uint dwBufferLength; public uint dwBytesRecorded; public IntPtr dwUser; public uint dwFlags; public uint dwLoops; public IntPtr lpNext; public IntPtr reserved; } public delegate void AudioRecordingDelegate(IntPtr deviceHandle, uint message, IntPtr instance, ref WAVEHDR wavehdr, IntPtr reserved2); [DllImport("coredll.dll")] public static extern int waveInAddBuffer(IntPtr hWaveIn, ref WAVEHDR lpWaveHdr, uint cWaveHdrSize); [DllImport("coredll.dll")] public static extern int waveInPrepareHeader(IntPtr hWaveIn, ref WAVEHDR lpWaveHdr, uint Size); [DllImport("coredll.dll")] public static extern int waveInStart(IntPtr hWaveIn); // some other class private WinMM.WinMM.AudioRecordingDelegate waveIn; private IntPtr handle; private uint bufferLength; private void setupBuffer() { byte[] buffer = new byte[bufferLength]; GCHandle bufferPin = GCHandle.Alloc(buffer, GCHandleType.Pinned); WinMM.WinMM.WAVEHDR hdr = new WinMM.WinMM.WAVEHDR(); hdr.lpData = bufferPin.AddrOfPinnedObject(); hdr.dwBufferLength = this.bufferLength; hdr.dwFlags = 0; int i = WinMM.WinMM.waveInPrepareHeader(this.handle, ref hdr, Convert.ToUInt32(Marshal.SizeOf(hdr))); if (i != WinMM.WinMM.MMSYSERR_NOERROR) { this.Text = "Error: waveInPrepare"; return; } i = WinMM.WinMM.waveInAddBuffer(this.handle, ref hdr, Convert.ToUInt32(Marshal.SizeOf(hdr))); if (i != WinMM.WinMM.MMSYSERR_NOERROR) { this.Text = "Error: waveInAddrBuffer"; return; } } private void setupWaveIn() { WinMM.WinMM.WAVEFORMAT format = new WinMM.WinMM.WAVEFORMAT(); format.wFormatTag = WinMM.WinMM.WAVE_FORMAT_PCM; format.nChannels = 1; format.nSamplesPerSec = 8000; format.wBitsPerSample = 8; format.nBlockAlign = Convert.ToUInt16(format.nChannels * format.wBitsPerSample); format.nAvgBytesPerSec = format.nSamplesPerSec * format.nBlockAlign; this.bufferLength = format.nAvgBytesPerSec; format.cbSize = 0; int i = WinMM.WinMM.waveInOpen(out this.handle, WinMM.WinMM.WAVE_MAPPER, ref format, Marshal.GetFunctionPointerForDelegate(waveIn), 0, WinMM.WinMM.CALLBACK_FUNCTION); if (i != WinMM.WinMM.MMSYSERR_NOERROR) { this.Text = "Error: waveInOpen"; return; } setupBuffer(); WinMM.WinMM.waveInStart(this.handle); } I read alot about marshalling the last few days, nevertheless I do not get this code working. When my callback function is called (waveIn) when the buffer is full, the hdr structure passed back in wavehdr is obviously corrupted. Here is an examlpe of how the structure looks like at that point: - wavehdr {WinMM.WinMM.WAVEHDR} WinMM.WinMM.WAVEHDR dwBufferLength 0x19904c00 uint dwBytesRecorded 0x0000fa00 uint dwFlags 0x00000003 uint dwLoops 0x1990f6a4 uint + dwUser 0x00000000 System.IntPtr + lpData 0x00000000 System.IntPtr + lpNext 0x00000000 System.IntPtr + reserved 0x7c07c9a0 System.IntPtr This obiously is not what I expected to get passed. I am clearly concerned about the order of the fields in the view. I do not know if Visual Studio .NET cares about actual memory order when displaying the record in the "local"-view, but they are obviously not displayed in the order I speciefied in the struct. Then theres no data pointer and the bufferLength field is far to high. Interestingly the bytesRecorded field is exactly 64000 - bufferLength and bytesRecorded I'd expect both to be 64000 though. I do not know what exactly is going wrong, maybe someone can help me out on this. I'm an absolute noob to managed code programming and marshalling so please don't be too harsh to me for all the stupid things I've propably done. Oh here's the C code definition for WAVEHDR which I found here, I believe I might have done something wrong in the C# struct definition: /* wave data block header */ typedef struct wavehdr_tag { LPSTR lpData; /* pointer to locked data buffer */ DWORD dwBufferLength; /* length of data buffer */ DWORD dwBytesRecorded; /* used for input only */ DWORD_PTR dwUser; /* for client's use */ DWORD dwFlags; /* assorted flags (see defines) */ DWORD dwLoops; /* loop control counter */ struct wavehdr_tag FAR *lpNext; /* reserved for driver */ DWORD_PTR reserved; /* reserved for driver */ } WAVEHDR, *PWAVEHDR, NEAR *NPWAVEHDR, FAR *LPWAVEHDR; If you are used to work with all those low level tools like pointer-arithmetic, casts, etc starting writing managed code is a pain in the ass. It's like trying to learn how to swim with your hands tied on your back. Some things I tried (to no effect): .NET compact framework does not seem to support the Pack = 2^x directive in [StructLayout]. I tried [StructLayout(LayoutKind.Explicit)] and used 4 bytes and 8 bytes alignment. 4 bytes alignmentgave me the same result as the above code and 8 bytes alignment only made things worse - but that's what I expected. Interestingly if I move the code from setupBuffer into the setupWaveIn and do not declare the GCHandle in the context of the class but in a local context of setupWaveIn the struct returned by the callback function does not seem to be corrupted. I am not sure however why this is the case and how I can use this knowledge to fix my code. I'd really appreciate any good links on marshalling, calling unmanaged code from C#, etc. Then I'd be very happy if someone could point out my mistakes. What am I doing wrong? Why do I not get what I'd expect.

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  • Need Help Customizing a Grammar Checking Replace Rule in Java

    - by user567785
    Hello, I am currently adding the Khmer (Cambodian) language to LanguageTool, an opensource grammar checker for OpenOffice (http://www.languagetool.org). I don't know enough Java to customize one of the scripts and wanted to make a request here asking if anyone would be willing to customize it for me (I can put link to your website at http://www.sbbic.org/lang/en-us/volunteer/ if you help). Here is the script that needs customization KhmerWordCoherencyRule.java: /* LanguageTool, a natural language style checker * Copyright (C) 2005 Daniel Naber (http://www.danielnaber.de) * * This library is free software; you can redistribute it and/or * modify it under the terms of the GNU Lesser General Public * License as published by the Free Software Foundation; either * version 2.1 of the License, or (at your option) any later version. * * This library is distributed in the hope that it will be useful, * but WITHOUT ANY WARRANTY; without even the implied warranty of * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU * Lesser General Public License for more details. * * You should have received a copy of the GNU Lesser General Public * License along with this library; if not, write to the Free Software * Foundation, Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 * USA */ package de.danielnaber.languagetool.rules.km; import java.io.BufferedReader; import java.io.IOException; import java.io.InputStream; import java.io.InputStreamReader; import java.util.ArrayList; import java.util.HashMap; import java.util.List; import java.util.Locale; import java.util.Map; import java.util.ResourceBundle; import de.danielnaber.languagetool.AnalyzedSentence; import de.danielnaber.languagetool.AnalyzedToken; import de.danielnaber.languagetool.AnalyzedTokenReadings; import de.danielnaber.languagetool.JLanguageTool; import de.danielnaber.languagetool.tools.StringTools; import de.danielnaber.languagetool.rules.Category; import de.danielnaber.languagetool.rules.RuleMatch; /** * A Khmer rule that matches words or phrases which should not be used and suggests * correct ones instead. Loads the relevant words from * <code>rules/km/coherency.txt</code>, where km is a code of the language. * * @author Andriy Rysin */ public abstract class KhmerWordCoherencyRule extends KhmerRule { private static final String FILE_ENCODING = "utf-8"; private Map<String, String> wrongWords; // e.g. "????? -> "?????" private static final String FILE_NAME = "/km/coherency.txt"; public abstract String getFileName(); public String getEncoding() { return FILE_ENCODING; } /** * Indicates if the rule is case-sensitive. Default value is <code>true</code>. * @return true if the rule is case-sensitive, false otherwise. */ //in Khmer there is no case public boolean isCaseSensitive() { return false; } /** * @return the locale used for case conversion when {@link #isCaseSensitive()} is set to <code>false</code>. */ public Locale getLocale() { return Locale.getDefault(); } public KhmerWordCoherencyRule(final ResourceBundle messages) throws IOException { if (messages != null) { super.setCategory(new Category(messages.getString("category_misc"))); } wrongWords = loadWords(JLanguageTool.getDataBroker().getFromRulesDirAsStream(getFileName())); } public String getId() { return "KM_WORD_COHERENCY"; } public String getDescription() { return "Checks for wrong words/phrases"; } public String getSuggestion() { return " does not match your previous spelling of the word, use "; } public String getShort() { return "Use a consistant spelling throughout"; } public final RuleMatch[] match(final AnalyzedSentence text) { final List<RuleMatch> ruleMatches = new ArrayList<RuleMatch>(); final AnalyzedTokenReadings[] tokens = text.getTokensWithoutWhitespace(); for (int i = 1; i < tokens.length; i++) { final String token = tokens[i].getToken(); final String origToken = token; final String replacement = isCaseSensitive()?wrongWords.get(token):wrongWords.get(token.toLowerCase(getLocale())); if (replacement != null) { final String msg = token + getSuggestion() + replacement; final int pos = tokens[i].getStartPos(); final RuleMatch potentialRuleMatch = new RuleMatch(this, pos, pos + origToken.length(), msg, getShort()); if (!isCaseSensitive() && StringTools.startsWithUppercase(token)) { potentialRuleMatch.setSuggestedReplacement(StringTools.uppercaseFirstChar(replacement)); } else { potentialRuleMatch.setSuggestedReplacement(replacement); } ruleMatches.add(potentialRuleMatch); } } return toRuleMatchArray(ruleMatches); } private Map<String, String> loadWords(final InputStream file) throws IOException { final Map<String, String> map = new HashMap<String, String>(); InputStreamReader isr = null; BufferedReader br = null; try { isr = new InputStreamReader(file, getEncoding()); br = new BufferedReader(isr); String line; while ((line = br.readLine()) != null) { line = line.trim(); if (line.length() < 1) { continue; } if (line.charAt(0) == '#') { // ignore comments continue; } final String[] parts = line.split(";"); if (parts.length != 2) { throw new IOException("Format error in file " + JLanguageTool.getDataBroker().getFromRulesDirAsUrl(getFileName()) + ", line: " + line); } map.put(parts[0], parts[1]); } } finally { if (br != null) { br.close(); } if (isr != null) { isr.close(); } } return map; } public void reset() { } } Here is what I need the SimpleReplaceRule.java to do: 1 - Be able to have more than two spelling variations in the coherency.txt file (right now it can only be Word1;Word2). 2 - Find the first use of ANY of the spelling variations in a document that are found in coherency.txt and then make sure only that spelling is used throughout the document (ex. in the coherency.txt I have Word1;Word2;Word3 then in my document on the first line I write Word2. then on next line I write Word1 and Word 3 - then the grammar checker will flag Word1 and Word3 saying that I should use the spelling "Word2" instead...etc.). If anyone can help I would be grateful! Thanks for your time, Nathan

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  • PHP Templated site w/ file_get_content links

    - by s32ialx
    Ok so i have a template script my friend built for me. I'll include all file names OK so what is not working is file_get_contents is not grabing the content (1 I don't know where the content should be placed and 2 i want it placed in a directory so that IF i change the template the area where content stays is the same. I'm trying to get file_get_contents to load the links ?=about ?=services etc to load in to body.tpl in the contents div please any help is apperciated. /* file.class.php */ <?php $file = new file(); class file{ var $path = "templates/clean"; var $ext = "tpl"; function loadfile($filename){ return file_get_contents($this->path . "/" . $filename . "." . $this->ext); } function css($val,$content='',$contentvar='#CSS#') { if(is_array($val)) { $css = 'style="'; foreach($val as $p) { $css .= $p . ";"; } $css .= '"'; } else { $css = 'style="' . $val . '"'; } if($content!='') { return str_replace($contentvar,' ' . $css,$content); } else { return $css; } } function setsize($content,$width='-1',$height='-1',$border='-1'){ $css = ''; if($width!='-1') { $css = $css . "width=\"".$width."\""; } if($height!='-1') { $css = $css . "height=\"".$height."\""; } if($border!='-1') { $css = $css . "border=\"" . $border . "\""; } return str_replace('#SIZE#',' ' . $css,$content); } function setcontent($content,$newcontent,$vartoreplace='#CONTENT#'){ $val = str_replace($vartoreplace,$newcontent,$content); return $val; } function p($content) { $v = $content; $v = str_replace('#CONTENT#','',$v); $v = str_replace('#SIZE#','',$v); print $v; } } if (isset($_GET['page'])) { $content = $_GET['page'].'.php'; } else { $content = 'main.php'; } ?> if some one could trim that down so it JUST is the template required code and file get contents. /* index.php */ <?php include('classes/file.class.php'); //load template content $header = $file->loadfile('header'); $body = $file->loadfile('body'); $footer = $file->loadfile('footer'); //assign content to multiple variables $file->p($header . $body . $footer); ?> /* header.tpl */ <!DOCTYPE html PUBLIC "-//W3C//DTD XHTML 1.0 Transitional//EN" "http://www.w3.org/TR/xhtml1/DTD/xhtml1-Transitional.dtd"> <html xmlns="http://www.w3.org/1999/xhtml" xml:lang="en" lang="en"> <head> <meta http-equiv="Content-Type" content="text/html; charset=iso-8859-1"/> <meta name="robots" content="index,follow"/> <meta name="distribution" content="global"/> <meta name="description" content=""/> <meta name="keywords" content=""/> <link href="templates/clean/style.css" rel="stylesheet" type="text/css" media="screen" /> <link rel="stylesheet" href="templates/clean/menu_style.css" type="text/css" /> <script type="text/javascript" src="http://jqueryjs.googlecode.com/files/jquery-1.3.2.min.js"></script> </head> <body> <div id="header"> <div id="logo"><a href="index.php" style="height:30px;width:150px;"><img src="images/logo.png" border="0" alt=""/></a></div> <div id="menuo"> <div class="menu"> <ul id="menu"> <li><a href="?page=home">Home</a></li> <li><a href="?page=about">About Us</a></li> <li><a href="?page=services">Services</a> <ul> <li><a href="?page=instore">InStore Repairs</a></li> <li><a href="?page=inhome">InHome Repairs</a></li> <li><a href="?page=website">Website Design</a></li> <li><a href="?page=soon">Comming Soon.</a></li> </ul> </li> <li><a href="?page=products">Products</a> <ul> <li><a href="?page=pchard">Computer Hardware</a></li> <li><a href="?page=monitor">Monitor's</a></li> <li><a href="?page=laptop">Laptop + Netbooks</a></li> <li><a href="?page=soon">Comming Soon.</a></li> </ul> </li> <li><a href="?page=contact">Contact</a></li> </ul> </div> </div> </div> <div id="headerf"> </div> /* body.tpl */ <div id="bodys"> <div id="bodt"></div> <div id="bodm"> <div id="contents"> #CONTENT# </div> /* footer.tpl */ <div id="footer"> <div style="position:absolute; top:4px; left:4px;"><img src="images/ff.png" alt="ok"></div> <div style="position:absolute; top:4px; right:5px; color:#FFFFFF;">&copy;2010 <a href="mailto:">Company Name</a></div> </div> </body> </html>

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  • Will these optimizations to my Ruby implementation of diff improve performance in a Rails app?

    - by grg-n-sox
    <tl;dr> In source version control diff patch generation, would it be worth it to use the optimizations listed at the very bottom of this writing (see <optimizations>) in my Ruby implementation of diff for making diff patches? </tl;dr> <introduction> I am programming something I have never done before and there might already be tools out there to do the exact thing I am programming but at this point I am having too much fun to care so I am still going to do it from scratch, even if there is a tool for this. So anyways, I am working on a Ruby on Rails app and need a certain feature. Basically I want each entry in a table of mine, let's say for example a table of video games, to have a stored chunk of text that represents a review or something of the sort for that table entry. However, I want this text to be both editable by any registered user and also keep track of different submissions in a version control system. The simplest solution I could think of is just implement a solution that keeps track of the text body and the diff patch history of different versions of the text body as objects in Ruby and then serialize it, preferably in human readable form (so I'll most likely use YAML for this) for editing if needed due to corruption by a software bug or a mistake is made by an admin doing some version editing. So at first I just tried to dive in head first into this feature to find that the problem of generating a diff patch is more difficult that I thought to do efficiently. So I did some research and came across some ideas. Some I have implemented already and some I have not. However, it all pretty much revolves around the longest common subsequence problem, as you would already know if you have already done anything with diff or diff-like features, and optimization the function that solves it. Currently I have it so it truncates the compared versions of the text body from the beginning and end until non-matching lines are found. Then it solves the problem using a comparison matrix, but instead of incrementing the value stored in a cell when it finds a matching line like in most longest common subsequence algorithms I have seen examples of, I increment when I have a non-matching line so as to calculate edit distance instead of longest common subsequence. Although as far as I can tell between the two approaches, they are essentially two sides of the same coin so either could be used to derive an answer. It then back-traces through the comparison matrix and notes when there was an incrementation and in which adjacent cell (West, Northwest, or North) to determine that line's diff entry and assumes all other lines to be unchanged. Normally I would leave it at that, but since this is going into a Rails environment and not just some stand-alone Ruby script, I started getting worried about needing to optimize at least enough so if a spammer that somehow knew how I implemented the version control system and knew my worst case scenario entry still wouldn't be able to hit the server that bad. After some searching and reading of research papers and articles through the internet, I've come across several that seem decent but all seem to have pros and cons and I am having a hard time deciding how well in this situation that the pros and cons balance out. So are the ones listed here worth it? I have listed them with known pros and cons. </introduction> <optimizations> Chop the compared sequences into multiple chucks of subsequences by splitting where lines are unchanged, and then truncating each section of unchanged lines at the beginning and end of each section. Then solve the edit distance of each subsequence. Pro: Changes the time increase as the changed area gets bigger from a quadratic increase to something more similar to a linear increase. Con: Figuring out where to split already seems like you have to solve edit distance except now you don't care how it is changed. Would be fine if this was solvable by a process closer to solving hamming distance but a single insertion would throw this off. Use a cryptographic hash function to both convert all sequence elements into integers and ensure uniqueness. Then solve the edit distance comparing the hash integers instead of the sequence elements themselves. Pro: The operation of comparing two integers is faster than the operation of comparing two strings, so a slight performance gain is received after every comparison, which can be a lot overall. Con: Using a cryptographic hash function takes time to convert all the sequence elements and may end up costing more time to do the conversion that you gain back from the integer comparisons. You could use the built in hash function for a string but that will not guarantee uniqueness. Use lazy evaluation to only calculate the three center-most diagonals of the comparison matrix and then only calculate additional diagonals as needed. And then also use this approach to possibly remove the need on some comparisons to compare all three adjacent cells as desribed here. Pro: Can turn an algorithm that always takes O(n * m) time and make it so only worst case scenario is that time, best case becomes practically linear, and average case is somewhere between the two. Con: It is an algorithm I've only seen implemented in functional programming languages and I am having a difficult time comprehending how to convert this into Ruby based on how it is described at the site linked to above. Make a C module and do the hard work at the native level in C and just make a Ruby wrapper for it so Ruby can make all the calls to it that it needs. Pro: I have to imagine that evaluating something like this in could be a LOT faster. Con: I have no idea how Rails handles apps with ruby code that has C extensions and it hurts the portability of the app. This is an optimization for after the solving of edit distance, but idea is to store additional combined diffs with the ones produced by each version to make a delta-tree data structure with the most recently made diff as the root node of the tree so getting to any version takes worst case time of O(log n) instead of O(n). Pro: Would make going back to an old version a lot faster. Con: It would mean every new commit, the delta-tree would get a new root node that will cost time to reorganize the delta-tree for an operation that will be carried out a lot more often than going back a version, not to mention the unlikelihood it will be an old version. </optimizations> So are these things worth the effort?

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  • Authoritative sources about Database vs. Flatfile decision

    - by FastAl
    <tldr>looking for a reference to a book or other undeniably authoritative source that gives reasons when you should choose a database vs. when you should choose other storage methods. I have provided an un-authoritative list of reasons about 2/3 of the way down this post.</tldr> I have a situation at my company where a database is being used where it would be better to use another solution (in this case, an auto-generated piece of source code that contains a static lookup table, searched by binary sort). Normally, a database would be an OK solution even though the problem does not require a database, e.g, none of the elements of ACID are needed, as it is read-only data, updated about every 3-5 years (also requiring other sourcecode changes), and fits in memory, and can be keyed into via binary search (a tad faster than db, but speed is not an issue). The problem is that this code runs on our enterprise server, but is shared with several PC platforms (some disconnected, some use a central DB, etc.), and parts of it are managed by multiple programming units, parts by the DBAs, parts even by mathematicians in another department, etc. These hit their own platform’s version of their databases (containing their own copy of the static data). What happens is that every implementation, every little change, something different goes wrong. There are many other issues as well. I can’t even use a flatfile, because one mode of running on our enterprise server does not have permission to read files (only databases, and of course, its own literal storage, e.g., in-source table). Of course, other parts of the system use databases in proper, less obscure manners; there is no problem with those parts. So why don’t we just change it? I don’t have administrative ability to force a change. But I’m affected because sometimes I have to help fix the problems, but mostly because it causes outages and tons of extra IT time by other programmers and d*mmit that makes me mad! The reason neither management, nor the designers of the system, can see the problem is that they propose a solution that won’t work: increase communication; implement more safeguards and standards; etc. But every time, in a different part of the already-pared-down but still multi-step processes, a few different diligent, hard-working, top performing IT personnel make a unique subtle error that causes it to fail, sometimes after the last round of testing! And in general these are not single-person failures, but understandable miscommunications. And communication at our company is actually better than most. People just don't think that's the case because they haven't dug into the matter. However, I have it on very good word from somebody with extensive formal study of sociology and psychology that the relatively small amount of less-than-proper database usage in this gigantic cross-platform multi-source, multi-language project is bureaucratically un-maintainable. Impossible. No chance. At least with Human Beings in the loop, and it can’t be automated. In addition, the management and developers who could change this, though intelligent and capable, don’t understand the rigidity of this ‘how humans are’ issue, and are not convincible on the matter. The reason putting the static data in sourcecode will solve the problem is, although the solution is less sexy than a database, it would function with no technical drawbacks; and since the sharing of sourcecode already works very well, you basically erase any database-related effort from this section of the project, along with all the drawbacks of it that are causing problems. OK, that’s the background, for the curious. I won’t be able to convince management that this is an unfixable sociological problem, and that the real solution is coding around these limits of human nature, just as you would code around a bug in a 3rd party component that you can’t change. So what I have to do is exploit the unsuitableness of the database solution, and not do it using logic, but rather authority. I am aware of many reasons, and posts on this site giving reasons for one over the other; I’m not looking for lists of reasons like these (although you can add a comment if I've miss a doozy): WHY USE A DATABASE? instead of flatfile/other DB vs. file: if you need... Random Read / Transparent search optimization Advanced / varied / customizable Searching and sorting capabilities Transaction/rollback Locks, semaphores Concurrency control / Shared users Security 1-many/m-m is easier Easy modification Scalability Load Balancing Random updates / inserts / deletes Advanced query Administrative control of design, etc. SQL / learning curve Debugging / Logging Centralized / Live Backup capabilities Cached queries / dvlp & cache execution plans Interleaved update/read Referential integrity, avoid redundant/missing/corrupt/out-of-sync data Reporting (from on olap or oltp db) / turnkey generation tools [Disadvantages:] Important to get right the first time - professional design - but only b/c it's meant to last s/w & h/w cost Usu. over a network, speed issue (best vs. best design vs. local=even then a separate process req's marshalling/netwk layers/inter-p comm) indicies and query processing can stand in the way of simple processing (vs. flatfile) WHY USE FLATFILE: If you only need... Sequential Row processing only Limited usage append only (no reading, no master key/update) Only Update the record you're reading (fixed length recs only) Too big to fit into memory If Local disk / read-ahead network connection Portability / small system Email / cut & Paste / store as document by novice - simple format Low design learning curve but high cost later WHY USE IN-MEMORY/TABLE (tables, arrays, etc.): if you need... Processing a single db/ff record that was imported Known size of data Static data if hardcoding the table Narrow, unchanging use (e.g., one program or proc) -includes a class that will be shared, but encapsulates its data manipulation Extreme speed needed / high transaction frequency Random access - but search is dependent on implementation Following are some other posts about the topic: http://stackoverflow.com/questions/1499239/database-vs-flat-text-file-what-are-some-technical-reasons-for-choosing-one-over http://stackoverflow.com/questions/332825/are-flat-file-databases-any-good http://stackoverflow.com/questions/2356851/database-vs-flat-files http://stackoverflow.com/questions/514455/databases-vs-plain-text/514530 What I’d like to know is if anybody could recommend a hard, authoritative source containing these reasons. I’m looking for a paper book I can buy, or a reputable website with whitepapers about the issue (e.g., Microsoft, IBM), not counting the user-generated content on those sites. This will have a greater change to elicit a change that I’m looking for: less wasted programmer time, and more reliable programs. Thanks very much for your help. You win a prize for reading such a large post!

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  • Diving into OpenStack Network Architecture - Part 2 - Basic Use Cases

    - by Ronen Kofman
      rkofman Normal rkofman 4 138 2014-06-05T03:38:00Z 2014-06-05T05:04:00Z 3 2735 15596 Oracle Corporation 129 36 18295 12.00 Clean Clean false false false false EN-US X-NONE HE /* Style Definitions */ table.MsoNormalTable {mso-style-name:"Table Normal"; mso-tstyle-rowband-size:0; mso-tstyle-colband-size:0; mso-style-noshow:yes; mso-style-priority:99; mso-style-qformat:yes; mso-style-parent:""; mso-padding-alt:0in 5.4pt 0in 5.4pt; mso-para-margin-top:0in; mso-para-margin-right:0in; mso-para-margin-bottom:10.0pt; mso-para-margin-left:0in; line-height:115%; mso-pagination:widow-orphan; font-size:11.0pt; font-family:"Calibri","sans-serif"; mso-ascii-font-family:Calibri; mso-ascii-theme-font:minor-latin; mso-hansi-font-family:Calibri; mso-hansi-theme-font:minor-latin; mso-bidi-font-family:Arial; mso-bidi-theme-font:minor-bidi; mso-bidi-language:AR-SA;} In the previous post we reviewed several network components including Open vSwitch, Network Namespaces, Linux Bridges and veth pairs. In this post we will take three simple use cases and see how those basic components come together to create a complete SDN solution in OpenStack. With those three use cases we will review almost the entire network setup and see how all the pieces work together. The use cases we will use are: 1.       Create network – what happens when we create network and how can we create multiple isolated networks 2.       Launch a VM – once we have networks we can launch VMs and connect them to networks. 3.       DHCP request from a VM – OpenStack can automatically assign IP addresses to VMs. This is done through local DHCP service controlled by OpenStack Neutron. We will see how this service runs and how does a DHCP request and response look like. In this post we will show connectivity, we will see how packets get from point A to point B. We first focus on how a configured deployment looks like and only later we will discuss how and when the configuration is created. Personally I found it very valuable to see the actual interfaces and how they connect to each other through examples and hands on experiments. After the end game is clear and we know how the connectivity works, in a later post, we will take a step back and explain how Neutron configures the components to be able to provide such connectivity.  We are going to get pretty technical shortly and I recommend trying these examples on your own deployment or using the Oracle OpenStack Tech Preview. Understanding these three use cases thoroughly and how to look at them will be very helpful when trying to debug a deployment in case something does not work. Use case #1: Create Network Create network is a simple operation it can be performed from the GUI or command line. When we create a network in OpenStack the network is only available to the tenant who created it or it could be defined as “shared” and then it can be used by all tenants. A network can have multiple subnets but for this demonstration purpose and for simplicity we will assume that each network has exactly one subnet. Creating a network from the command line will look like this: # neutron net-create net1 Created a new network: +---------------------------+--------------------------------------+ | Field                     | Value                                | +---------------------------+--------------------------------------+ | admin_state_up            | True                                 | | id                        | 5f833617-6179-4797-b7c0-7d420d84040c | | name                      | net1                                 | | provider:network_type     | vlan                                 | | provider:physical_network | default                              | | provider:segmentation_id  | 1000                                 | | shared                    | False                                | | status                    | ACTIVE                               | | subnets                   |                                      | | tenant_id                 | 9796e5145ee546508939cd49ad59d51f     | +---------------------------+--------------------------------------+ Creating a subnet for this network will look like this: # neutron subnet-create net1 10.10.10.0/24 Created a new subnet: +------------------+------------------------------------------------+ | Field            | Value                                          | +------------------+------------------------------------------------+ | allocation_pools | {"start": "10.10.10.2", "end": "10.10.10.254"} | | cidr             | 10.10.10.0/24                                  | | dns_nameservers  |                                                | | enable_dhcp      | True                                           | | gateway_ip       | 10.10.10.1                                     | | host_routes      |                                                | | id               | 2d7a0a58-0674-439a-ad23-d6471aaae9bc           | | ip_version       | 4                                              | | name             |                                                | | network_id       | 5f833617-6179-4797-b7c0-7d420d84040c           | | tenant_id        | 9796e5145ee546508939cd49ad59d51f               | +------------------+------------------------------------------------+ We now have a network and a subnet, on the network topology view this looks like this: Now let’s dive in and see what happened under the hood. Looking at the control node we will discover that a new namespace was created: # ip netns list qdhcp-5f833617-6179-4797-b7c0-7d420d84040c   The name of the namespace is qdhcp-<network id> (see above), let’s look into the namespace and see what’s in it: # ip netns exec qdhcp-5f833617-6179-4797-b7c0-7d420d84040c ip addr 1: lo: <LOOPBACK,UP,LOWER_UP> mtu 65536 qdisc noqueue state UNKNOWN     link/loopback 00:00:00:00:00:00 brd 00:00:00:00:00:00     inet 127.0.0.1/8 scope host lo     inet6 ::1/128 scope host        valid_lft forever preferred_lft forever 12: tap26c9b807-7c: <BROADCAST,UP,LOWER_UP> mtu 1500 qdisc noqueue state UNKNOWN     link/ether fa:16:3e:1d:5c:81 brd ff:ff:ff:ff:ff:ff     inet 10.10.10.3/24 brd 10.10.10.255 scope global tap26c9b807-7c     inet6 fe80::f816:3eff:fe1d:5c81/64 scope link        valid_lft forever preferred_lft forever   We see two interfaces in the namespace, one is the loopback and the other one is an interface called “tap26c9b807-7c”. This interface has the IP address of 10.10.10.3 and it will also serve dhcp requests in a way we will see later. Let’s trace the connectivity of the “tap26c9b807-7c” interface from the namespace.  First stop is OVS, we see that the interface connects to bridge  “br-int” on OVS: # ovs-vsctl show 8a069c7c-ea05-4375-93e2-b9fc9e4b3ca1     Bridge "br-eth2"         Port "br-eth2"             Interface "br-eth2"                 type: internal         Port "eth2"             Interface "eth2"         Port "phy-br-eth2"             Interface "phy-br-eth2"     Bridge br-ex         Port br-ex             Interface br-ex                 type: internal     Bridge br-int         Port "int-br-eth2"             Interface "int-br-eth2"         Port "tap26c9b807-7c"             tag: 1             Interface "tap26c9b807-7c"                 type: internal         Port br-int             Interface br-int                 type: internal     ovs_version: "1.11.0"   In the picture above we have a veth pair which has two ends called “int-br-eth2” and "phy-br-eth2", this veth pair is used to connect two bridge in OVS "br-eth2" and "br-int". In the previous post we explained how to check the veth connectivity using the ethtool command. It shows that the two are indeed a pair: # ethtool -S int-br-eth2 NIC statistics:      peer_ifindex: 10 . .   #ip link . . 10: phy-br-eth2: <BROADCAST,MULTICAST,UP,LOWER_UP> mtu 1500 qdisc pfifo_fast state UP qlen 1000 . . Note that “phy-br-eth2” is connected to a bridge called "br-eth2" and one of this bridge's interfaces is the physical link eth2. This means that the network which we have just created has created a namespace which is connected to the physical interface eth2. eth2 is the “VM network” the physical interface where all the virtual machines connect to where all the VMs are connected. About network isolation: OpenStack supports creation of multiple isolated networks and can use several mechanisms to isolate the networks from one another. The isolation mechanism can be VLANs, VxLANs or GRE tunnels, this is configured as part of the initial setup in our deployment we use VLANs. When using VLAN tagging as an isolation mechanism a VLAN tag is allocated by Neutron from a pre-defined VLAN tags pool and assigned to the newly created network. By provisioning VLAN tags to the networks Neutron allows creation of multiple isolated networks on the same physical link.  The big difference between this and other platforms is that the user does not have to deal with allocating and managing VLANs to networks. The VLAN allocation and provisioning is handled by Neutron which keeps track of the VLAN tags, and responsible for allocating and reclaiming VLAN tags. In the example above net1 has the VLAN tag 1000, this means that whenever a VM is created and connected to this network the packets from that VM will have to be tagged with VLAN tag 1000 to go on this particular network. This is true for namespace as well, if we would like to connect a namespace to a particular network we have to make sure that the packets to and from the namespace are correctly tagged when they reach the VM network. In the example above we see that the namespace interface “tap26c9b807-7c” has vlan tag 1 assigned to it, if we examine OVS we see that it has flows which modify VLAN tag 1 to VLAN tag 1000 when a packet goes to the VM network on eth2 and vice versa. We can see this using the dump-flows command on OVS for packets going to the VM network we see the modification done on br-eth2: #  ovs-ofctl dump-flows br-eth2 NXST_FLOW reply (xid=0x4):  cookie=0x0, duration=18669.401s, table=0, n_packets=857, n_bytes=163350, idle_age=25, priority=4,in_port=2,dl_vlan=1 actions=mod_vlan_vid:1000,NORMAL  cookie=0x0, duration=165108.226s, table=0, n_packets=14, n_bytes=1000, idle_age=5343, hard_age=65534, priority=2,in_port=2 actions=drop  cookie=0x0, duration=165109.813s, table=0, n_packets=1671, n_bytes=213304, idle_age=25, hard_age=65534, priority=1 actions=NORMAL   For packets coming from the interface to the namespace we see the following modification: #  ovs-ofctl dump-flows br-int NXST_FLOW reply (xid=0x4):  cookie=0x0, duration=18690.876s, table=0, n_packets=1610, n_bytes=210752, idle_age=1, priority=3,in_port=1,dl_vlan=1000 actions=mod_vlan_vid:1,NORMAL  cookie=0x0, duration=165130.01s, table=0, n_packets=75, n_bytes=3686, idle_age=4212, hard_age=65534, priority=2,in_port=1 actions=drop  cookie=0x0, duration=165131.96s, table=0, n_packets=863, n_bytes=160727, idle_age=1, hard_age=65534, priority=1 actions=NORMAL   To summarize we can see that when a user creates a network Neutron creates a namespace and this namespace is connected through OVS to the “VM network”. OVS also takes care of tagging the packets from the namespace to the VM network with the correct VLAN tag and knows to modify the VLAN for packets coming from VM network to the namespace. Now let’s see what happens when a VM is launched and how it is connected to the “VM network”. Use case #2: Launch a VM Launching a VM can be done from Horizon or from the command line this is how we do it from Horizon: Attach the network: And Launch Once the virtual machine is up and running we can see the associated IP using the nova list command : # nova list +--------------------------------------+--------------+--------+------------+-------------+-----------------+ | ID                                   | Name         | Status | Task State | Power State | Networks        | +--------------------------------------+--------------+--------+------------+-------------+-----------------+ | 3707ac87-4f5d-4349-b7ed-3a673f55e5e1 | Oracle Linux | ACTIVE | None       | Running     | net1=10.10.10.2 | +--------------------------------------+--------------+--------+------------+-------------+-----------------+ The nova list command shows us that the VM is running and that the IP 10.10.10.2 is assigned to this VM. Let’s trace the connectivity from the VM to VM network on eth2 starting with the VM definition file. The configuration files of the VM including the virtual disk(s), in case of ephemeral storage, are stored on the compute node at/var/lib/nova/instances/<instance-id>/. Looking into the VM definition file ,libvirt.xml,  we see that the VM is connected to an interface called “tap53903a95-82” which is connected to a Linux bridge called “qbr53903a95-82”: <interface type="bridge">       <mac address="fa:16:3e:fe:c7:87"/>       <source bridge="qbr53903a95-82"/>       <target dev="tap53903a95-82"/>     </interface>   Looking at the bridge using the brctl show command we see this: # brctl show bridge name     bridge id               STP enabled     interfaces qbr53903a95-82          8000.7e7f3282b836       no              qvb53903a95-82                                                         tap53903a95-82    The bridge has two interfaces, one connected to the VM (“tap53903a95-82 “) and another one ( “qvb53903a95-82”) connected to “br-int” bridge on OVS: # ovs-vsctl show 83c42f80-77e9-46c8-8560-7697d76de51c     Bridge "br-eth2"         Port "br-eth2"             Interface "br-eth2"                 type: internal         Port "eth2"             Interface "eth2"         Port "phy-br-eth2"             Interface "phy-br-eth2"     Bridge br-int         Port br-int             Interface br-int                 type: internal         Port "int-br-eth2"             Interface "int-br-eth2"         Port "qvo53903a95-82"             tag: 3             Interface "qvo53903a95-82"     ovs_version: "1.11.0"   As we showed earlier “br-int” is connected to “br-eth2” on OVS using the veth pair int-br-eth2,phy-br-eth2 and br-eth2 is connected to the physical interface eth2. The whole flow end to end looks like this: VM è tap53903a95-82 (virtual interface)è qbr53903a95-82 (Linux bridge) è qvb53903a95-82 (interface connected from Linux bridge to OVS bridge br-int) è int-br-eth2 (veth one end) è phy-br-eth2 (veth the other end) è eth2 physical interface. The purpose of the Linux Bridge connecting to the VM is to allow security group enforcement with iptables. Security groups are enforced at the edge point which are the interface of the VM, since iptables nnot be applied to OVS bridges we use Linux bridge to apply them. In the future we hope to see this Linux Bridge going away rules.  VLAN tags: As we discussed in the first use case net1 is using VLAN tag 1000, looking at OVS above we see that qvo41f1ebcf-7c is tagged with VLAN tag 3. The modification from VLAN tag 3 to 1000 as we go to the physical network is done by OVS  as part of the packet flow of br-eth2 in the same way we showed before. To summarize, when a VM is launched it is connected to the VM network through a chain of elements as described here. During the packet from VM to the network and back the VLAN tag is modified. Use case #3: Serving a DHCP request coming from the virtual machine In the previous use cases we have shown that both the namespace called dhcp-<some id> and the VM end up connecting to the physical interface eth2  on their respective nodes, both will tag their packets with VLAN tag 1000.We saw that the namespace has an interface with IP of 10.10.10.3. Since the VM and the namespace are connected to each other and have interfaces on the same subnet they can ping each other, in this picture we see a ping from the VM which was assigned 10.10.10.2 to the namespace: The fact that they are connected and can ping each other can become very handy when something doesn’t work right and we need to isolate the problem. In such case knowing that we should be able to ping from the VM to the namespace and back can be used to trace the disconnect using tcpdump or other monitoring tools. To serve DHCP requests coming from VMs on the network Neutron uses a Linux tool called “dnsmasq”,this is a lightweight DNS and DHCP service you can read more about it here. If we look at the dnsmasq on the control node with the ps command we see this: dnsmasq --no-hosts --no-resolv --strict-order --bind-interfaces --interface=tap26c9b807-7c --except-interface=lo --pid-file=/var/lib/neutron/dhcp/5f833617-6179-4797-b7c0-7d420d84040c/pid --dhcp-hostsfile=/var/lib/neutron/dhcp/5f833617-6179-4797-b7c0-7d420d84040c/host --dhcp-optsfile=/var/lib/neutron/dhcp/5f833617-6179-4797-b7c0-7d420d84040c/opts --leasefile-ro --dhcp-range=tag0,10.10.10.0,static,120s --dhcp-lease-max=256 --conf-file= --domain=openstacklocal The service connects to the tap interface in the namespace (“--interface=tap26c9b807-7c”), If we look at the hosts file we see this: # cat  /var/lib/neutron/dhcp/5f833617-6179-4797-b7c0-7d420d84040c/host fa:16:3e:fe:c7:87,host-10-10-10-2.openstacklocal,10.10.10.2   If you look at the console output above you can see the MAC address fa:16:3e:fe:c7:87 which is the VM MAC. This MAC address is mapped to IP 10.10.10.2 and so when a DHCP request comes with this MAC dnsmasq will return the 10.10.10.2.If we look into the namespace at the time we initiate a DHCP request from the VM (this can be done by simply restarting the network service in the VM) we see the following: # ip netns exec qdhcp-5f833617-6179-4797-b7c0-7d420d84040c tcpdump -n 19:27:12.191280 IP 0.0.0.0.bootpc > 255.255.255.255.bootps: BOOTP/DHCP, Request from fa:16:3e:fe:c7:87, length 310 19:27:12.191666 IP 10.10.10.3.bootps > 10.10.10.2.bootpc: BOOTP/DHCP, Reply, length 325   To summarize, the DHCP service is handled by dnsmasq which is configured by Neutron to listen to the interface in the DHCP namespace. Neutron also configures dnsmasq with the combination of MAC and IP so when a DHCP request comes along it will receive the assigned IP. Summary In this post we relied on the components described in the previous post and saw how network connectivity is achieved using three simple use cases. These use cases gave a good view of the entire network stack and helped understand how an end to end connection is being made between a VM on a compute node and the DHCP namespace on the control node. One conclusion we can draw from what we saw here is that if we launch a VM and it is able to perform a DHCP request and receive a correct IP then there is reason to believe that the network is working as expected. We saw that a packet has to travel through a long list of components before reaching its destination and if it has done so successfully this means that many components are functioning properly. In the next post we will look at some more sophisticated services Neutron supports and see how they work. We will see that while there are some more components involved for the most part the concepts are the same. @RonenKofman

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  • How do I prove I should put a table of values in source code instead of a database table?

    - by FastAl
    <tldr>looking for a reference to a book or other undeniably authoritative source that gives reasons when you should choose a database vs. when you should choose other storage methods. I have provided an un-authoritative list of reasons about 2/3 of the way down this post.</tldr> I have a situation at my company where a database is being used where it would be better to use another solution (in this case, an auto-generated piece of source code that contains a static lookup table, searched by binary sort). Normally, a database would be an OK solution even though the problem does not require a database, e.g, none of the elements of ACID are needed, as it is read-only data, updated about every 3-5 years (also requiring other sourcecode changes), and fits in memory, and can be keyed into via binary search (a tad faster than db, but speed is not an issue). The problem is that this code runs on our enterprise server, but is shared with several PC platforms (some disconnected, some use a central DB, etc.), and parts of it are managed by multiple programming units, parts by the DBAs, parts even by mathematicians in another department, etc. These hit their own platform’s version of their databases (containing their own copy of the static data). What happens is that every implementation, every little change, something different goes wrong. There are many other issues as well. I can’t even use a flatfile, because one mode of running on our enterprise server does not have permission to read files (only databases, and of course, its own literal storage, e.g., in-source table). Of course, other parts of the system use databases in proper, less obscure manners; there is no problem with those parts. So why don’t we just change it? I don’t have administrative ability to force a change. But I’m affected because sometimes I have to help fix the problems, but mostly because it causes outages and tons of extra IT time by other programmers and d*mmit that makes me mad! The reason neither management, nor the designers of the system, can see the problem is that they propose a solution that won’t work: increase communication; implement more safeguards and standards; etc. But every time, in a different part of the already-pared-down but still multi-step processes, a few different diligent, hard-working, top performing IT personnel make a unique subtle error that causes it to fail, sometimes after the last round of testing! And in general these are not single-person failures, but understandable miscommunications. And communication at our company is actually better than most. People just don't think that's the case because they haven't dug into the matter. However, I have it on very good word from somebody with extensive formal study of sociology and psychology that the relatively small amount of less-than-proper database usage in this gigantic cross-platform multi-source, multi-language project is bureaucratically un-maintainable. Impossible. No chance. At least with Human Beings in the loop, and it can’t be automated. In addition, the management and developers who could change this, though intelligent and capable, don’t understand the rigidity of this ‘how humans are’ issue, and are not convincible on the matter. The reason putting the static data in sourcecode will solve the problem is, although the solution is less sexy than a database, it would function with no technical drawbacks; and since the sharing of sourcecode already works very well, you basically erase any database-related effort from this section of the project, along with all the drawbacks of it that are causing problems. OK, that’s the background, for the curious. I won’t be able to convince management that this is an unfixable sociological problem, and that the real solution is coding around these limits of human nature, just as you would code around a bug in a 3rd party component that you can’t change. So what I have to do is exploit the unsuitableness of the database solution, and not do it using logic, but rather authority. I am aware of many reasons, and posts on this site giving reasons for one over the other; I’m not looking for lists of reasons like these (although you can add a comment if I've miss a doozy): WHY USE A DATABASE? instead of flatfile/other DB vs. file: if you need... Random Read / Transparent search optimization Advanced / varied / customizable Searching and sorting capabilities Transaction/rollback Locks, semaphores Concurrency control / Shared users Security 1-many/m-m is easier Easy modification Scalability Load Balancing Random updates / inserts / deletes Advanced query Administrative control of design, etc. SQL / learning curve Debugging / Logging Centralized / Live Backup capabilities Cached queries / dvlp & cache execution plans Interleaved update/read Referential integrity, avoid redundant/missing/corrupt/out-of-sync data Reporting (from on olap or oltp db) / turnkey generation tools [Disadvantages:] Important to get right the first time - professional design - but only b/c it's meant to last s/w & h/w cost Usu. over a network, speed issue (best vs. best design vs. local=even then a separate process req's marshalling/netwk layers/inter-p comm) indicies and query processing can stand in the way of simple processing (vs. flatfile) WHY USE FLATFILE: If you only need... Sequential Row processing only Limited usage append only (no reading, no master key/update) Only Update the record you're reading (fixed length recs only) Too big to fit into memory If Local disk / read-ahead network connection Portability / small system Email / cut & Paste / store as document by novice - simple format Low design learning curve but high cost later WHY USE IN-MEMORY/TABLE (tables, arrays, etc.): if you need... Processing a single db/ff record that was imported Known size of data Static data if hardcoding the table Narrow, unchanging use (e.g., one program or proc) -includes a class that will be shared, but encapsulates its data manipulation Extreme speed needed / high transaction frequency Random access - but search is dependent on implementation Following are some other posts about the topic: http://stackoverflow.com/questions/1499239/database-vs-flat-text-file-what-are-some-technical-reasons-for-choosing-one-over http://stackoverflow.com/questions/332825/are-flat-file-databases-any-good http://stackoverflow.com/questions/2356851/database-vs-flat-files http://stackoverflow.com/questions/514455/databases-vs-plain-text/514530 What I’d like to know is if anybody could recommend a hard, authoritative source containing these reasons. I’m looking for a paper book I can buy, or a reputable website with whitepapers about the issue (e.g., Microsoft, IBM), not counting the user-generated content on those sites. This will have a greater change to elicit a change that I’m looking for: less wasted programmer time, and more reliable programs. Thanks very much for your help. You win a prize for reading such a large post!

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  • How to find an entry-level job after you already have a graduate degree?

    - by Uri
    Note: I asked this question in early 2009. A couple of months later, I found a great job. I've previously updated this question with some tips for whoever ends up in a similar situation, and now cleaned it up a little for the benefit of the fresh batch of graduates. Original post: In my early 20s I abandoned a great C++ development career path in a major company to go to graduate school and get a research masters (3 years). I did another year in industrial research, and then moved to the US to attend graduate school again, getting another masters and a Ph.D in software engineering from a top school (another 6 years down the drain). I was coding the whole way throughout my degrees (core Java and Eclipse plug-ins) and working on research related to software engineering (usability of APIs). I ended up graduating the year of the recession, with a son on the way and the prospects of no healthcare. Academic jobs and industrial research jobs are quite scarce. Initially, I was naive, thinking that with my background, I could easily find a coding job. Big mistake. It turns out that I'm in a complicated position. Entry level positions are usually offered to college undergraduates. I attended my school's career fairs, but you could immediately see signs of Ph.D. aversion and overqualification issues. Some of the recruiters I spoke with explicitly told me that they wanted 20 year olds with clean slates, and some were looking for interns since they are in various forms of hiring freezes. I managed to get a couple of interviews from these career fairs and through recruiters. However, since I've been out of school for a long time and programming primarily in Java, I am also no longer proficient in C/C++ and the usual range of college-level interview questions that everyone uses. I had no problems with this when I was 19 and interviewing for my first job since a lot of what you do in C is manipulate pointers and I was coding C++ for fun and for school. Later I was routinely doing pointer manipulation on the job, and during my first masters taught college courses with data structures and C++. But even though I remember many properties of C++ well, it's been close to ten years since I regularly used C++ and pointers. As a Java developer I rarely had to work at this level, but experience in OOD and in writing good maintainable code is meaningless for C++ interviews. Reading books as a refresh and looking at sample code did not do the trick. I also looked at mid-to-senior level Java positions, but most of them focused on J2EE APIs rather than on core Java and required a certain number of years in industrial positions. Coding research tools and prior C++ experience doesn't count. So that sends me back to entry-level jobs that are posted through job-boards, and these are not common (mostly they are Monster junk), and small companies are even less likely to answer a Ph.D. compared to the giants who participate in top-10 career fairs. Even worse, in many companies initial screening is done by HR folks who really don't want to deal with anything anomalous like a Ph.D. Any tips on how I should approach this intractable position? For example, what should I write in cover letters? Note that while immigration is not an issue for me, I cannot go freelance as I need the benefits (and in particular group health insurance). During my studies I had no time to contribute to open-source projects or maintain a popular blog, so even if I invested in that now there would be no immediate benefit. Updates: In the two months after posting this I received several offers to work as a core Java developer in the financial industry and accepted one from a firm where I am working to this day. For those who find themselves in similar situations, here are my tips: Give up on trying to find an entry level positions. You can't undo time. Accept the fact that there is Ph.D. discrimination in the job market (some might say rightfully so). It is legal to discriminate based on education. No point fighting it. The most important tip is to focus on the language you are comfortable with. The sad truth about programming in a particular language is that it is not like riding a bike. If you haven't used a language in the last few years, and can't actually apply it routinely (not just as a refresher) before you start your search, it is going to be very difficult to do well in an interview. Now that I'm interviewing others, I routinely see it in folks with a mixed C++/Java background. We maintain "a shadow" of the old language but end up with a weird mix that makes it hard to interview on either. Entry-level folks are at an advantage here since they usually have one language. Memory can help you do great in a screening interview, but without recent day-to-day experience, code tests will be difficult. Despite the supposed relation, core Java programming and J2EE programming are two different things with different skillsets. If you come from academia, you likely have very little J2EE experience and may find it hard to get accepted for a J2EE job. J2EE jobs seem to have a larger list of acronyms in their requirements. In addition, from interviewing J2EE developers it seems that for many there is a focus on mastering specific APIs and architectures, whereas core Java development tends to be secondary. In the same way that I can no longer manipulate pointers well, a J2EE developer may have difficulties doing low level Java manipulation. This puts you at a relative advantage in competing for core Java jobs! If you are able to work for startups (in terms of family life and stability) or migrate to startup-rich areas such as the west coast, you can find many exciting opportunities where advanced degrees are a benefit. I've since been approached by several startups, although I had to decline. Work through a recruiter if possible. They have direct contacts with the hiring parties, allowing you to "stand out". It is better to get a clear yes/no confirmation from a recruiter on whether a company might be interested in interviewing you, than it is to send your resume and hope that someone will ever see it. Recruiters are also a great way of bypassing HR. However, also beware of recruiters. They have a vested interest and will go to various shady practices and pressure tactics. To find a good recruiter, talk to a friend who declined a job offer he got through a recruiter. A good recruiter, to me, is measured in how they handle that. Interview for the jobs that require your core strength. If you're rusty or entirely unfamiliar with a technology around which the job revolves, you're probably not a good match. Yes, you probably have the talent to master them, but most companies would want "instant gratification". I got my offers from companies that wanted core Java developer. I didn't do well on places that wanted advance C++ because I am too rusty and not up to date on recent libraries. I also didn't hear from companies that wanted lots of J2EE experience, and that's ok. Finding companies that want core Java without web is harder, but exists in specific industries (e.g., finance, defense). This requires a lot more legwork in terms of search, but these jobs do exist. There are different interview styles. Some companies focus on puzzles, some companies focus on algorithms, and some companies focus on design and coding skills. I had the most success in places where the questions were the most related to the function I would have been performing. Pick companies accordingly as well.

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  • Drupal Ctools Form Wizard in a Block

    - by Iamjon
    Hi everyone I created a custom module that has a Ctools multi step form. It's basically a copy of http://www.nicklewis.org/using-chaos-tools-form-wizard-build-multistep-forms-drupal-6. The form works. I can see it if I got to the url i made for it. For the life of me I can't get the multistep form to show up in a block. Any clues? /** * Implementation of hook_block() * */ function mycrazymodule_block($op='list', $delta=0, $edit=array()) { switch ($op) { case 'list': $blocks[0]['info'] = t('SFT Getting Started'); $blocks[1]['info'] = t('SFT Contact US'); $blocks[2]['info'] = t('SFT News Letter'); return $blocks; case 'view': switch ($delta){ case '0': $block['subject'] = t('SFT Getting Started Subject'); $block['content'] = mycrazymodule_wizard(); break; case '1': $block['subject'] = t('SFT Contact US Subject'); $block['content'] = t('SFT Contact US content'); break; case '2': $block['subject'] = t('SFT News Letter Subject'); $block['content'] = t('SFT News Letter cONTENT'); break; } return $block; } } /** * Implementation of hook_menu(). */ function mycrazymodule_menu() { $items['hellocowboy'] = array( 'title' = 'Two Step Form', 'page callback' = 'mycrazymodule_wizard', 'access arguments' = array('access content') ); return $items; } /** * menu callback for the multistep form * step is whatever arg one is -- and will refer to the keys listed in * $form_info['order'], and $form_info['forms'] arrays */ function mycrazymodule_wizard() { $step = arg(1); // required includes for wizard $form_state = array(); ctools_include('wizard'); ctools_include('object-cache'); // The array that will hold the two forms and their options $form_info = array( 'id' = 'getting_started', 'path' = "hellocowboy/%step", 'show trail' = FALSE, 'show back' = FALSE, 'show cancel' = false, 'show return' =false, 'next text' = 'Submit', 'next callback' = 'getting_started_add_subtask_next', 'finish callback' = 'getting_started_add_subtask_finish', 'return callback' = 'getting_started_add_subtask_finish', 'order' = array( 'basic' = t('Step 1: Basic Info'), 'lecture' = t('Step 2: Choose Lecture'), ), 'forms' = array( 'basic' = array( 'form id' = 'basic_info_form' ), 'lecture' = array( 'form id' = 'choose_lecture_form' ), ), ); $form_state = array( 'cache name' = NULL, ); // no matter the step, you will load your values from the callback page $getstart = getting_started_get_page_cache(NULL); if (!$getstart) { // set form to first step -- we have no data $step = current(array_keys($form_info['order'])); $getstart = new stdClass(); //create cache ctools_object_cache_set('getting_started', $form_state['cache name'], $getstart); //print_r($getstart); } //THIS IS WHERE WILL STORE ALL FORM DATA $form_state['getting_started_obj'] = $getstart; // and this is the witchcraft that makes it work $output = ctools_wizard_multistep_form($form_info, $step, $form_state); return $output; } function basic_info_form(&$form, &$form_state){ $getstart = &$form_state['getting_started_obj']; $form['firstname'] = array( '#weight' = '0', '#type' = 'textfield', '#title' = t('firstname'), '#size' = 60, '#maxlength' = 255, '#required' = TRUE, ); $form['lastname'] = array( '#weight' = '1', '#type' = 'textfield', '#title' = t('lastname'), '#required' = TRUE, '#size' = 60, '#maxlength' = 255, ); $form['phone'] = array( '#weight' = '2', '#type' = 'textfield', '#title' = t('phone'), '#required' = TRUE, '#size' = 60, '#maxlength' = 255, ); $form['email'] = array( '#weight' = '3', '#type' = 'textfield', '#title' = t('email'), '#required' = TRUE, '#size' = 60, '#maxlength' = 255, ); $form['newsletter'] = array( '#weight' = '4', '#type' = 'checkbox', '#title' = t('I would like to receive the newsletter'), '#required' = TRUE, '#return_value' = 1, '#default_value' = 1, ); $form_state['no buttons'] = TRUE; } function basic_info_form_validate(&$form, &$form_state){ $email = $form_state['values']['email']; $phone = $form_state['values']['phone']; if(valid_email_address($email) != TRUE){ form_set_error('Dude you have an error', t('Where is your email?')); } //if (strlen($phone) 0 && !ereg('^[0-9]{1,3}-[0-9]{3}-[0-9]{3,4}-[0-9]{3,4}$', $phone)) { //form_set_error('Dude the phone', t('Phone number must be in format xxx-xxx-nnnn-nnnn.')); //} } function basic_info_form_submit(&$form, &$form_state){ //Grab the variables $firstname =check_plain ($form_state['values']['firstname']); $lastname = check_plain ($form_state['values']['lastname']); $email = check_plain ($form_state['values']['email']); $phone = check_plain ($form_state['values']['phone']); $newsletter = $form_state['values']['newsletter']; //Send the form and Grab the lead id $leadid = send_first_form($lastname, $firstname, $email,$phone, $newsletter); //Put into form $form_state['getting_started_obj']-firstname = $firstname; $form_state['getting_started_obj']-lastname = $lastname; $form_state['getting_started_obj']-email = $email; $form_state['getting_started_obj']-phone = $phone; $form_state['getting_started_obj']-newsletter = $newsletter; $form_state['getting_started_obj']-leadid = $leadid; } function choose_lecture_form(&$form, &$form_state){ $one = 'event 1' $two = 'event 2' $three = 'event 3' $getstart = &$form_state['getting_started_obj']; $form['lecture'] = array( '#weight' = '5', '#default_value' = 'two', '#options' = array( 'one' = $one, 'two' = $two, 'three' = $three, ), '#type' = 'radios', '#title' = t('Select Workshop'), '#required' = TRUE, ); $form['attendees'] = array( '#weight' = '6', '#default_value' = 'one', '#options' = array( 'one' = t('I will be arriving alone'), 'two' =t('I will be arriving with a guest'), ), '#type' = 'radios', '#title' = t('Attendees'), '#required' = TRUE, ); $form_state['no buttons'] = TRUE; } /** * Same idea as previous steps submit * */ function choose_lecture_form_submit(&$form, &$form_state) { $workshop = $form_state['values']['lecture']; $leadid = $form_state['getting_started_obj']-leadid; $attendees = $form_state['values']['attendees']; $form_state['getting_started_obj']-lecture = $workshop; $form_state['getting_started_obj']-attendees = $attendees; send_second_form($workshop, $attendees, $leadid); } /*----PART 3 CTOOLS CALLBACKS -- these usually don't have to be very unique ---------------------- */ /** * Callback generated when the add page process is finished. * this is where you'd normally save. */ function getting_started_add_subtask_finish(&$form_state) { dpm($form_state); $getstart = &$form_state['getting_started_obj']; drupal_set_message('mycrazymodule '.$getstart-name.' successfully deployed' ); //Get id // Clear the cache ctools_object_cache_clear('getting_started', $form_state['cache name']); $form_state['redirect'] = 'hellocowboy'; } /** * Callback for the proceed step * */ function getting_started_add_subtask_next(&$form_state) { dpm($form_state); $getstart = &$form_state['getting_started_obj']; $cache = ctools_object_cache_set('getting_started', $form_state['cache name'], $getstart); } /*----PART 4 CTOOLS FORM STORAGE HANDLERS -- these usually don't have to be very unique ---------------------- */ /** * Remove an item from the object cache. */ function getting_started_clear_page_cache($name) { ctools_object_cache_clear('getting_started', $name); } /** * Get the cached changes to a given task handler. */ function getting_started_get_page_cache($name) { $cache = ctools_object_cache_get('getting_started', $name); return $cache; } //Salesforce Functions function send_first_form($lastname, $firstname,$email,$phone, $newsletter){ $send = array("LastName" = $lastname , "FirstName" = $firstname, "Email" = $email ,"Phone" = $phone , "Newsletter__c" =$newsletter ); $sf = salesforce_api_connect(); $response = $sf-client-create(array($send), 'Lead'); dpm($response); return $response-id; } function send_second_form($workshop, $attendees, $leadid){ $send = array("Id" = $leadid , "Number_Of_Pepole__c" = "2" ); $sf = salesforce_api_connect(); $response = $sf-client-update(array($send), 'Lead'); dpm($response, 'the final response'); return $response-id; }

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  • need prefuse graph edges like arrows

    - by merve
    Hello, I did my homework and searched both google for a sample and a topic that is answered before on stackoverflow. But nothing has been found. My problem is ordinary edges who does not have a view like arrows. Here is what i do to hope there is forward arrows from target to destination: LabelRenderer nameLabel = new LabelRenderer("name"); nameLabel.setRoundedCorner(8, 8); DefaultRendererFactory rendererFactory = new DefaultRendererFactory(nameLabel); EdgeRenderer edgeRenderer; edgeRenderer = new EdgeRenderer(prefuse.Constants.EDGE_TYPE_LINE, prefuse.Constants.EDGE_ARROW_FORWARD); rendererFactory.setDefaultEdgeRenderer(edgeRenderer); vis.setRendererFactory(rendererFactory); Here is what i see about colour of edges, hoping these must not be transparent: int[] palette = new int[]{ColorLib.rgb(255, 180, 180), ColorLib.rgb(190, 190, 255)}; DataColorAction fill = new DataColorAction("socialnet.nodes", "gender", Constants.NOMINAL, VisualItem.FILLCOLOR, palette); ColorAction text = new ColorAction("socialnet.nodes", VisualItem.TEXTCOLOR, ColorLib.gray(0)); ColorAction edges = new ColorAction("socialnet.edges", VisualItem.STROKECOLOR, ColorLib.gray(200)); ColorAction arrow = new ColorAction("socialnet.edges", VisualItem.FILLCOLOR, ColorLib.gray(200)); ActionList colour = new ActionList(); colour.add(fill); colour.add(text); colour.add(edges); colour.add(arrow); vis.putAction("colour", colour); Thus, i wonder where am i wrong? Why my edges do not seem like arrows? Thanks for any idea. For more detail, i want to paste all of the code: /* * To change this template, choose Tools | Templates * and open the template in the editor. */ package prefusedeneme; import javax.swing.JFrame; import prefuse.data.*; import prefuse.data.io.*; import prefuse.Display; import prefuse.Visualization; import prefuse.render.*; import prefuse.util.*; import prefuse.action.assignment.*; import prefuse.Constants; import prefuse.visual.*; import prefuse.action.*; import prefuse.activity.*; import prefuse.action.layout.graph.*; import prefuse.controls.*; import prefuse.data.expression.Predicate; import prefuse.data.expression.parser.ExpressionParser; public class SocialNetworkVis { public static void main(String argv[]) { // 1. Load the data Graph graph = null; /* graph will contain the core data */ try { graph = new GraphMLReader().readGraph("socialnet.xml"); /* load the data from an XML file */ } catch (DataIOException e) { e.printStackTrace(); System.err.println("Error loading graph. Exiting..."); System.exit(1); } // 2. prepare the visualization Visualization vis = new Visualization(); /* vis is the main object that will run the visualization */ vis.add("socialnet", graph); /* add our data to the visualization */ // 3. setup the renderers and the render factory // labels for name LabelRenderer nameLabel = new LabelRenderer("name"); nameLabel.setRoundedCorner(8, 8); /* nameLabel decribes how to draw the data elements labeled as "name" */ // create the render factory DefaultRendererFactory rendererFactory = new DefaultRendererFactory(nameLabel); EdgeRenderer edgeRenderer; edgeRenderer = new EdgeRenderer(prefuse.Constants.EDGE_TYPE_LINE, prefuse.Constants.EDGE_ARROW_FORWARD); rendererFactory.setDefaultEdgeRenderer(edgeRenderer); vis.setRendererFactory(rendererFactory); // 4. process the actions // colour palette for nominal data type int[] palette = new int[]{ColorLib.rgb(255, 180, 180), ColorLib.rgb(190, 190, 255)}; /* ColorLib.rgb converts the colour values to integers */ // map data to colours in the palette DataColorAction fill = new DataColorAction("socialnet.nodes", "gender", Constants.NOMINAL, VisualItem.FILLCOLOR, palette); /* fill describes what colour to draw the graph based on a portion of the data */ // node text ColorAction text = new ColorAction("socialnet.nodes", VisualItem.TEXTCOLOR, ColorLib.gray(0)); /* text describes what colour to draw the text */ // edge ColorAction edges = new ColorAction("socialnet.edges", VisualItem.STROKECOLOR, ColorLib.gray(200)); ColorAction arrow = new ColorAction("socialnet.edges", VisualItem.FILLCOLOR, ColorLib.gray(200)); /* edge describes what colour to draw the edges */ // combine the colour assignments into an action list ActionList colour = new ActionList(); colour.add(fill); colour.add(text); colour.add(edges); colour.add(arrow); vis.putAction("colour", colour); /* add the colour actions to the visualization */ // create a separate action list for the layout ActionList layout = new ActionList(Activity.INFINITY); layout.add(new ForceDirectedLayout("socialnet")); /* use a force-directed graph layout with default parameters */ layout.add(new RepaintAction()); /* repaint after each movement of the graph nodes */ vis.putAction("layout", layout); /* add the laout actions to the visualization */ // 5. add interactive controls for visualization Display display = new Display(vis); display.setSize(700, 700); display.pan(350, 350); // pan to the middle display.addControlListener(new DragControl()); /* allow items to be dragged around */ display.addControlListener(new PanControl()); /* allow the display to be panned (moved left/right, up/down) (left-drag)*/ display.addControlListener(new ZoomControl()); /* allow the display to be zoomed (right-drag) */ // 6. launch the visualizer in a JFrame JFrame frame = new JFrame("prefuse tutorial: socialnet"); /* frame is the main window */ frame.setDefaultCloseOperation(JFrame.EXIT_ON_CLOSE); frame.add(display); /* add the display (which holds the visualization) to the window */ frame.pack(); frame.setVisible(true); /* start the visualization working */ vis.run("colour"); vis.run("layout"); } }

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  • Uploading multiple files using Spring MVC 3.0.2 after HiddenHttpMethodFilter has been enabled

    - by Tiny
    I'm using Spring version 3.0.2. I need to upload multiple files using the multiple="multiple" attribute of a file browser such as, <input type="file" id="myFile" name="myFile" multiple="multiple"/> (and not using multiple file browsers something like the one stated by this answer, it indeed works I tried). Although no versions of Internet Explorer supports this approach unless an appropriate jQuery plugin/widget is used, I don't care about it right now (since most other browsers support this). This works fine with commons fileupload but in addition to using RequestMethod.POST and RequestMethod.GET methods, I also want to use other request methods supported and suggested by Spring like RequestMethod.PUT and RequestMethod.DELETE in their own appropriate places. For this to be so, I have configured Spring with HiddenHttpMethodFilter which goes fine as this question indicates. but it can upload only one file at a time even though multiple files in the file browser are chosen. In the Spring controller class, a method is mapped as follows. @RequestMapping(method={RequestMethod.POST}, value={"admin_side/Temp"}) public String onSubmit(@RequestParam("myFile") List<MultipartFile> files, @ModelAttribute("tempBean") TempBean tempBean, BindingResult error, Map model, HttpServletRequest request, HttpServletResponse response) throws IOException, FileUploadException { for(MultipartFile file:files) { System.out.println(file.getOriginalFilename()); } } Even with the request parameter @RequestParam("myFile") List<MultipartFile> files which is a List of type MultipartFile (it can always have only one file at a time). I could find a strategy which is likely to work with multiple files on this blog. I have gone through it carefully. The solution below the section SOLUTION 2 – USE THE RAW REQUEST says, If however the client insists on using the same form input name such as ‘files[]‘ or ‘files’ and then populating that name with multiple files then a small hack is necessary as follows. As noted above Spring 2.5 throws an exception if it detects the same form input name of type file more than once. CommonsFileUploadSupport – the class which throws that exception is not final and the method which throws that exception is protected so using the wonders of inheritance and subclassing one can simply fix/modify the logic a little bit as follows. The change I’ve made is literally one word representing one method invocation which enables us to have multiple files incoming under the same form input name. It attempts to override the method protected MultipartParsingResult parseFileItems(List fileItems, String encoding) {} of the abstract class CommonsFileUploadSupport by extending the class CommonsMultipartResolver such as, package multipartResolver; import java.io.UnsupportedEncodingException; import java.util.HashMap; import java.util.Iterator; import java.util.List; import java.util.Map; import javax.servlet.ServletContext; import org.apache.commons.fileupload.FileItem; import org.springframework.util.StringUtils; import org.springframework.web.multipart.MultipartException; import org.springframework.web.multipart.MultipartFile; import org.springframework.web.multipart.commons.CommonsMultipartFile; import org.springframework.web.multipart.commons.CommonsMultipartResolver; final public class MultiCommonsMultipartResolver extends CommonsMultipartResolver { public MultiCommonsMultipartResolver() { } public MultiCommonsMultipartResolver(ServletContext servletContext) { super(servletContext); } @Override @SuppressWarnings("unchecked") protected MultipartParsingResult parseFileItems(List fileItems, String encoding) { Map<String, MultipartFile> multipartFiles = new HashMap<String, MultipartFile>(); Map multipartParameters = new HashMap(); // Extract multipart files and multipart parameters. for (Iterator it = fileItems.iterator(); it.hasNext();) { FileItem fileItem = (FileItem) it.next(); if (fileItem.isFormField()) { String value = null; if (encoding != null) { try { value = fileItem.getString(encoding); } catch (UnsupportedEncodingException ex) { if (logger.isWarnEnabled()) { logger.warn("Could not decode multipart item '" + fileItem.getFieldName() + "' with encoding '" + encoding + "': using platform default"); } value = fileItem.getString(); } } else { value = fileItem.getString(); } String[] curParam = (String[]) multipartParameters.get(fileItem.getFieldName()); if (curParam == null) { // simple form field multipartParameters.put(fileItem.getFieldName(), new String[] { value }); } else { // array of simple form fields String[] newParam = StringUtils.addStringToArray(curParam, value); multipartParameters.put(fileItem.getFieldName(), newParam); } } else { // multipart file field CommonsMultipartFile file = new CommonsMultipartFile(fileItem); if (multipartFiles.put(fileItem.getName(), file) != null) { throw new MultipartException("Multiple files for field name [" + file.getName() + "] found - not supported by MultipartResolver"); } if (logger.isDebugEnabled()) { logger.debug("Found multipart file [" + file.getName() + "] of size " + file.getSize() + " bytes with original filename [" + file.getOriginalFilename() + "], stored " + file.getStorageDescription()); } } } return new MultipartParsingResult(multipartFiles, multipartParameters); } } What happens is that the last line in the method parseFileItems() (the return statement) i.e. return new MultipartParsingResult(multipartFiles, multipartParameters); causes a compile-time error because the first parameter multipartFiles is a type of Map implemented by HashMap but in reality, it requires a parameter of type MultiValueMap<String, MultipartFile> It is a constructor of a static class inside the abstract class CommonsFileUploadSupport, public abstract class CommonsFileUploadSupport { protected static class MultipartParsingResult { public MultipartParsingResult(MultiValueMap<String, MultipartFile> mpFiles, Map<String, String[]> mpParams) { } } } The reason might be - this solution is about the Spring version 2.5 and I'm using the Spring version 3.0.2 which might be inappropriate for this version. I however tried to replace the Map with MultiValueMap in various ways such as the one shown in the following segment of code, MultiValueMap<String, MultipartFile>mul=new LinkedMultiValueMap<String, MultipartFile>(); for(Entry<String, MultipartFile>entry:multipartFiles.entrySet()) { mul.add(entry.getKey(), entry.getValue()); } return new MultipartParsingResult(mul, multipartParameters); but no success. I'm not sure how to replace Map with MultiValueMap and even doing so could work either. After doing this, the browser shows the Http response, HTTP Status 400 - type Status report message description The request sent by the client was syntactically incorrect (). Apache Tomcat/6.0.26 I have tried to shorten the question as possible as I could and I haven't included unnecessary code. How could be made it possible to upload multiple files after Spring has been configured with HiddenHttpMethodFilter? That blog indicates that It is a long standing, high priority bug. If there is no solution regarding the version 3.0.2 (3 or higher) then I have to disable Spring support forever and continue to use commons-fileupolad as suggested by the third solution on that blog omitting the PUT, DELETE and other request methods forever. Just curiously waiting for a solution and/or suggestion. Very little changes to the code in the parseFileItems() method inside the class MultiCommonsMultipartResolver might make it to upload multiple files but I couldn't succeed in my attempts (again with the Spring version 3.0.2 (3 or higher)).

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  • Migrate existing Maven Project into an OSGI Bundle

    - by user1706291
    i am new to the whole OSGi stuff and my task is to create an OSGi Bundle out from an exisitng maven project. To get started i decided to pick the smallest part and starting with it: Here is the pom.xml project xmlns="http://maven.apache.org/POM/4.0.0" xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance" xsi:schemaLocation="http://maven.apache.org/POM/4.0.0 http://maven.apache.org/maven-v4_0_0.xsd"> <modelVersion>4.0.0</modelVersion> <parent> <artifactId>cross</artifactId> <groupId>net.sf.maltcms</groupId> <version>1.2.12-SNAPSHOT</version> </parent> <artifactId>cross-main</artifactId> <packaging>jar</packaging> <name>cross-main</name> <dependencies> <dependency> <groupId>${project.groupId}</groupId> <artifactId>cross-annotations</artifactId> <version>${project.version}</version> </dependency> <dependency> <groupId>${project.groupId}</groupId> <artifactId>cross-event</artifactId> <version>${project.version}</version> </dependency> <dependency> <groupId>${project.groupId}</groupId> <artifactId>cross-tools</artifactId> <version>${project.version}</version> </dependency> <dependency> <groupId>${project.groupId}</groupId> <artifactId>cross-exception</artifactId> <version>${project.version}</version> </dependency> <dependency> <groupId>commons-codec</groupId> <artifactId>commons-codec</artifactId> <version>1.4</version> </dependency> <dependency> <groupId>${project.groupId}</groupId> <artifactId>cross-main-api</artifactId> <version>${project.version}</version> <exclusions> <exclusion> <artifactId>commons-logging</artifactId> <groupId>commons-logging</groupId> </exclusion> </exclusions> </dependency> <dependency> <groupId>org.springframework</groupId> <artifactId>spring-aop</artifactId> <version>3.0.6.RELEASE</version> </dependency> <dependency> <groupId>org.springframework</groupId> <artifactId>spring-asm</artifactId> <version>3.0.6.RELEASE</version> </dependency> <dependency> <groupId>org.springframework</groupId> <artifactId>spring-beans</artifactId> <version>3.0.6.RELEASE</version> </dependency> <dependency> <groupId>org.springframework</groupId> <artifactId>spring-context</artifactId> <version>3.0.6.RELEASE</version> </dependency> <dependency> <groupId>org.springframework</groupId> <artifactId>spring-core</artifactId> <version>3.0.6.RELEASE</version> <exclusions> <exclusion> <artifactId>commons-logging</artifactId> <groupId>commons-logging</groupId> </exclusion> </exclusions> </dependency> <dependency> <groupId>org.springframework</groupId> <artifactId>spring-expression</artifactId> <version>3.0.6.RELEASE</version> </dependency> <dependency> <groupId>commons-io</groupId> <artifactId>commons-io</artifactId> <version>2.1</version> </dependency> <dependency> <groupId>net.sf.ehcache</groupId> <artifactId>ehcache-core</artifactId> <version>2.4.6</version> </dependency> <dependency> <groupId>${project.groupId}</groupId> <artifactId>cross-math</artifactId> <version>${project.version}</version> </dependency> <dependency> <groupId>com.db4o</groupId> <artifactId>db4o-all</artifactId> <version>8.0.249</version> </dependency> <dependency> <groupId>net.sf.mpaxs</groupId> <artifactId>mpaxs-spi</artifactId> <version>1.6.10</version> </dependency> <dependency> <groupId>net.sf.mpaxs</groupId> <artifactId>mpaxs-server</artifactId> <version>1.6.10</version> </dependency> </dependencies> I did some research and found the Apache Bundle Plugin for maven and changed the pom to this <packaging>bundle</packaging> and added <build> <plugins> <plugin> <groupId>org.apache.felix</groupId> <artifactId>maven-bundle-plugin</artifactId> <extensions>true</extensions> <configuration> <instructions> <Bundle-SymbolicName>${pom.artifactId}</Bundle-SymbolicName> </instructions> </configuration> </plugin> </plugins> </build> mvn clean install went fine and i got a jar file containing the manifest, but of course the bundle could not be resolved BundleException: The bundle "cross-main_1.2.12.SNAPSHOT [30]" could not be resolved. Reason: Missing Constraint: Import-Package: com.db4o; version="[8.0.0,9.0.0) To make a long story short: What are the possibiliteis to migrate a maven application into an OSGi Bundle? Espacially how to manage the dependencys

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