object relational model - Page 682

A very strange problem related to Flash and Java

- by Nitesh Panchal

Hello, I have created one simple program for showing webcam of the user. It works absolutely fine when i am running without integrating it in my java web application. But as soon as i copy paste the same files in Netbeans 6.8 and try to run it. My swf file is visible but the buttons in it are totally unclickable. I get the message of allow or deny showing webcam but the buttons are not clickable. It makes my application totally useless. I thought it's a minor issue but now it's getting on my nerves. I am trying it since 3 hours but didn't find any solution. I don't think anybody faced this issue till now that's why can't seem to find any thread in any forum on it in google. I am using Netbeans 6.8, Ubuntu, Glassfish V3 and JSF. Thanks in advance :). UPDATE:- It works fine on Windows XP. Then what can be the problem with Ubuntu? Any kind of permission rights that i need to give? 2nd UPDATE:- I think this is bug with Flash. I found that this code doesn't work :- <object classid="clsid:d27cdb6e-ae6d-11cf-96b8-444553540000" codebase="http://download.macromedia.com/pub/shockwave/cabs/flash/swflash.cab#version=9,0,0,0" id="VideoConferenceAdmin" align="middle"> <param name="allowScriptAccess" value="sameDomain" /> <param name="wmode" value="opaque"/> <param name="allowFullScreen" value="false" /> <param NAME="FlashVars" VALUE="rootIp=localhost&userName=admin&roomName=test" /> <param name="movie" value="Conference/VideoConference.swf" /><param name="quality" value="high" /> <embed src="Conference/VideoConference.swf" wmode="window" FlashVars="rootIp=localhost&userName=test&roomName=test" quality="high" width="600" height="500" name="VideoConference" align="middle" allowScriptAccess="sameDomain" allowFullScreen="false" type="application/x-shockwave-flash" pluginspage="http://www.macromedia.com/go/getflashplayer" /> </object> And this one works :- <object classid="clsid:d27cdb6e-ae6d-11cf-96b8-444553540000" codebase="http://download.macromedia.com/pub/shockwave/cabs/flash/swflash.cab#version=9,0,0,0" id="VideoConferenceAdmin" align="middle"> <param name="allowScriptAccess" value="sameDomain" /> <param name="wmode" value="opaque"/> <param name="allowFullScreen" value="false" /> <param NAME="FlashVars" VALUE="rootIp=localhost&userName=admin&roomName=test" /> <param name="movie" value="Conference/VideoConference.swf" /><param name="quality" value="high" /> <embed src="Conference/VideoConference.swf" wmode="window" FlashVars="rootIp=localhost&userName=test&roomName=test" quality="high" name="VideoConference" align="middle" allowScriptAccess="sameDomain" allowFullScreen="false" type="application/x-shockwave-flash" pluginspage="http://www.macromedia.com/go/getflashplayer" /> </object> As you can see, just by removing the height and width attribute the panels of Flash settings work fine. I know you will find me funny but i am not. You can check out on your own if you don't trust me. Now, my question would be, can anybody tell me how do i set height and width of swf? I want it to be 600px width and 500px height. Even the style attribute doesn't work. Can i set height and width from within Flash? because without explicitly setting height and width, it looks very small. I think this should be very easy for all now. Thanks in advance :)

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onCommand on button not firing inside gridView??

- by sah302

This is really driving me crazy. I've got a button inside a gridview to remove that item from the gridview (its datasource is a list). I've got the list being saved to session anytime a change is being made to it, and on page_load check if that session variable is empty, if not, then set that list to bind to the gridview. Code Behind: Public accomplishmentTypeDao As New AccomplishmentTypeDao() Public accomplishmentDao As New AccomplishmentDao() Public userDao As New UserDao() Public facultyDictionary As New Dictionary(Of Guid, String) Public facultyList As New List(Of User) Public associatedFaculty As New List(Of User) Public facultyId As New Guid Protected Sub Page_Load(ByVal sender As Object, ByVal e As System.EventArgs) Handles Me.Load 'If Not Session("associatedFaculty") Is Nothing Then' ' Dim associatedFacultyArray As User() = DirectCast(Session("associatedFaculty"), User())' ' associatedFaculty = associatedFacultyArray.ToList()' 'End If' Page.Title = "Add a New Faculty Accomplishment" ddlAccomplishmentType.DataSource = accomplishmentTypeDao.getEntireTable() ddlAccomplishmentType.DataTextField = "Name" ddlAccomplishmentType.DataValueField = "Id" ddlAccomplishmentType.DataBind() facultyList = userDao.getListOfUsersByUserGroupName("Faculty") For Each faculty As User In facultyList facultyDictionary.Add(faculty.Id, faculty.LastName & ", " & faculty.FirstName) Next If Not Page.IsPostBack Then ddlFacultyList.DataSource = facultyDictionary ddlFacultyList.DataTextField = "Value" ddlFacultyList.DataValueField = "Key" ddlFacultyList.DataBind() End If gvAssociatedUsers.DataSource = associatedFaculty gvAssociatedUsers.DataBind() End Sub Protected Sub deleteUser(ByVal sender As Object, ByVal e As System.Web.UI.WebControls.CommandEventArgs) facultyId = New Guid(e.CommandArgument.ToString()) associatedFaculty.Remove(associatedFaculty.Find(Function(user) user.Id = facultyId)) Session("associatedFaculty") = associatedFaculty.ToArray() gvAssociatedUsers.DataBind() upAssociatedFaculty.Update() End Sub Protected Sub btnAddUser_Click(ByVal sender As Object, ByVal e As EventArgs) Handles btnAddUser.Click facultyId = New Guid(ddlFacultyList.SelectedValue) associatedFaculty.Add(facultyList.Find(Function(user) user.Id = facultyId)) Session.Add("associatedFaculty", associatedFaculty.ToArray()) gvAssociatedUsers.DataBind() upAssociatedFaculty.Update() End Sub Protected Sub Delete(ByVal sender As Object, ByVal e As System.Web.UI.WebControls.CommandEventArgs) End Sub End Class Markup: <asp:UpdatePanel ID="upAssociatedFaculty" runat="server" UpdateMode="Conditional"> <ContentTemplate> <p><b>Created By:</b> <asp:Label ID="lblCreatedBy" runat="server"></asp:Label></p> <p><b>Accomplishment Type: </b><asp:DropDownList ID="ddlAccomplishmentType" runat="server"></asp:DropDownList></p> <p><b>Accomplishment Applies To: </b><asp:DropDownList ID="ddlFacultyList" runat="server"></asp:DropDownList>  <asp:Button ID="btnAddUser" runat="server" Text="Add Faculty" OnClientClick="incrementCounter();" /></p> <p> <asp:GridView ID="gvAssociatedUsers" runat="server" AutoGenerateColumns="false" GridLines="None" ShowHeader="false"> <Columns> <asp:BoundField DataField="Id" HeaderText="Id" Visible="False" /> <asp:TemplateField ShowHeader="False"> <ItemTemplate> <span style="margin-left: 15px;"> <p><%#Eval("LastName")%>, <%#Eval("FirstName")%> <asp:Button ID="btnUnassignUser" runat="server" CausesValidation="false" CommandArgument='<%# Eval("Id") %>' CommandName="Delete" OnCommand="deleteUser" Text='Remove' /></p> </span> </ItemTemplate> </asp:TemplateField> </Columns> <EmptyDataTemplate> <em>There are currently no faculty associated with this accomplishment.</em> </EmptyDataTemplate> </asp:GridView> </p> </ContentTemplate> </asp:UpdatePanel> Now here is the crazy part I am simply boggled by, if I uncomment the If Not Session... block of page_load, then deleteUser will never fire when btnUnassignUser is clicked. If I keep it commented out...it fires no problem, but then of course my list can never have more than one item since I am not loading the saved list from session into the gridview but just a fresh one. But the button click is being registered, because page_load is being stepped through again when I am viewing in debug mode, just deleteUser never fires. Why is this happening?? And how can I fix it??

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Drawing outlines around organic shapes

- by ThunderChunky_SF

One thing that seems particularly easy to do in the Flash IDE but difficult to do with code is to outline an organic shape. In the IDE you can just use the inkbucket tool to draw a stroke around something. Using nothing but code it seems much trickier. One method I've seen is to add a glow filter to the shape in question and just mess with the strength. But what if i want to only show the outline? What I'd like to do is to collect all of the points that make up the edge of the shape and then just connect the dots. I've actually gotten so far as to collect all of the points with a quick and dirty edge detection script that I wrote. So now I have a Vector of all the points that makeup my shape. How do I connect them in the proper sequence so it actually looks like the original object? For anyone who is interested here is my edge detection script: // Create a new sprite which we'll use for our outline var sp:Sprite = new Sprite(); var radius:int = 50; sp.graphics.beginFill(0x00FF00, 1); sp.graphics.drawCircle(0, 0, radius); sp.graphics.endFill(); sp.x = stage.stageWidth / 2; sp.y = stage.stageHeight / 2; // Create a bitmap data object to draw our vector data var bmd:BitmapData = new BitmapData(sp.width, sp.height, true, 0); // Use a transform matrix to translate the drawn clip so that none of its // pixels reside in negative space. The draw method will only draw starting // at 0,0 var mat:Matrix = new Matrix(1, 0, 0, 1, radius, radius); bmd.draw(sp, mat); // Pass the bitmap data to an actual bitmap var bmp:Bitmap = new Bitmap(bmd); // Add the bitmap to the stage addChild(bmp); // Grab all of the pixel data from the bitmap data object var pixels:Vector.<uint> = bmd.getVector(bmd.rect); // Setup a vector to hold our stroke points var points:Vector.<Point> = new Vector.<Point>; // Loop through all of the pixels of the bitmap data object and // create a point instance for each pixel location that isn't // transparent. var l:int = pixels.length; for(var i:int = 0; i < l; ++i) { // Check to see if the pixel is transparent if(pixels[i] != 0) { var pt:Point; // Check to see if the pixel is on the first or last // row. We'll grab everything from these rows to close the outline if(i <= bmp.width || i >= (bmp.width * bmp.height) - bmp.width) { pt = new Point(); pt.x = int(i % bmp.width); pt.y = int(i / bmp.width); points.push(pt); continue; } // Check to see if the current pixel is on either extreme edge if(int(i % bmp.width) == 0 || int(i % bmp.width) == bmp.width - 1) { pt = new Point(); pt.x = int(i % bmp.width); pt.y = int(i / bmp.width); points.push(pt); continue; } // Check to see if the previous or next pixel are transparent, // if so save the current one. if(i > 0 && i < bmp.width * bmp.height) { if(pixels[i - 1] == 0 || pixels[i + 1] == 0) { pt = new Point(); pt.x = int(i % bmp.width); pt.y = int(i / bmp.width); points.push(pt); } } } }

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Creating a file upload template in Doctrine ORM

- by balupton

Hey all. I'm using Doctrine 1.2 as my ORM for a Zend Framework Project. I have defined the following Model for a File. File: columns: id: primary: true type: integer(4) unsigned: true code: type: string(255) unique: true notblank: true path: type: string(255) notblank: true size: type: integer(4) type: type: enum values: [file,document,image,video,audio,web,application,archive] default: unknown notnull: true mimetype: type: string(20) notnull: true width: type: integer(2) unsigned: true height: type: integer(2) unsigned: true Now here is the File Model php class (just skim through for now): <?php /** * File * * This class has been auto-generated by the Doctrine ORM Framework * * @package ##PACKAGE## * @subpackage ##SUBPACKAGE## * @author ##NAME## <##EMAIL##> * @version SVN: $Id: Builder.php 6365 2009-09-15 18:22:38Z jwage $ */ class File extends BaseFile { public function setUp ( ) { $this->hasMutator('file', 'setFile'); parent::setUp(); } public function setFile ( $file ) { global $Application; // Configuration $config = array(); $config['bal'] = $Application->getOption('bal'); // Check the file if ( !empty($file['error']) ) { $error = $file['error']; switch ( $file['error'] ) { case UPLOAD_ERR_INI_SIZE : $error = 'ini_size'; break; case UPLOAD_ERR_FORM_SIZE : $error = 'form_size'; break; case UPLOAD_ERR_PARTIAL : $error = 'partial'; break; case UPLOAD_ERR_NO_FILE : $error = 'no_file'; break; case UPLOAD_ERR_NO_TMP_DIR : $error = 'no_tmp_dir'; break; case UPLOAD_ERR_CANT_WRITE : $error = 'cant_write'; break; default : $error = 'unknown'; break; } throw new Doctrine_Exception('error-application-file-' . $error); return false; } if ( empty($file['tmp_name']) || !is_uploaded_file($file['tmp_name']) ) { throw new Doctrine_Exception('error-application-file-invalid'); return false; } // Prepare config $file_upload_path = realpath($config['bal']['files']['upload_path']) . DIRECTORY_SEPARATOR; // Prepare file $filename = $file['name']; $file_old_path = $file['tmp_name']; $file_new_path = $file_upload_path . $filename; $exist_attempt = 0; while ( file_exists($file_new_path) ) { // File already exists // Pump exist attempts ++$exist_attempt; // Add the attempt to the end of the file $file_new_path = $file_upload_path . get_filename($filename,false) . $exist_attempt . get_extension($filename); } // Move file $success = move_uploaded_file($file_old_path, $file_new_path); if ( !$success ) { throw new Doctrine_Exception('Unable to upload the file.'); return false; } // Secure $file_path = realpath($file_new_path); $file_size = filesize($file_path); $file_mimetype = get_mime_type($file_path); $file_type = get_filetype($file_path); // Apply $this->path = $file_path; $this->size = $file_size; $this->mimetype = $file_mimetype; $this->type = $file_type; // Apply: Image if ( $file_type === 'image' ) { $image_dimensions = image_dimensions($file_path); if ( !empty($image_dimensions) ) { // It is not a image we can modify $this->width = 0; $this->height = 0; } else { $this->width = $image_dimensions['width']; $this->height = $image_dimensions['height']; } } // Done return true; } /** * Download the File * @return */ public function download ( ) { global $Application; // File path $file_upload_path = realpath($config['bal']['files']['upload_path']) . DIRECTORY_SEPARATOR; $file_path = $file_upload_path . $this->file_path; // Output result and download become_file_download($file_path, null, null); die(); } public function postDelete ( $Event ) { global $Application; // Prepare $Invoker = $Event->getInvoker(); // Configuration $config = array(); $config['bal'] = $Application->getOption('bal'); // File path $file_upload_path = realpath($config['bal']['files']['upload_path']) . DIRECTORY_SEPARATOR; $file_path = $file_upload_path . $this->file_path; // Delete the file unlink($file_path); // Done return true; } } What I am hoping to accomplish is so that the above custom functionality within my model file can be turned into a validator, template, or something along the lines. So hopefully I can do something like: File: actAs: BalFile: columns: id: primary: true type: integer(4) unsigned: true code: type: string(255) unique: true notblank: true path: type: string(255) notblank: true size: type: integer(4) type: type: enum values: [file,document,image,video,audio,web,application,archive] default: unknown notnull: true mimetype: type: string(20) notnull: true width: type: integer(2) unsigned: true height: type: integer(2) unsigned: true I'm hoping for a validator so that say if I do $File->setFile($_FILE['uploaded_file']); It will provide a validation error, except in all the doctrine documentation it has little on custom validators, especially in the contect of "virtual" fields. So in summary, my question is: How earth can I go about making a template/extension to porting this functionality? I have tried before with templates but always gave up after a day :/ If you could take the time to port the above I would greatly appreciate it.

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how use graphvis in C# application?

- by ghasedak -

i have a dot format file and i download graphvis for windows now how can i use graphvis to show a graph in my c# application? using System; using System.Collections.Generic; using System.ComponentModel; using System.Data; using System.Drawing; using System.Linq; using System.Text; using System.Windows.Forms; using VDS.RDF; using VDS.RDF.Parsing; using VDS.RDF.Query; using System.IO; using System.Windows; using System.Runtime.InteropServices; using VDS.RDF.Writing; using System.Diagnostics; namespace WindowsFormsApplication2 { public partial class first : Form { Graph g = new Graph(); string s1 = null; /**************************************DATA********************************************/ public first() { InitializeComponent(); } private void button1_Click(object sender, EventArgs e) { Stream myStream = null; var parser = new Notation3Parser(); var graph = new Graph(); OpenFileDialog openFileDialog1 = new OpenFileDialog(); openFileDialog1.Filter = "RDF files (*.n3)|*.n3"; openFileDialog1.FilterIndex = 1; openFileDialog1.RestoreDirectory = true; openFileDialog1.Multiselect = false; if (openFileDialog1.ShowDialog() == DialogResult.OK) { try { if ((myStream = openFileDialog1.OpenFile()) != null) { using (myStream) { string s = openFileDialog1.FileName.ToString(); string w= Directory.GetCurrentDirectory().ToString(); string Fname = openFileDialog1.SafeFileName.ToString(); File.Copy(s,Path.Combine(w,Fname),true); // Insert code to read the stream here. Win32.AllocConsole(); s1 = Path.Combine(w, Fname); insertNodeButton.Visible = true; delBut.Visible = true; simi.Visible = true; showNodes showNodes1 = new showNodes(s1); g = showNodes1.returngraph(); Console.Read(); Win32.FreeConsole(); // g.SaveToFile("firstfile.n3"); this.Show(); } } } catch (Exception ex) { MessageBox.Show("Error: Could not read file from disk. Original error: " + ex.Message); } } GraphVizWriter hi = new GraphVizWriter(); hi.Save(g, "c:\\ahmad.dot"); } private void button2_Click(object sender, EventArgs e) { string strCmdLine = Application.StartupPath + "\\Tools\\rdfEditor.exe"; //string strCmdLine = "DIR"; MessageBox.Show(strCmdLine); System.Diagnostics.Process process1; process1 = new System.Diagnostics.Process(); //Do not receive an event when the process exits. process1.EnableRaisingEvents = false; //The "/C" Tells Windows to Run The Command then Terminate System.Diagnostics.Process.Start(strCmdLine); process1.Close(); } private void Form1_Load(object sender, EventArgs e) { } private void insertNodeButton_Click(object sender, EventArgs e) { //Graph parentvalue = this.g; //String parentvalueadress = this.s1; addTriple a1 = new addTriple(); a1.G = g; a1.BringToFront(); a1.ShowDialog(); g = a1.G; g.SaveToFile("c:\\Hi.n3"); } this is my code i want to visul saly dot file format to show a graph with graphvis

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The impossible inline Javascript delay/sleep

- by trex005

There is a JavaScript function, of which I have zero control of the code, which calls a function that I wrote. My function uses DOM to generate an iFrame, defines it's src and then appends it to another DOM element. However, before my function returns, and thus allows continued execution of the containing function, it is imperative that the iFrame be fully loaded. Here are the things that I have tried and why they do not work : 1. The SetTimeout option : 99.999% of the time, this is THE answer. As a matter of fact, in the past decade that I have been mentoring in JavaScript, I have always insisted that code could always be refactored to use this option, and never believed a scenario existed where that was not the case. Well, I finally found one! The problem is that because my function is being called inline, if the very next line is executed before my iFrame finishes loading, it totally neuters my script, and since the moment my script completes, the external script continues. A callback of sorts will not work 2. The "Do nothing" loop :This option you use while(//iFrame is not loaded){//do nothing}. In theory this would not return until the frame is loaded. The problem is that since this hogs all the resources, the iFrame never loads. This trick, although horribly unprofessional, dirty etc. will work when you just need an inline delay, but since I require an external thread to complete, it will not.In FF, after a few seconds, it pauses the script and an alert pops up stating that there is an unresponsive script. While that alert is up, the iFrame is able to load, and then my function is able to return, but having the browser frozen for 10 seconds, and then requiring the user to correctly dismiss an error is a no go. 3. The model dialogue : I was inspired by the fact that the FF popup allowed the iFrame to load while halting the execution of the function, and thinking about it, I realized that it is because the modal dialogue, is a way of halting execution yet allowing other threads to continue! Brilliant, so I decided to try other modal options. Things like alert() work beautifully! When it pops up, even if only up for 1/10th of a second, the iFrame is able to complete, and all works great. And just in case the 1/10 of a second is not sufficient, I can put the model dialogue in the while loop from solution 2, and it would ensure that the iFrame is loaded in time. Sweet right? Except for the fact that I now have to pop up a very unprofessional dialogue for the user to dismiss in order to run my script. I fought with myself about this cost/benefit of this action, but then I encountered a scenario where my code was called 10 times on a single page! Having to dismiss 10 alerts before acessing a page?! That reminds me of the late 90s script kiddie pages, and is NOT an option. 4. A gazillion other delay script out there:There are about 10 jQuery delay or sleep functions, some of them actually quite cleverly developed, but none worked. A few prototype options, and again, none I found could do it! A dozen or so other libraries and frameworks claimed they had what I needed, but alas they all conspired to give me false hope. I am convinced that since a built in model dialogue can halt execution, while allowing other threads to continue, there must be some code accessible way to do the same thing with out user input. The Code is literally thousands upon thousands of lines and is proprietary, so I wrote this little example of the problem for you to work with. It is important to note the ONLY code you are able to change is in the onlyThingYouCanChange function Test File : <html> <head> </head> </html> <body> <div id='iFrameHolder'></div> <script type='text/javascript'> function unChangeableFunction() { new_iFrame = onlyThingYouCanChange(document.getElementById('iFrameHolder')); new_iFrame_doc = (new_iFrame.contentWindow || new_iFrame.contentDocument); if(new_iFrame_doc.document)new_iFrame_doc=new_iFrame_doc.document; new_iFrame_body = new_iFrame_doc.body; if(new_iFrame_body.innerHTML != 'Loaded?') { //The world explodes!!! alert('you just blew up the world! Way to go!'); } else { alert('wow, you did it! Way to go!'); } } var iFrameLoaded = false; function onlyThingYouCanChange(objectToAppendIFrameTo) { iFrameLoaded = false; iframe=document.createElement('iframe'); iframe.onload = new Function('iFrameLoaded = true'); iframe.src = 'blank_frame.html'; //Must use an HTML doc on the server because there is a very specific DOM structure that must be maintained. objectToAppendIFrameTo.appendChild(iframe); var it = 0; while(!iFrameLoaded) //I put the limit on here so you don't { //If I was able to put some sort of delay here that paused the exicution of the script, but did not halt all other browser threads, and did not require user interaction we'd be golden! //alert('test'); //This would work if it did not require user interaction! } return iframe; } unChangeableFunction(); </script> </body> blank_frame.html : <html> <head> </head> <body style='margin:0px'>Loaded?</body> </html>

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What's the best-practice way to update an Adapter's underlying data?

- by skyler

I'm running into an IllegalStateException updating an underlying List to an Adapter (might be an ArrayAdapter or an extension of BaseAdapter, I don't remember). I do not have or remember the text of the exception at the moment, but it says something to the effect of the List's content changing without the Adapter having been notified of the change. This List /may/ be updated from another thread other than the UI thread (main). After I update this list (adding an item), I call notifyDataSetChanged. The issue seems to be that the Adapter, or ListView attached to the Adapter attempts to update itself before this method is invoked. When this happens, the IllegalStateException is thrown. If I set the ListView's visibility to GONE before the update, then VISIBLE again, no error occurs. But this isn't always practical. I read somewhere that you cannot modify the underlying this from another thread--this would seem to limit an MVC pattern, as with this particular List, I want to add items from different threads. I assumed that as long as I called notifyDataSetChanged() I'd be safe--that the Adapter didn't revisit the underlying List until this method was invoked but this doesn't seem to be the case. I suppose what I'm asking is, can it be safe to update the underlying List from threads other than the UI? Additionally, if I want to modify the data within an Adapter, do I modify the underlying List or the Adapter itself (via its add(), etc. methods). Modifying the data through the Adapter seems wrong. I came across a thread on another site from someone who seems to be having a similar problem to mine: http://osdir.com/ml/Android-Developers/2010-04/msg01199.html (this is from where I grabbed the Visibility.GONE and .VISIBLE idea). To give you a better idea of my particular problem, I'll describe a bit of how my List, Adapter, etc. are set up. I've an object named Queue that contains a LinkedList. Queue extends Observable, and when things are added to its internal list through its methods, I call setChanged() and notifyListeners(). This Queue object can have items added or removed from any number of threads. I have a single "queue view" Activity that contains an Adapter. This Activity, in its onCreate() method, registers an Observer listener to my Queue object. In the Observer's update() method I call notifyDataSetChanged() on the Adapter. I added a lot of log output and determined that when this IllegalStateExcption occurs that my Observer callback was never invoked. So it's as if the Adapter noticed the List's change before the Observer had a chance to notify its Observers, and call my method to notify the Adapter that the contents had changed. So I suppose what I'm asking is, is this a good way to rig-up an Adapter? Is this a problem because I'm updating the Adapter's contents from a thread other than the UI thread? If this is the case, I may have a solution in mind (give the Queue object a Handler to the UI thread when it's created, and make all List modifications using that Handler, but this seems improper). I realize that this is a very open-ended post, but I'm a bit lost on this and would appreciate any comments on what I've written.

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JTable how to change BackGround Color

- by mKorbel

I inspired by MeBigFatGuy interesting question, in this conection I have very specific question about Graphisc2D, how to change BackGround Color by depends if is JTables Row visible in the JViewPort, 1) if 1st. & last JTables Row will be visible in the JViewPort, then BackGround would be colored to the Color.red 2) if 1st. & last JTables Row will not be visible in the JViewPort, then BackGround would be colored to the Color.whatever from SSCCE import java.awt.*; import java.awt.event.ActionEvent; import java.awt.image.BufferedImage; import javax.swing.*; import javax.swing.RepaintManager; import javax.swing.event.ChangeEvent; import javax.swing.event.ChangeListener; import javax.swing.table.TableModel; /* http://stackoverflow.com/questions/1249278/ how-to-disable-the-default-painting-behaviour-of-wheel-scroll-event-on-jscrollpan * and * http://stackoverflow.com/questions/8195959/ swing-jtable-event-when-row-is-visible-or-when-scrolled-to-the-bottom */ public class ViewPortFlickering { private JFrame frame = new JFrame("Table"); private JViewport viewport = new JViewport(); private Rectangle RECT = new Rectangle(); private Rectangle RECT1 = new Rectangle(); private JTable table = new JTable(50, 3); private javax.swing.Timer timer; private int count = 0; public ViewPortFlickering() { GradientViewPort tableViewPort = new GradientViewPort(table); viewport = tableViewPort.getViewport(); viewport.addChangeListener(new ChangeListener() { @Override public void stateChanged(ChangeEvent e) { RECT = table.getCellRect(0, 0, true); RECT1 = table.getCellRect(table.getRowCount() - 1, 0, true); Rectangle viewRect = viewport.getViewRect(); if (viewRect.intersects(RECT)) { System.out.println("Visible RECT -> " + RECT); } else if (viewRect.intersects(RECT1)) { System.out.println("Visible RECT1 -> " + RECT1); } else { // } } }); frame.add(tableViewPort); frame.setPreferredSize(new Dimension(600, 300)); frame.pack(); frame.setLocation(50, 100); frame.setDefaultCloseOperation(JFrame.EXIT_ON_CLOSE); RepaintManager.setCurrentManager(new RepaintManager() { @Override public void addDirtyRegion(JComponent c, int x, int y, int w, int h) { Container con = c.getParent(); while (con instanceof JComponent) { if (!con.isVisible()) { return; } if (con instanceof GradientViewPort) { c = (JComponent) con; x = 0; y = 0; w = con.getWidth(); h = con.getHeight(); } con = con.getParent(); } super.addDirtyRegion(c, x, y, w, h); } }); frame.setVisible(true); start(); } private void start() { timer = new javax.swing.Timer(100, updateCol()); timer.start(); } public Action updateCol() { return new AbstractAction("text load action") { private static final long serialVersionUID = 1L; @Override public void actionPerformed(ActionEvent e) { System.out.println("updating row " + (count + 1)); TableModel model = table.getModel(); int cols = model.getColumnCount(); int row = 0; for (int j = 0; j < cols; j++) { row = count; table.changeSelection(row, 0, false, false); timer.setDelay(100); Object value = "row " + (count + 1) + " item " + (j + 1); model.setValueAt(value, count, j); } count++; if (count >= table.getRowCount()) { timer.stop(); table.changeSelection(0, 0, false, false); java.awt.EventQueue.invokeLater(new Runnable() { @Override public void run() { table.clearSelection(); } }); } } }; } public static void main(String[] args) { java.awt.EventQueue.invokeLater(new Runnable() { @Override public void run() { ViewPortFlickering viewPortFlickering = new ViewPortFlickering(); } }); } } class GradientViewPort extends JScrollPane { private static final long serialVersionUID = 1L; private final int h = 50; private BufferedImage img = null; private BufferedImage shadow = new BufferedImage(1, h, BufferedImage.TYPE_INT_ARGB); private JViewport viewPort; public GradientViewPort(JComponent com) { super(com); viewPort = this.getViewport(); viewPort.setScrollMode(JViewport.BLIT_SCROLL_MODE); viewPort.setScrollMode(JViewport.BACKINGSTORE_SCROLL_MODE); viewPort.setScrollMode(JViewport.SIMPLE_SCROLL_MODE); Graphics2D g2 = shadow.createGraphics(); g2.setPaint(new Color(250, 150, 150)); g2.fillRect(0, 0, 1, h); g2.setComposite(AlphaComposite.DstIn); g2.setPaint(new GradientPaint(0, 0, new Color(0, 0, 0, 0f), 0, h, new Color(0.5f, 0.8f, 0.8f, 0.5f))); g2.fillRect(0, 0, 1, h); g2.dispose(); } @Override public void paint(Graphics g) { if (img == null || img.getWidth() != getWidth() || img.getHeight() != getHeight()) { img = new BufferedImage(getWidth(), getHeight(), BufferedImage.TYPE_INT_ARGB); } Graphics2D g2 = img.createGraphics(); super.paint(g2); Rectangle bounds = getViewport().getVisibleRect(); g2.scale(bounds.getWidth(), -1); int y = (getColumnHeader() == null) ? 0 : getColumnHeader().getHeight(); g2.drawImage(shadow, bounds.x, -bounds.y - y - h, null); g2.scale(1, -1); g2.drawImage(shadow, bounds.x, bounds.y + bounds.height - h + y, null); g2.dispose(); g.drawImage(img, 0, 0, null); } }

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How to generalize a method call in Java (to avoid code duplication)

- by dln385

I have a process that needs to call a method and return its value. However, there are several different methods that this process may need to call, depending on the situation. If I could pass the method and its arguments to the process (like in Python), then this would be no problem. However, I don't know of any way to do this in Java. Here's a concrete example. (This example uses Apache ZooKeeper, but you don't need to know anything about ZooKeeper to understand the example.) The ZooKeeper object has several methods that will fail if the network goes down. In this case, I always want to retry the method. To make this easy, I made a "BetterZooKeeper" class that inherits the ZooKeeper class, and all of its methods automatically retry on failure. This is what the code looked like: public class BetterZooKeeper extends ZooKeeper { private void waitForReconnect() { // logic } @Override public Stat exists(String path, Watcher watcher) { while (true) { try { return super.exists(path, watcher); } catch (KeeperException e) { // We will retry. } waitForReconnect(); } } @Override public byte[] getData(String path, boolean watch, Stat stat) { while (true) { try { return super.getData(path, watch, stat); } catch (KeeperException e) { // We will retry. } waitForReconnect(); } } @Override public void delete(String path, int version) { while (true) { try { super.delete(path, version); return; } catch (KeeperException e) { // We will retry. } waitForReconnect(); } } } (In the actual program there is much more logic and many more methods that I took out of the example for simplicity.) We can see that I'm using the same retry logic, but the arguments, method call, and return type are all different for each of the methods. Here's what I did to eliminate the duplication of code: public class BetterZooKeeper extends ZooKeeper { private void waitForReconnect() { // logic } @Override public Stat exists(final String path, final Watcher watcher) { return new RetryableZooKeeperAction<Stat>() { @Override public Stat action() { return BetterZooKeeper.super.exists(path, watcher); } }.run(); } @Override public byte[] getData(final String path, final boolean watch, final Stat stat) { return new RetryableZooKeeperAction<byte[]>() { @Override public byte[] action() { return BetterZooKeeper.super.getData(path, watch, stat); } }.run(); } @Override public void delete(final String path, final int version) { new RetryableZooKeeperAction<Object>() { @Override public Object action() { BetterZooKeeper.super.delete(path, version); return null; } }.run(); return; } private abstract class RetryableZooKeeperAction<T> { public abstract T action(); public final T run() { while (true) { try { return action(); } catch (KeeperException e) { // We will retry. } waitForReconnect(); } } } } The RetryableZooKeeperAction is parameterized with the return type of the function. The run() method holds the retry logic, and the action() method is a placeholder for whichever ZooKeeper method needs to be run. Each of the public methods of BetterZooKeeper instantiates an anonymous inner class that is a subclass of the RetryableZooKeeperAction inner class, and it overrides the action() method. The local variables are (strangely enough) implicitly passed to the action() method, which is possible because they are final. In the end, this approach does work and it does eliminate the duplication of the retry logic. However, it has two major drawbacks: (1) it creates a new object every time a method is called, and (2) it's ugly and hardly readable. Also I had to workaround the 'delete' method which has a void return value. So, here is my question: is there a better way to do this in Java? This can't be a totally uncommon task, and other languages (like Python) make it easier by allowing methods to be passed. I suspect there might be a way to do this through reflection, but I haven't been able to wrap my head around it.

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How can I make the storage of C++ lambda objects more efficient?

- by Peter Ruderman

I've been thinking about storing C++ lambda's lately. The standard advice you see on the Internet is to store the lambda in a std::function object. However, none of this advice ever considers the storage implications. It occurred to me that there must be some seriously black voodoo going on behind the scenes to make this work. Consider the following class that stores an integer value: class Simple { public: Simple( int value ) { puts( "Constructing simple!" ); this->value = value; } Simple( const Simple& rhs ) { puts( "Copying simple!" ); this->value = rhs.value; } Simple( Simple&& rhs ) { puts( "Moving simple!" ); this->value = rhs.value; } ~Simple() { puts( "Destroying simple!" ); } int Get() const { return this->value; } private: int value; }; Now, consider this simple program: int main() { Simple test( 5 ); std::function<int ()> f = [test] () { return test.Get(); }; printf( "%d\n", f() ); } This is the output I would hope to see from this program: Constructing simple! Copying simple! Moving simple! Destroying simple! 5 Destroying simple! Destroying simple! First, we create the value test. We create a local copy on the stack for the temporary lambda object. We then move the temporary lambda object into memory allocated by std::function. We destroy the temporary lambda. We print our output. We destroy the std::function. And finally, we destroy the test object. Needless to say, this is not what I see. When I compile this on Visual C++ 2010 (release or debug mode), I get this output: Constructing simple! Copying simple! Copying simple! Copying simple! Copying simple! Destroying simple! Destroying simple! Destroying simple! 5 Destroying simple! Destroying simple! Holy crap that's inefficient! Not only did the compiler fail to use my move constructor, but it generated and destroyed two apparently superfluous copies of the lambda during the assignment. So, here finally are the questions: (1) Is all this copying really necessary? (2) Is there some way to coerce the compiler into generating better code? Thanks for reading!

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Login or Register (Ruby on rails)

- by DanielZ

Hello stackoverflow, I'm working on an Ruby on Rails application (2.3.x) and i want to make a form that lets the user login or register. I want to do this in the same form. I have a JS function that replaces the form elements like this: Login form: <% form_for @user do |f| %> <div id="form"> <%= f.label :email, "E-mail" %> <%= f.text_field :email %> <%= f.label :password, "Password" %> <%= f.password_field :password %> <%= link_to "I don't have an account, "#", :id => "changeForm"%> <%= f.submit "Login" %> </div> <% end %> The id "changeForm" triggers a JS function that changes the form elements. So if you press the url the html looks like this: <% form_for @user do |f| %> <div id="form"> <%= f.label :name, "Name" %> <%= f.text_field :name %> <%= f.label :email, "E-mail" %> <%= f.text_field :email %> <%= f.label :password, "Password" %> <%= f.password_field :password %> <%= f.label :password_confirmation, "Password confirmation" %> <%= f.password_field :password_confirmation %> <%= link_to "I do have an account, "#", :id => "changeForm"%> <%= f.submit "Register" %> </div> <% end %> I added the neccesary validations to my user model: class User < ActiveRecord::Base attr_reader :password validates_presence_of :name, :email, :password validates_format_of :email, :with => /\A([^@\s]+)@((?:[-a-z0-9]+\.)+[a-z]{2,})\Z/i validates_confirmation_of :password But what happens when you fill in the email / password you get the errors that the name is missing and that the password fields aren't confirmed. So i could do some nasty programming in my user model like this: #if password_conf or the name are present the user has tried to register... if params[:user][:password_confirmation].present? || params[:user][:name].present? #so we'll try to save the user if @user.save #if the user is saved authenticate the user current_session.user = User.authenticate(params[:user]) #if the user is logged in? if current_session.user.present? flash[:notice] = "succesvully logged redirect_to some_routes_path else #not logged in... flash[:notice] = "Not logged in" render :action => "new" end else #user not saved render :action => "new" end else #So if the params[:user][:password_confirmation] or [:user][:name] weren't present we geuss the user wants to login... current_session.user = User.authenticate(params[:user]) #are we logged_in? if current_session.user.present? flash[:notice] = "Succesvully logged in" redirect_to some_routes_path else #errors toevoegen @user.errors.add(:email, "The combination of email/password isn't valid") @user.errors.add(:password," ") render :action => "new" end end end Without validations this (imho dirty code and should not be in the controller) works. But i want to use the validates_presence_of methods and i don't want to slap the "conventions over configurations" in the face. So another thing i have tried is adding a hidden field to the form: #login form <%= f.hidden_field :login, :value => true %> # and ofcourse set it to false if we want to register. And then i wanted to use the method: before_validation before_validation_on_create do |user| if params[:user].login == true #throws an error i know... validates_presence_of :email, :password validates_format_of :email, :with => /\A([^@\s]+)@((?:[-a-z0-9]+\.)+[a-z]{2,})\Z/i else validates_presence_of :name, :email, :password validates_format_of :email, :with => /\A([^@\s]+)@((?:[-a-z0-9]+\.)+[a-z]{2,})\Z/i validates_confirmation_of :password end end But this doesn't work because i can't access the params. And login isn't a attribute for the user object. But i thought that in this way i could validate the email and password params if the user wants to login. And all the other attrs if the user want to register. So all i could think of doesn't work how i want it to work. So my main goal is this: 1 form for login/register with the use of the validation methods in the user model. So if we want to login but don't fill in any information = give validation errors. And if the user wants to login but the email/password combination doens't match give the "@user.errors.add(:email, "the combination wasn't found in the db...")". And the same goes for user register... Thanks in advance!

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Why one loop is performing better than other memory wise as well as performance wise?

- by Mohit

I have following two loops in C#, and I am running these loops for a collection with 10,000 records being downloaded with paging using "yield return" First foreach(var k in collection) { repo.Save(k); } Second var collectionEnum = collection.GetEnumerator(); while (collectionEnum.MoveNext()) { var k = collectionEnum.Current; repo.Save(k); k = null; } Seems like that the second loop consumes less memory and it faster than the first loop. Memory I understand may be because of k being set to null(Even though I am not sure). But how come it is faster than for each. Following is the actual code [Test] public void BechmarkForEach_Test() { bool isFirstTimeSync = true; Func<Contact, bool> afterProcessing = contactItem => { return true; }; var contactService = CreateSerivce("/administrator/components/com_civicrm"); var contactRepo = new ContactRepository(new Mock<ILogger>().Object); contactRepo.Drop(); contactRepo = new ContactRepository(new Mock<ILogger>().Object); Profile("For Each Profiling",1,()=>{ var localenumertaor=contactService.Download(); foreach (var item in localenumertaor) { if (isFirstTimeSync) item.StateFlag = 1; item.ClientTimeStamp = DateTime.UtcNow; if (item.StateFlag == 1) contactRepo.Insert(item); else contactRepo.Update(item); afterProcessing(item); } contactRepo.DeleteAll(); }); } [Test] public void BechmarkWhile_Test() { bool isFirstTimeSync = true; Func<Contact, bool> afterProcessing = contactItem => { return true; }; var contactService = CreateSerivce("/administrator/components/com_civicrm"); var contactRepo = new ContactRepository(new Mock<ILogger>().Object); contactRepo.Drop(); contactRepo = new ContactRepository(new Mock<ILogger>().Object); var itemsCollection = contactService.Download().GetEnumerator(); Profile("While Profiling", 1, () => { while (itemsCollection.MoveNext()) { var item = itemsCollection.Current; //if First time sync then ignore and overwrite the stateflag if (isFirstTimeSync) item.StateFlag = 1; item.ClientTimeStamp = DateTime.UtcNow; if (item.StateFlag == 1) contactRepo.Insert(item); else contactRepo.Update(item); afterProcessing(item); item = null; } contactRepo.DeleteAll(); }); } static void Profile(string description, int iterations, Action func) { // clean up GC.Collect(); GC.WaitForPendingFinalizers(); GC.Collect(); // warm up func(); var watch = Stopwatch.StartNew(); for (int i = 0; i < iterations; i++) { func(); } watch.Stop(); Console.Write(description); Console.WriteLine(" Time Elapsed {0} ms", watch.ElapsedMilliseconds); } I m using the micro bench marking, from a stackoverflow question itself benchmarking-small-code The time taken is For Each Profiling Time Elapsed 5249 ms While Profiling Time Elapsed 116 ms

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WCF service is not getting called

- by Cheranga

I have a web solution and I have a WCF service project inside it. We need to support "cookieless". so in the web.config, it's set as <sessionState mode="SQLServer" sqlConnectionString="Data Source=ds;Initial Catalog=db;User Id=uid;Password=pwd" allowCustomSqlDatabase="true" cookieless="true" timeout="720" regenerateExpiredSessionId="false"/> The WCF service will be supporting sessions, so we have also set "aspNetCompatibilityEnabled" to true in web.config. <serviceHostingEnvironment aspNetCompatibilityEnabled="true" multipleSiteBindingsEnabled="true"/> The service and interfaces are as follows, [ServiceContract(SessionMode=SessionMode.Allowed)] public interface ICDOCService { } [AspNetCompatibilityRequirements(RequirementsMode = AspNetCompatibilityRequirementsMode.Allowed)] public class CDOCService : ICDOCService { } The problem we are facing is we cannot access the service from any client application. (web app, WCF test client) The following error is showing, when we access it via WCF Test client, Failed to invoke the service. Possible causes: The service is offline or inaccessible; the client-side configuration does not match the proxy; the existing proxy is invalid. Refer to the stack trace for more detail. You can try to recover by starting a new proxy, restoring to default configuration, or refreshing the service. The content type text/html; charset=UTF-8 of the response message does not match the content type of the binding (multipart/related; type="application/xop+xml"). If using a custom encoder, be sure that the IsContentTypeSupported method is implemented properly. The first 1024 bytes of the response were: <HTML> <HEAD> <link rel="alternate" type="text/xml" href="http://localhost:53721/Services/CDOCService.svc?disco"/> <STYLE type="text/css">#content{ FONT-SIZE: 0.7em; PADDING-BOTTOM: 2em; MARGIN-LEFT: 30px}BODY{MARGIN-TOP: 0px; MARGIN-LEFT: 0px; COLOR: #000000; FONT-FAMILY: Verdana; BACKGROUND-COLOR: white}P{MARGIN-TOP: 0px; MARGIN-BOTTOM: 12px; COLOR: #000000; FONT-FAMILY: Verdana}PRE{BORDER-RIGHT: #f0f0e0 1px solid; PADDING-RIGHT: 5px; BORDER-TOP: #f0f0e0 1px solid; MARGIN-TOP: -5px; PADDING-LEFT: 5px; FONT-SIZE: 1.2em; PADDING-BOTTOM: 5px; BORDER-LEFT: #f0f0e0 1px solid; PADDING-TOP: 5px; BORDER-BOTTOM: #f0f0e0 1px solid; FONT-FAMILY: Courier New; BACKGROUND-COLOR: #e5e5cc}.heading1{MARGIN-TOP: 0px; PADDING-LEFT: 15px; FONT-WEIGHT: normal; FONT-SIZE: 26px; MARGIN-BOTTOM: 0px; PADDING-BOTTOM: 3px; MARGIN-LEFT: -30px; WIDTH: 100%; COLOR: #ffffff; PADDING-TOP: 10px; FONT-FAMILY: Tahoma; BACKGROUND-COLOR: #003366}.intro{MARGIN-LEFT: -15px} </STYLE> <TITLE>CDOCService Service</TITLE></HEAD><BODY><DIV id="content"><P '. Server stack trace: at System.ServiceModel.Channels.HttpChannelUtilities.ValidateRequestReplyResponse(HttpWebRequest request, HttpWebResponse response, HttpChannelFactory factory, WebException responseException, ChannelBinding channelBinding) at System.ServiceModel.Channels.HttpChannelFactory.HttpRequestChannel.HttpChannelRequest.WaitForReply(TimeSpan timeout) at System.ServiceModel.Channels.RequestChannel.Request(Message message, TimeSpan timeout) at System.ServiceModel.Dispatcher.RequestChannelBinder.Request(Message message, TimeSpan timeout) at System.ServiceModel.Channels.ServiceChannel.Call(String action, Boolean oneway, ProxyOperationRuntime operation, Object[] ins, Object[] outs, TimeSpan timeout) at System.ServiceModel.Channels.ServiceChannel.Call(String action, Boolean oneway, ProxyOperationRuntime operation, Object[] ins, Object[] outs) at System.ServiceModel.Channels.ServiceChannelProxy.InvokeService(IMethodCallMessage methodCall, ProxyOperationRuntime operation) at System.ServiceModel.Channels.ServiceChannelProxy.Invoke(IMessage message) Exception rethrown at [0]: at System.Runtime.Remoting.Proxies.RealProxy.HandleReturnMessage(IMessage reqMsg, IMessage retMsg) at System.Runtime.Remoting.Proxies.RealProxy.PrivateInvoke(MessageData& msgData, Int32 type) at ICDOCService.GetCDOCCount(String institutionID, String mrnID, String userID, String callingSystemID, String securityToken) at CDOCServiceClient.GetCDOCCount(String institutionID, String mrnID, String userID, String callingSystemID, String securityToken)

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How to define template directives (from an API perspective)?

- by Ralph

Preface I'm writing a template language (don't bother trying to talk me out of it), and in it, there are two kinds of user-extensible nodes. TemplateTags and TemplateDirectives. A TemplateTag closely relates to an HTML tag -- it might look something like div(class="green") { "content" } And it'll be rendered as <div class="green">content</div> i.e., it takes a bunch of attributes, plus some content, and spits out some HTML. TemplateDirectives are a little more complicated. They can be things like for loops, ifs, includes, and other such things. They look a lot like a TemplateTag, but they need to be processed differently. For example, @for($i in $items) { div(class="green") { $i } } Would loop over $items and output the content with the variable $i substituted in each time. So.... I'm trying to decide on a way to define these directives now. Template Tags The TemplateTags are pretty easy to write. They look something like this: [TemplateTag] static string div(string content = null, object attrs = null) { return HtmlTag("div", content, attrs); } Where content gets the stuff between the curly braces (pre-rendered if there are variables in it and such), and attrs is either a Dictionary<string,object> of attributes, or an anonymous type used like a dictionary. It just returns the HTML which gets plunked into its place. Simple! You can write tags in basically 1 line. Template Directives The way I've defined them now looks like this: [TemplateDirective] static string @for(string @params, string content) { var tokens = Regex.Split(@params, @"\sin\s").Select(s => s.Trim()).ToArray(); string itemName = tokens[0].Substring(1); string enumName = tokens[1].Substring(1); var enumerable = data[enumName] as IEnumerable; var sb = new StringBuilder(); var template = new Template(content); foreach (var item in enumerable) { var templateVars = new Dictionary<string, object>(data) { { itemName, item } }; sb.Append(template.Render(templateVars)); } return sb.ToString(); } (Working example). Basically, the stuff between the ( and ) is not split into arguments automatically (like the template tags do), and the content isn't pre-rendered either. The reason it isn't pre-rendered is because you might want to add or remove some template variables or something first. In this case, we add the $i variable to the template variables, var templateVars = new Dictionary<string, object>(data) { { itemName, item } }; And then render the content manually, sb.Append(template.Render(templateVars)); Question I'm wondering if this is the best approach to defining custom Template Directives. I want to make it as easy as possible. What if the user doesn't know how to render templates, or doesn't know that he's supposed to? Maybe I should pass in a Template instance pre-filled with the content instead? Or maybe only let him tamper w/ the template variables, and then automatically render the content at the end? OTOH, for things like "if" if the condition fails, then the template wouldn't need to be rendered at all. So there's a lot of flexibility I need to allow in here. Thoughts?

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SOAP and NHibernate Session in C#

- by Anonymous Coward

In a set of SOAP web services the user is authenticated with custom SOAP header (username/password). Each time the user call a WS the following Auth method is called to authenticate and retrieve User object from NHibernate session: [...] public Services : Base { private User user; [...] public string myWS(string username, string password) { if( Auth(username, password) ) { [...] } } } public Base : WebService { protected static ISessionFactory sesFactory; protected static ISession session; static Base { Configuration conf = new Configuration(); [...] sesFactory = conf.BuildSessionFactory(); } private bool Auth(...) { session = sesFactory.OpenSession(); MembershipUser user = null; if (UserCredentials != null && Membership.ValidateUser(username, password)) { luser = Membership.GetUser(username); } ... try { user = (User)session.Get(typeof(User), luser.ProviderUserKey.ToString()); } catch { user = null; throw new [...] } return user != null; } } When the WS work is done the session is cleaned up nicely and everything works: the WSs create, modify and change objects and Nhibernate save them in the DB. The problems come when an user (same username/password) calls the same WS at same time from different clients (machines). The state of the saved objects are inconsistent. How do I manage the session correctly to avoid this? I searched and the documentation about Session management in NHibernate is really vast. Should I Lock over user object? Should I set up a "session share" management between WS calls from same user? Should I use Transaction in some savvy way? Thanks Update1 Yes, mSession is 'session'. Update2 Even with a non-static session object the data saved in the DB are inconsistent. The pattern I use to insert/save object is the following: var return_value = [...]; try { using(ITransaction tx = session.Transaction) { tx.Begin(); MyType obj = new MyType(); user.field = user.field - obj.field; // The fields names are i.e. but this is actually what happens. session.Save(user); session.Save(obj); tx.Commit(); return_value = obj.another_field; } } catch ([...]) { // Handling exceptions... } finally { // Clean up session.Flush(); session.Close(); } return return_value; All new objects (MyType) are correctly saved but the user.field status is not as I would expect. Even obj.another_field is correct (the field is an ID with generated=on-save policy). It is like 'user.field = user.field - obj.field;' is executed more times then necessary.

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Serious problem with WCF, GridViews, Callbacks and ExecuteReaders exceptions.

- by barjed

Hi, I have this problem that is driving me insane. I have a project to deliver before Thursday. Basically an app consiting of three components that communicate with each other in WCF. I have one console app and one Windows Forms app. The console app is a server that's connected to the database. You can add records to it via the Windows Forms client that connectes with the server through the WCF. The code for the client: namespace BankAdministratorClient { [CallbackBehavior(ConcurrencyMode = ConcurrencyMode.Single, UseSynchronizationContext = false)] public partial class Form1 : Form, BankServverReference.BankServerCallback { private BankServverReference.BankServerClient server = null; private SynchronizationContext interfaceContext = null; public Form1() { InitializeComponent(); interfaceContext = SynchronizationContext.Current; server = new BankServverReference.BankServerClient(new InstanceContext(this), "TcpBinding"); server.Open(); server.Subscribe(); refreshGridView(""); } public void refreshClients(string s) { SendOrPostCallback callback = delegate(object state) { refreshGridView(s); }; interfaceContext.Post(callback, s); } public void refreshGridView(string s) { try { userGrid.DataSource = server.refreshDatabaseConnection().Tables[0]; } catch (Exception ex) { MessageBox.Show(ex.ToString()); } } private void buttonAdd_Click(object sender, EventArgs e) { server.addNewAccount(Int32.Parse(inputPIN.Text), Int32.Parse(inputBalance.Text)); } private void Form1_FormClosing(object sender, FormClosingEventArgs e) { try { server.Unsubscribe(); server.Close(); }catch{} } } } The code for the server: namespace SSRfinal_tcp { class Program { static void Main(string[] args) { Console.WriteLine(MessageHandler.dataStamp("The server is starting up")); using (ServiceHost server = new ServiceHost(typeof(BankServer))) { server.Open(); Console.WriteLine(MessageHandler.dataStamp("The server is running")); Console.ReadKey(); } } } [ServiceBehavior(ConcurrencyMode = ConcurrencyMode.Single, InstanceContextMode = InstanceContextMode.PerCall, IncludeExceptionDetailInFaults = true)] public class BankServer : IBankServerService { private static DatabaseLINQConnectionDataContext database = new DatabaseLINQConnectionDataContext(); private static List<IBankServerServiceCallback> subscribers = new List<IBankServerServiceCallback>(); public void Subscribe() { try { IBankServerServiceCallback callback = OperationContext.Current.GetCallbackChannel<IBankServerServiceCallback>(); if (!subscribers.Contains(callback)) subscribers.Add(callback); Console.WriteLine(MessageHandler.dataStamp("A new Bank Administrator has connected")); } catch { Console.WriteLine(MessageHandler.dataStamp("A Bank Administrator has failed to connect")); } } public void Unsubscribe() { try { IBankServerServiceCallback callback = OperationContext.Current.GetCallbackChannel<IBankServerServiceCallback>(); if (subscribers.Contains(callback)) subscribers.Remove(callback); Console.WriteLine(MessageHandler.dataStamp("A Bank Administrator has been signed out from the connection list")); } catch { Console.WriteLine(MessageHandler.dataStamp("A Bank Administrator has failed to sign out from the connection list")); } } public DataSet refreshDatabaseConnection() { var q = from a in database.GetTable<Account>() select a; DataTable dt = q.toTable(rec => new object[] { q }); DataSet data = new DataSet(); data.Tables.Add(dt); Console.WriteLine(MessageHandler.dataStamp("A Bank Administrator has requested a database data listing refresh")); return data; } public void addNewAccount(int pin, int balance) { Account acc = new Account() { PIN = pin, Balance = balance, IsApproved = false }; database.Accounts.InsertOnSubmit(acc); database.SubmitChanges(); database.addNewAccount(pin, balance, false); subscribers.ForEach(delegate(IBankServerServiceCallback callback) { callback.refreshClients("New operation is pending approval."); }); } } } This is really simple and it works for a single window. However, when you open multiple instances of the client window and try to add a new record, the windows that is performing the insert operation crashes with the ExecuteReader error and the " requires an open and available connection. the connection's current state is connecting" bla bla stuff. I have no idea what's going on. Please advise.

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Basic C question, concerning memory allocation and value assignment

- by VHristov

Hi there, I have recently started working on my master thesis in C that I haven't used in quite a long time. Being used to Java, I'm now facing all kinds of problems all the time. I hope someone can help me with the following one, since I've been struggling with it for the past two days. So I have a really basic model of a database: tables, tuples, attributes and I'm trying to load some data into this structure. Following are the definitions: typedef struct attribute { int type; char * name; void * value; } attribute; typedef struct tuple { int tuple_id; int attribute_count; attribute * attributes; } tuple; typedef struct table { char * name; int row_count; tuple * tuples; } table; Data is coming from a file with inserts (generated for the Wisconsin benchmark), which I'm parsing. I have only integer or string values. A sample row would look like: insert into table values (9205, 541, 1, 1, 5, 5, 5, 5, 0, 1, 9205, 10, 11, 'HHHHHHH', 'HHHHHHH', 'HHHHHHH'); I've "managed" to load and parse the data and also to assign it. However, the assignment bit is buggy, since all values point to the same memory location, i.e. all rows look identical after I've loaded the data. Here is what I do: char value[10]; // assuming no value is longer than 10 chars int i, j, k; table * data = (table*) malloc(sizeof(data)); data->name = "table"; data->row_count = number_of_lines; data->tuples = (tuple*) malloc(number_of_lines*sizeof(tuple)); tuple* current_tuple; for(i=0; i<number_of_lines; i++) { current_tuple = &data->tuples[i]; current_tuple->tuple_id = i; current_tuple->attribute_count = 16; // static in our system current_tuple->attributes = (attribute*) malloc(16*sizeof(attribute)); for(k = 0; k < 16; k++) { current_tuple->attributes[k].name = attribute_names[k]; // for int values: current_tuple->attributes[k].type = DB_ATT_TYPE_INT; // write data into value-field int v = atoi(value); current_tuple->attributes[k].value = &v; // for string values: current_tuple->attributes[k].type = DB_ATT_TYPE_STRING; current_tuple->attributes[k].value = value; } // ... } While I am perfectly aware, why this is not working, I can't figure out how to get it working. I've tried following things, none of which worked: memcpy(current_tuple->attributes[k].value, &v, sizeof(int)); This results in a bad access error. Same for the following code (since I'm not quite sure which one would be the correct usage): memcpy(current_tuple->attributes[k].value, &v, 1); Not even sure if memcpy is what I need here... Also I've tried allocating memory, by doing something like: current_tuple->attributes[k].value = (int *) malloc(sizeof(int)); only to get "malloc: * error for object 0x100108e98: incorrect checksum for freed object - object was probably modified after being freed." As far as I understand this error, memory has already been allocated for this object, but I don't see where this happened. Doesn't the malloc(sizeof(attribute)) only allocate the memory needed to store an integer and two pointers (i.e. not the memory those pointers point to)? Any help would be greatly appreciated! Regards, Vassil

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Do I must expose the aggregate children as public properties to implement the Persistence ignorance?

- by xuehua

Hi all, I'm very glad that i found this website recently, I've learned a lot from here. I'm from China, and my English is not so good. But i will try to express myself what i want to say. Recently, I've started learning about Domain Driven Design, and I'm very interested about it. And I plan to develop a Forum website using DDD. After reading lots of threads from here, I understood that persistence ignorance is a good practice. Currently, I have two questions about what I'm thinking for a long time. Should the domain object interact with repository to get/save data? If the domain object doesn't use repository, then how does the Infrastructure layer (like unit of work) know which domain object is new/modified/removed? For the second question. There's an example code: Suppose i have a user class: public class User { public Guid Id { get; set; } public string UserName { get; set; } public string NickName { get; set; } /// <summary> /// A Roles collection which represents the current user's owned roles. /// But here i don't want to use the public property to expose it. /// Instead, i use the below methods to implement. /// </summary> //public IList<Role> Roles { get; set; } private List<Role> roles = new List<Role>(); public IList<Role> GetRoles() { return roles; } public void AddRole(Role role) { roles.Add(role); } public void RemoveRole(Role role) { roles.Remove(role); } } Based on the above User class, suppose i get an user from the IUserRepository, and add an Role for it. IUserRepository userRepository; User user = userRepository.Get(Guid.NewGuid()); user.AddRole(new Role() { Name = "Administrator" }); In this case, i don't know how does the repository or unit of work can know that user has a new role? I think, a real persistence ignorance ORM framework should support POCO, and any changes occurs on the POCO itself, the persistence framework should know automatically. Even if change the object status through the method(AddRole, RemoveRole) like the above example. I know a lot of ORM can automatically persistent the changes if i use the Roles property, but sometimes i don't like this way because of the performance reason. Could anyone give me some ideas for this? Thanks. This is my first question on this site. I hope my English can be understood. Any answers will be very appreciated.

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jQuery .find() doesn't return data in IE but does in Firefox and Chrome

- by Steve Hiner

I helped a friend out by doing a little web work for him. Part of what he needed was an easy way to change a couple pieces of text on his site. Rather than having him edit the HTML I decided to provide an XML file with the messages in it and I used jQuery to pull them out of the file and insert them into the page. It works great... In Firefox and Chrome, not so great in IE7. I was hoping one of you could tell me why. I did a fair but of googling but couldn't find what I'm looking for. Here's the XML: <?xml version="1.0" encoding="utf-8" ?> <messages> <message type="HeaderMessage"> This message is put up in the header area. </message> <message type="FooterMessage"> This message is put in the lower left cell. </message> </messages> And here's my jQuery call: <script type="text/javascript"> $(document).ready(function() { $.get('messages.xml', function(d) { //I have confirmed that it gets to here in IE //and it has the xml loaded. //alert(d); gives me a message box with the xml text in it //alert($(d).find('message')); gives me "[object Object]" //alert($(d).find('message')[0]); gives me "undefined" //alert($(d).find('message').Length); gives me "undefined" $(d).find('message').each(function() { //But it never gets to here in IE var $msg = $(this); var type = $msg.attr("type"); var message = $msg.text(); switch (type) { case "HeaderMessage": $("#HeaderMessageDiv").html(message); break; case "FooterMessage": $("#footermessagecell").html(message); break; default: } }); }); }); </script> Is there something I need to do differently in IE? Based on the message box with [object Object] I'm assumed that .find was working in IE but since I can't index into the array with [0] or check it's Length I'm guessing that means .find isn't returning any results. Any reason why that would work perfectly in Firefox and Chrome but fail in IE? I'm a total newbie with jQuery so I hope I haven't just done something stupid. That code above was scraped out of a forum and modified to suit my needs. Since jQuery is cross-platform I figured I wouldn't have to deal with this mess. Edit: I've found that if I load the page in Visual Studio 2008 and run it then it will work in IE. So it turns out it always works when run through the development web server. Now I'm thinking IE just doesn't like doing .find in XML loaded off of my local drive so maybe when this is on an actual web server it will work OK. I have confirmed that it works fine when browsed from a web server. Must be a peculiarity with IE. I'm guessing it's because the web server sets the mime type for the xml data file transfer and without that IE doesn't parse the xml correctly.

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Is there a Telecommunications Reference Architecture?

- by raul.goycoolea

@font-face { font-family: "Arial"; }@font-face { font-family: "Courier New"; }@font-face { font-family: "Wingdings"; }@font-face { font-family: "Cambria"; }p.MsoNormal, li.MsoNormal, div.MsoNormal { margin: 0cm 0cm 0.0001pt; font-size: 12pt; font-family: "Times New Roman"; }p.MsoListParagraph, li.MsoListParagraph, div.MsoListParagraph { margin: 0cm 0cm 0.0001pt 36pt; font-size: 12pt; font-family: "Times New Roman"; }p.MsoListParagraphCxSpFirst, li.MsoListParagraphCxSpFirst, div.MsoListParagraphCxSpFirst { margin: 0cm 0cm 0.0001pt 36pt; font-size: 12pt; font-family: "Times New Roman"; }p.MsoListParagraphCxSpMiddle, li.MsoListParagraphCxSpMiddle, div.MsoListParagraphCxSpMiddle { margin: 0cm 0cm 0.0001pt 36pt; font-size: 12pt; font-family: "Times New Roman"; }p.MsoListParagraphCxSpLast, li.MsoListParagraphCxSpLast, div.MsoListParagraphCxSpLast { margin: 0cm 0cm 0.0001pt 36pt; font-size: 12pt; font-family: "Times New Roman"; }div.Section1 { page: Section1; }ol { margin-bottom: 0cm; }ul { margin-bottom: 0cm; } Abstract Reference architecture provides needed architectural information that can be provided in advance to an enterprise to enable consistent architectural best practices. Enterprise Reference Architecture helps business owners to actualize their strategies, vision, objectives, and principles. It evaluates the IT systems, based on Reference Architecture goals, principles, and standards. It helps to reduce IT costs by increasing functionality, availability, scalability, etc. Telecom Reference Architecture provides customers with the flexibility to view bundled service bills online with the provision of multiple services. It provides real-time, flexible billing and charging systems, to handle complex promotions, discounts, and settlements with multiple parties. This paper attempts to describe the Reference Architecture for the Telecom Enterprises. It lays the foundation for a Telecom Reference Architecture by articulating the requirements, drivers, and pitfalls for telecom service providers. It describes generic reference architecture for telecom enterprises and moves on to explain how to achieve Enterprise Reference Architecture by using SOA. Introduction A Reference Architecture provides a methodology, set of practices, template, and standards based on a set of successful solutions implemented earlier. These solutions have been generalized and structured for the depiction of both a logical and a physical architecture, based on the harvesting of a set of patterns that describe observations in a number of successful implementations. It helps as a reference for the various architectures that an enterprise can implement to solve various problems. It can be used as the starting point or the point of comparisons for various departments/business entities of a company, or for the various companies for an enterprise. It provides multiple views for multiple stakeholders. Major artifacts of the Enterprise Reference Architecture are methodologies, standards, metadata, documents, design patterns, etc. Purpose of Reference Architecture In most cases, architects spend a lot of time researching, investigating, defining, and re-arguing architectural decisions. It is like reinventing the wheel as their peers in other organizations or even the same organization have already spent a lot of time and effort defining their own architectural practices. This prevents an organization from learning from its own experiences and applying that knowledge for increased effectiveness. Reference architecture provides missing architectural information that can be provided in advance to project team members to enable consistent architectural best practices. Enterprise Reference Architecture helps an enterprise to achieve the following at the abstract level: · Reference architecture is more of a communication channel to an enterprise · Helps the business owners to accommodate to their strategies, vision, objectives, and principles. · Evaluates the IT systems based on Reference Architecture Principles · Reduces IT spending through increasing functionality, availability, scalability, etc · A Real-time Integration Model helps to reduce the latency of the data updates Is used to define a single source of Information · Provides a clear view on how to manage information and security · Defines the policy around the data ownership, product boundaries, etc. · Helps with cost optimization across project and solution portfolios by eliminating unused or duplicate investments and assets · Has a shorter implementation time and cost Once the reference architecture is in place, the set of architectural principles, standards, reference models, and best practices ensure that the aligned investments have the greatest possible likelihood of success in both the near term and the long term (TCO). Common pitfalls for Telecom Service Providers Telecom Reference Architecture serves as the first step towards maturity for a telecom service provider. During the course of our assignments/experiences with telecom players, we have come across the following observations – Some of these indicate a lack of maturity of the telecom service provider: · In markets that are growing and not so mature, it has been observed that telcos have a significant amount of in-house or home-grown applications. In some of these markets, the growth has been so rapid that IT has been unable to cope with business demands. Telcos have shown a tendency to come up with workarounds in their IT applications so as to meet business needs. · Even for core functions like provisioning or mediation, some telcos have tried to manage with home-grown applications. · Most of the applications do not have the required scalability or maintainability to sustain growth in volumes or functionality. · Applications face interoperability issues with other applications in the operator's landscape. Integrating a new application or network element requires considerable effort on the part of the other applications. · Application boundaries are not clear, and functionality that is not in the initial scope of that application gets pushed onto it. This results in the development of the multiple, small applications without proper boundaries. · Usage of Legacy OSS/BSS systems, poor Integration across Multiple COTS Products and Internal Systems. Most of the Integrations are developed on ad-hoc basis and Point-to-Point Integration. · Redundancy of the business functions in different applications • Fragmented data across the different applications and no integrated view of the strategic data • Lot of performance Issues due to the usage of the complex integration across OSS and BSS systems However, this is where the maturity of the telecom industry as a whole can be of help. The collaborative efforts of telcos to overcome some of these problems have resulted in bodies like the TM Forum. They have come up with frameworks for business processes, data, applications, and technology for telecom service providers. These could be a good starting point for telcos to clean up their enterprise landscape. Industry Trends in Telecom Reference Architecture Telecom reference architectures are evolving rapidly because telcos are facing business and IT challenges. “The reality is that there probably is no killer application, no silver bullet that the telcos can latch onto to carry them into a 21st Century.... Instead, there are probably hundreds – perhaps thousands – of niche applications.... And the only way to find which of these works for you is to try out lots of them, ramp up the ones that work, and discontinue the ones that fail.” – Martin Creaner President & CTO TM Forum. The following trends have been observed in telecom reference architecture: · Transformation of business structures to align with customer requirements · Adoption of more Internet-like technical architectures. The Web 2.0 concept is increasingly being used. · Virtualization of the traditional operations support system (OSS) · Adoption of SOA to support development of IP-based services · Adoption of frameworks like Service Delivery Platforms (SDPs) and IP Multimedia Subsystem · (IMS) to enable seamless deployment of various services over fixed and mobile networks · Replacement of in-house, customized, and stove-piped OSS/BSS with standards-based COTS products · Compliance with industry standards and frameworks like eTOM, SID, and TAM to enable seamless integration with other standards-based products Drivers of Reference Architecture The drivers of the Reference Architecture are Reference Architecture Goals, Principles, and Enterprise Vision and Telecom Transformation. The details are depicted below diagram. @font-face { font-family: "Cambria"; }p.MsoNormal, li.MsoNormal, div.MsoNormal { margin: 0cm 0cm 0.0001pt; font-size: 12pt; font-family: "Times New Roman"; }p.MsoCaption, li.MsoCaption, div.MsoCaption { margin: 0cm 0cm 10pt; font-size: 9pt; font-family: "Times New Roman"; color: rgb(79, 129, 189); font-weight: bold; }div.Section1 { page: Section1; } Figure 1. Drivers for Reference Architecture @font-face { font-family: "Arial"; }@font-face { font-family: "Courier New"; }@font-face { font-family: "Wingdings"; }@font-face { font-family: "Cambria"; }p.MsoNormal, li.MsoNormal, div.MsoNormal { margin: 0cm 0cm 0.0001pt; font-size: 12pt; font-family: "Times New Roman"; }p.MsoListParagraph, li.MsoListParagraph, div.MsoListParagraph { margin: 0cm 0cm 0.0001pt 36pt; font-size: 12pt; font-family: "Times New Roman"; }p.MsoListParagraphCxSpFirst, li.MsoListParagraphCxSpFirst, div.MsoListParagraphCxSpFirst { margin: 0cm 0cm 0.0001pt 36pt; font-size: 12pt; font-family: "Times New Roman"; }p.MsoListParagraphCxSpMiddle, li.MsoListParagraphCxSpMiddle, div.MsoListParagraphCxSpMiddle { margin: 0cm 0cm 0.0001pt 36pt; font-size: 12pt; font-family: "Times New Roman"; }p.MsoListParagraphCxSpLast, li.MsoListParagraphCxSpLast, div.MsoListParagraphCxSpLast { margin: 0cm 0cm 0.0001pt 36pt; font-size: 12pt; font-family: "Times New Roman"; }div.Section1 { page: Section1; }ol { margin-bottom: 0cm; }ul { margin-bottom: 0cm; } Today’s telecom reference architectures should seamlessly integrate traditional legacy-based applications and transition to next-generation network technologies (e.g., IP multimedia subsystems). This has resulted in new requirements for flexible, real-time billing and OSS/BSS systems and implications on the service provider’s organizational requirements and structure. Telecom reference architectures are today expected to: · Integrate voice, messaging, email and other VAS over fixed and mobile networks, back end systems · Be able to provision multiple services and service bundles • Deliver converged voice, video and data services · Leverage the existing Network Infrastructure · Provide real-time, flexible billing and charging systems to handle complex promotions, discounts, and settlements with multiple parties. · Support charging of advanced data services such as VoIP, On-Demand, Services (e.g. Video), IMS/SIP Services, Mobile Money, Content Services and IPTV. · Help in faster deployment of new services • Serve as an effective platform for collaboration between network IT and business organizations · Harness the potential of converging technology, networks, devices and content to develop multimedia services and solutions of ever-increasing sophistication on a single Internet Protocol (IP) · Ensure better service delivery and zero revenue leakage through real-time balance and credit management · Lower operating costs to drive profitability Enterprise Reference Architecture The Enterprise Reference Architecture (RA) fills the gap between the concepts and vocabulary defined by the reference model and the implementation. Reference architecture provides detailed architectural information in a common format such that solutions can be repeatedly designed and deployed in a consistent, high-quality, supportable fashion. This paper attempts to describe the Reference Architecture for the Telecom Application Usage and how to achieve the Enterprise Level Reference Architecture using SOA. • Telecom Reference Architecture • Enterprise SOA based Reference Architecture Telecom Reference Architecture Tele Management Forum’s New Generation Operations Systems and Software (NGOSS) is an architectural framework for organizing, integrating, and implementing telecom systems. NGOSS is a component-based framework consisting of the following elements: · The enhanced Telecom Operations Map (eTOM) is a business process framework. · The Shared Information Data (SID) model provides a comprehensive information framework that may be specialized for the needs of a particular organization. · The Telecom Application Map (TAM) is an application framework to depict the functional footprint of applications, relative to the horizontal processes within eTOM. · The Technology Neutral Architecture (TNA) is an integrated framework. TNA is an architecture that is sustainable through technology changes. NGOSS Architecture Standards are: · Centralized data · Loosely coupled distributed systems · Application components/re-use · A technology-neutral system framework with technology specific implementations · Interoperability to service provider data/processes · Allows more re-use of business components across multiple business scenarios · Workflow automation The traditional operator systems architecture consists of four layers, · Business Support System (BSS) layer, with focus toward customers and business partners. Manages order, subscriber, pricing, rating, and billing information. · Operations Support System (OSS) layer, built around product, service, and resource inventories. · Networks layer – consists of Network elements and 3rd Party Systems. · Integration Layer – to maximize application communication and overall solution flexibility. Reference architecture for telecom enterprises is depicted below. @font-face { font-family: "Arial"; }@font-face { font-family: "Courier New"; }@font-face { font-family: "Wingdings"; }@font-face { font-family: "Cambria"; }p.MsoNormal, li.MsoNormal, div.MsoNormal { margin: 0cm 0cm 0.0001pt; font-size: 12pt; font-family: "Times New Roman"; }p.MsoCaption, li.MsoCaption, div.MsoCaption { margin: 0cm 0cm 10pt; font-size: 9pt; font-family: "Times New Roman"; color: rgb(79, 129, 189); font-weight: bold; }p.MsoListParagraph, li.MsoListParagraph, div.MsoListParagraph { margin: 0cm 0cm 0.0001pt 36pt; font-size: 12pt; font-family: "Times New Roman"; }p.MsoListParagraphCxSpFirst, li.MsoListParagraphCxSpFirst, div.MsoListParagraphCxSpFirst { margin: 0cm 0cm 0.0001pt 36pt; font-size: 12pt; font-family: "Times New Roman"; }p.MsoListParagraphCxSpMiddle, li.MsoListParagraphCxSpMiddle, div.MsoListParagraphCxSpMiddle { margin: 0cm 0cm 0.0001pt 36pt; font-size: 12pt; font-family: "Times New Roman"; }p.MsoListParagraphCxSpLast, li.MsoListParagraphCxSpLast, div.MsoListParagraphCxSpLast { margin: 0cm 0cm 0.0001pt 36pt; font-size: 12pt; font-family: "Times New Roman"; }div.Section1 { page: Section1; }ol { margin-bottom: 0cm; }ul { margin-bottom: 0cm; } Figure 2. Telecom Reference Architecture The major building blocks of any Telecom Service Provider architecture are as follows: 1. Customer Relationship Management CRM encompasses the end-to-end lifecycle of the customer: customer initiation/acquisition, sales, ordering, and service activation, customer care and support, proactive campaigns, cross sell/up sell, and retention/loyalty. CRM also includes the collection of customer information and its application to personalize, customize, and integrate delivery of service to a customer, as well as to identify opportunities for increasing the value of the customer to the enterprise. The key functionalities related to Customer Relationship Management are · Manage the end-to-end lifecycle of a customer request for products. · Create and manage customer profiles. · Manage all interactions with customers – inquiries, requests, and responses. · Provide updates to Billing and other south bound systems on customer/account related updates such as customer/ account creation, deletion, modification, request bills, final bill, duplicate bills, credit limits through Middleware. · Work with Order Management System, Product, and Service Management components within CRM. · Manage customer preferences – Involve all the touch points and channels to the customer, including contact center, retail stores, dealers, self service, and field service, as well as via any media (phone, face to face, web, mobile device, chat, email, SMS, mail, the customer's bill, etc.). · Support single interface for customer contact details, preferences, account details, offers, customer premise equipment, bill details, bill cycle details, and customer interactions. CRM applications interact with customers through customer touch points like portals, point-of-sale terminals, interactive voice response systems, etc. The requests by customers are sent via fulfillment/provisioning to billing system for ordering processing. 2. Billing and Revenue Management Billing and Revenue Management handles the collection of appropriate usage records and production of timely and accurate bills – for providing pre-bill usage information and billing to customers; for processing their payments; and for performing payment collections. In addition, it handles customer inquiries about bills, provides billing inquiry status, and is responsible for resolving billing problems to the customer's satisfaction in a timely manner. This process grouping also supports prepayment for services. The key functionalities provided by these applications are · To ensure that enterprise revenue is billed and invoices delivered appropriately to customers. · To manage customers’ billing accounts, process their payments, perform payment collections, and monitor the status of the account balance. · To ensure the timely and effective fulfillment of all customer bill inquiries and complaints. · Collect the usage records from mediation and ensure appropriate rating and discounting of all usage and pricing. · Support revenue sharing; split charging where usage is guided to an account different from the service consumer. · Support prepaid and post-paid rating. · Send notification on approach / exceeding the usage thresholds as enforced by the subscribed offer, and / or as setup by the customer. · Support prepaid, post paid, and hybrid (where some services are prepaid and the rest of the services post paid) customers and conversion from post paid to prepaid, and vice versa. · Support different billing function requirements like charge prorating, promotion, discount, adjustment, waiver, write-off, account receivable, GL Interface, late payment fee, credit control, dunning, account or service suspension, re-activation, expiry, termination, contract violation penalty, etc. · Initiate direct debit to collect payment against an invoice outstanding. · Send notification to Middleware on different events; for example, payment receipt, pre-suspension, threshold exceed, etc. Billing systems typically get usage data from mediation systems for rating and billing. They get provisioning requests from order management systems and inquiries from CRM systems. Convergent and real-time billing systems can directly get usage details from network elements. 3. Mediation Mediation systems transform/translate the Raw or Native Usage Data Records into a general format that is acceptable to billing for their rating purposes. The following lists the high-level roles and responsibilities executed by the Mediation system in the end-to-end solution. · Collect Usage Data Records from different data sources – like network elements, routers, servers – via different protocol and interfaces. · Process Usage Data Records – Mediation will process Usage Data Records as per the source format. · Validate Usage Data Records from each source. · Segregates Usage Data Records coming from each source to multiple, based on the segregation requirement of end Application. · Aggregates Usage Data Records based on the aggregation rule if any from different sources. · Consolidates multiple Usage Data Records from each source. · Delivers formatted Usage Data Records to different end application like Billing, Interconnect, Fraud Management, etc. · Generates audit trail for incoming Usage Data Records and keeps track of all the Usage Data Records at various stages of mediation process. · Checks duplicate Usage Data Records across files for a given time window. 4. Fulfillment This area is responsible for providing customers with their requested products in a timely and correct manner. It translates the customer's business or personal need into a solution that can be delivered using the specific products in the enterprise's portfolio. This process informs the customers of the status of their purchase order, and ensures completion on time, as well as ensuring a delighted customer. These processes are responsible for accepting and issuing orders. They deal with pre-order feasibility determination, credit authorization, order issuance, order status and tracking, customer update on customer order activities, and customer notification on order completion. Order management and provisioning applications fall into this category. The key functionalities provided by these applications are · Issuing new customer orders, modifying open customer orders, or canceling open customer orders; · Verifying whether specific non-standard offerings sought by customers are feasible and supportable; · Checking the credit worthiness of customers as part of the customer order process; · Testing the completed offering to ensure it is working correctly; · Updating of the Customer Inventory Database to reflect that the specific product offering has been allocated, modified, or cancelled; · Assigning and tracking customer provisioning activities; · Managing customer provisioning jeopardy conditions; and · Reporting progress on customer orders and other processes to customer. These applications typically get orders from CRM systems. They interact with network elements and billing systems for fulfillment of orders. 5. Enterprise Management This process area includes those processes that manage enterprise-wide activities and needs, or have application within the enterprise as a whole. They encompass all business management processes that · Are necessary to support the whole of the enterprise, including processes for financial management, legal management, regulatory management, process, cost, and quality management, etc.; · Are responsible for setting corporate policies, strategies, and directions, and for providing guidelines and targets for the whole of the business, including strategy development and planning for areas, such as Enterprise Architecture, that are integral to the direction and development of the business; · Occur throughout the enterprise, including processes for project management, performance assessments, cost assessments, etc. (i) Enterprise Risk Management: Enterprise Risk Management focuses on assuring that risks and threats to the enterprise value and/or reputation are identified, and appropriate controls are in place to minimize or eliminate the identified risks. The identified risks may be physical or logical/virtual. Successful risk management ensures that the enterprise can support its mission critical operations, processes, applications, and communications in the face of serious incidents such as security threats/violations and fraud attempts. Two key areas covered in Risk Management by telecom operators are: · Revenue Assurance: Revenue assurance system will be responsible for identifying revenue loss scenarios across components/systems, and will help in rectifying the problems. The following lists the high-level roles and responsibilities executed by the Revenue Assurance system in the end-to-end solution. o Identify all usage information dropped when networks are being upgraded. o Interconnect bill verification. o Identify where services are routinely provisioned but never billed. o Identify poor sales policies that are intensifying collections problems. o Find leakage where usage is sent to error bucket and never billed for. o Find leakage where field service, CRM, and network build-out are not optimized. · Fraud Management: Involves collecting data from different systems to identify abnormalities in traffic patterns, usage patterns, and subscription patterns to report suspicious activity that might suggest fraudulent usage of resources, resulting in revenue losses to the operator. The key roles and responsibilities of the system component are as follows: o Fraud management system will capture and monitor high usage (over a certain threshold) in terms of duration, value, and number of calls for each subscriber. The threshold for each subscriber is decided by the system and fixed automatically. o Fraud management will be able to detect the unauthorized access to services for certain subscribers. These subscribers may have been provided unauthorized services by employees. The component will raise the alert to the operator the very first time of such illegal calls or calls which are not billed. o The solution will be to have an alarm management system that will deliver alarms to the operator/provider whenever it detects a fraud, thus minimizing fraud by catching it the first time it occurs. o The Fraud Management system will be capable of interfacing with switches, mediation systems, and billing systems (ii) Knowledge Management This process focuses on knowledge management, technology research within the enterprise, and the evaluation of potential technology acquisitions. Key responsibilities of knowledge base management are to · Maintain knowledge base – Creation and updating of knowledge base on ongoing basis. · Search knowledge base – Search of knowledge base on keywords or category browse · Maintain metadata – Management of metadata on knowledge base to ensure effective management and search. · Run report generator. · Provide content – Add content to the knowledge base, e.g., user guides, operational manual, etc. (iii) Document Management It focuses on maintaining a repository of all electronic documents or images of paper documents relevant to the enterprise using a system. (iv) Data Management It manages data as a valuable resource for any enterprise. For telecom enterprises, the typical areas covered are Master Data Management, Data Warehousing, and Business Intelligence. It is also responsible for data governance, security, quality, and database management. Key responsibilities of Data Management are · Using ETL, extract the data from CRM, Billing, web content, ERP, campaign management, financial, network operations, asset management info, customer contact data, customer measures, benchmarks, process data, e.g., process inputs, outputs, and measures, into Enterprise Data Warehouse. · Management of data traceability with source, data related business rules/decisions, data quality, data cleansing data reconciliation, competitors data – storage for all the enterprise data (customer profiles, products, offers, revenues, etc.) · Get online update through night time replication or physical backup process at regular frequency. · Provide the data access to business intelligence and other systems for their analysis, report generation, and use. (v) Business Intelligence It uses the Enterprise Data to provide the various analysis and reports that contain prospects and analytics for customer retention, acquisition of new customers due to the offers, and SLAs. It will generate right and optimized plans – bolt-ons for the customers. The following lists the high-level roles and responsibilities executed by the Business Intelligence system at the Enterprise Level: · It will do Pattern analysis and reports problem. · It will do Data Analysis – Statistical analysis, data profiling, affinity analysis of data, customer segment wise usage patterns on offers, products, service and revenue generation against services and customer segments. · It will do Performance (business, system, and forecast) analysis, churn propensity, response time, and SLAs analysis. · It will support for online and offline analysis, and report drill down capability. · It will collect, store, and report various SLA data. · It will provide the necessary intelligence for marketing and working on campaigns, etc., with cost benefit analysis and predictions. It will advise on customer promotions with additional services based on loyalty and credit history of customer · It will Interface with Enterprise Data Management system for data to run reports and analysis tasks. It will interface with the campaign schedules, based on historical success evidence. (vi) Stakeholder and External Relations Management It manages the enterprise's relationship with stakeholders and outside entities. Stakeholders include shareholders, employee organizations, etc. Outside entities include regulators, local community, and unions. Some of the processes within this grouping are Shareholder Relations, External Affairs, Labor Relations, and Public Relations. (vii) Enterprise Resource Planning It is used to manage internal and external resources, including tangible assets, financial resources, materials, and human resources. Its purpose is to facilitate the flow of information between all business functions inside the boundaries of the enterprise and manage the connections to outside stakeholders. ERP systems consolidate all business operations into a uniform and enterprise wide system environment. The key roles and responsibilities for Enterprise System are given below: · It will handle responsibilities such as core accounting, financial, and management reporting. · It will interface with CRM for capturing customer account and details. · It will interface with billing to capture the billing revenue and other financial data. · It will be responsible for executing the dunning process. Billing will send the required feed to ERP for execution of dunning. · It will interface with the CRM and Billing through batch interfaces. Enterprise management systems are like horizontals in the enterprise and typically interact with all major telecom systems. E.g., an ERP system interacts with CRM, Fulfillment, and Billing systems for different kinds of data exchanges. 6. External Interfaces/Touch Points The typical external parties are customers, suppliers/partners, employees, shareholders, and other stakeholders. External interactions from/to a Service Provider to other parties can be achieved by a variety of mechanisms, including: · Exchange of emails or faxes · Call Centers · Web Portals · Business-to-Business (B2B) automated transactions These applications provide an Internet technology driven interface to external parties to undertake a variety of business functions directly for themselves. These can provide fully or partially automated service to external parties through various touch points. Typical characteristics of these touch points are · Pre-integrated self-service system, including stand-alone web framework or integration front end with a portal engine · Self services layer exposing atomic web services/APIs for reuse by multiple systems across the architectural environment · Portlets driven connectivity exposing data and services interoperability through a portal engine or web application These touch points mostly interact with the CRM systems for requests, inquiries, and responses. 7. Middleware The component will be primarily responsible for integrating the different systems components under a common platform. It should provide a Standards-Based Platform for building Service Oriented Architecture and Composite Applications. The following lists the high-level roles and responsibilities executed by the Middleware component in the end-to-end solution. · As an integration framework, covering to and fro interfaces · Provide a web service framework with service registry. · Support SOA framework with SOA service registry. · Each of the interfaces from / to Middleware to other components would handle data transformation, translation, and mapping of data points. · Receive data from the caller / activate and/or forward the data to the recipient system in XML format. · Use standard XML for data exchange. · Provide the response back to the service/call initiator. · Provide a tracking until the response completion. · Keep a store transitional data against each call/transaction. · Interface through Middleware to get any information that is possible and allowed from the existing systems to enterprise systems; e.g., customer profile and customer history, etc. · Provide the data in a common unified format to the SOA calls across systems, and follow the Enterprise Architecture directive. · Provide an audit trail for all transactions being handled by the component. 8. Network Elements The term Network Element means a facility or equipment used in the provision of a telecommunications service. Such terms also includes features, functions, and capabilities that are provided by means of such facility or equipment, including subscriber numbers, databases, signaling systems, and information sufficient for billing and collection or used in the transmission, routing, or other provision of a telecommunications service. Typical network elements in a GSM network are Home Location Register (HLR), Intelligent Network (IN), Mobile Switching Center (MSC), SMS Center (SMSC), and network elements for other value added services like Push-to-talk (PTT), Ring Back Tone (RBT), etc. Network elements are invoked when subscribers use their telecom devices for any kind of usage. These elements generate usage data and pass it on to downstream systems like mediation and billing system for rating and billing. They also integrate with provisioning systems for order/service fulfillment. 9. 3rd Party Applications 3rd Party systems are applications like content providers, payment gateways, point of sale terminals, and databases/applications maintained by the Government. Depending on applicability and the type of functionality provided by 3rd party applications, the integration with different telecom systems like CRM, provisioning, and billing will be done. 10. Service Delivery Platform A service delivery platform (SDP) provides the architecture for the rapid deployment, provisioning, execution, management, and billing of value added telecom services. SDPs are based on the concept of SOA and layered architecture. They support the delivery of voice, data services, and content in network and device-independent fashion. They allow application developers to aggregate network capabilities, services, and sources of content. SDPs typically contain layers for web services exposure, service application development, and network abstraction. SOA Reference Architecture SOA concept is based on the principle of developing reusable business service and building applications by composing those services, instead of building monolithic applications in silos. It’s about bridging the gap between business and IT through a set of business-aligned IT services, using a set of design principles, patterns, and techniques. In an SOA, resources are made available to participants in a value net, enterprise, line of business (typically spanning multiple applications within an enterprise or across multiple enterprises). It consists of a set of business-aligned IT services that collectively fulfill an organization’s business processes and goals. We can choreograph these services into composite applications and invoke them through standard protocols. SOA, apart from agility and reusability, enables: · The business to specify processes as orchestrations of reusable services · Technology agnostic business design, with technology hidden behind service interface · A contractual-like interaction between business and IT, based on service SLAs · Accountability and governance, better aligned to business services · Applications interconnections untangling by allowing access only through service interfaces, reducing the daunting side effects of change · Reduced pressure to replace legacy and extended lifetime for legacy applications, through encapsulation in services · A Cloud Computing paradigm, using web services technologies, that makes possible service outsourcing on an on-demand, utility-like, pay-per-usage basis The following section represents the Reference Architecture of logical view for the Telecom Solution. The new custom built application needs to align with this logical architecture in the long run to achieve EA benefits. Packaged implementation applications, such as ERP billing applications, need to expose their functions as service providers (as other applications consume) and interact with other applications as service consumers. COT applications need to expose services through wrappers such as adapters to utilize existing resources and at the same time achieve Enterprise Architecture goal and objectives. The following are the various layers for Enterprise level deployment of SOA. This diagram captures the abstract view of Enterprise SOA layers and important components of each layer. Layered architecture means decomposition of services such that most interactions occur between adjacent layers. However, there is no strict rule that top layers should not directly communicate with bottom layers. The diagram below represents the important logical pieces that would result from overall SOA transformation. @font-face { font-family: "Arial"; }@font-face { font-family: "Courier New"; }@font-face { font-family: "Wingdings"; }@font-face { font-family: "Cambria"; }p.MsoNormal, li.MsoNormal, div.MsoNormal { margin: 0cm 0cm 0.0001pt; font-size: 12pt; font-family: "Times New Roman"; }p.MsoCaption, li.MsoCaption, div.MsoCaption { margin: 0cm 0cm 10pt; font-size: 9pt; font-family: "Times New Roman"; color: rgb(79, 129, 189); font-weight: bold; }p.MsoListParagraph, li.MsoListParagraph, div.MsoListParagraph { margin: 0cm 0cm 0.0001pt 36pt; font-size: 12pt; font-family: "Times New Roman"; }p.MsoListParagraphCxSpFirst, li.MsoListParagraphCxSpFirst, div.MsoListParagraphCxSpFirst { margin: 0cm 0cm 0.0001pt 36pt; font-size: 12pt; font-family: "Times New Roman"; }p.MsoListParagraphCxSpMiddle, li.MsoListParagraphCxSpMiddle, div.MsoListParagraphCxSpMiddle { margin: 0cm 0cm 0.0001pt 36pt; font-size: 12pt; font-family: "Times New Roman"; }p.MsoListParagraphCxSpLast, li.MsoListParagraphCxSpLast, div.MsoListParagraphCxSpLast { margin: 0cm 0cm 0.0001pt 36pt; font-size: 12pt; font-family: "Times New Roman"; }div.Section1 { page: Section1; }ol { margin-bottom: 0cm; }ul { margin-bottom: 0cm; } Figure 3. Enterprise SOA Reference Architecture 1. Operational System Layer: This layer consists of all packaged applications like CRM, ERP, custom built applications, COTS based applications like Billing, Revenue Management, Fulfilment, and the Enterprise databases that are essential and contribute directly or indirectly to the Enterprise OSS/BSS Transformation. ERP holds the data of Asset Lifecycle Management, Supply Chain, and Advanced Procurement and Human Capital Management, etc. CRM holds the data related to Order, Sales, and Marketing, Customer Care, Partner Relationship Management, Loyalty, etc. Content Management handles Enterprise Search and Query. Billing application consists of the following components: · Collections Management, Customer Billing Management, Invoices, Real-Time Rating, Discounting, and Applying of Charges · Enterprise databases will hold both the application and service data, whether structured or unstructured. MDM - Master data majorly consists of Customer, Order, Product, and Service Data. 2. Enterprise Component Layer: This layer consists of the Application Services and Common Services that are responsible for realizing the functionality and maintaining the QoS of the exposed services. This layer uses container-based technologies such as application servers to implement the components, workload management, high availability, and load balancing. Application Services: This Service Layer enables application, technology, and database abstraction so that the complex accessing logic is hidden from the other service layers. This is a basic service layer, which exposes application functionalities and data as reusable services. The three types of the Application access services are: · Application Access Service: This Service Layer exposes application level functionalities as a reusable service between BSS to BSS and BSS to OSS integration. This layer is enabled using disparate technology such as Web Service, Integration Servers, and Adaptors, etc. · Data Access Service: This Service Layer exposes application data services as a reusable reference data service. This is done via direct interaction with application data. and provides the federated query. · Network Access Service: This Service Layer exposes provisioning layer as a reusable service from OSS to OSS integration. This integration service emphasizes the need for high performance, stateless process flows, and distributed design. Common Services encompasses management of structured, semi-structured, and unstructured data such as information services, portal services, interaction services, infrastructure services, and security services, etc. 3. Integration Layer: This consists of service infrastructure components like service bus, service gateway for partner integration, service registry, service repository, and BPEL processor. Service bus will carry the service invocation payloads/messages between consumers and providers. The other important functions expected from it are itinerary based routing, distributed caching of routing information, transformations, and all qualities of service for messaging-like reliability, scalability, and availability, etc. Service registry will hold all contracts (wsdl) of services, and it helps developers to locate or discover service during design time or runtime. • BPEL processor would be useful in orchestrating the services to compose a complex business scenario or process. • Workflow and business rules management are also required to support manual triggering of certain activities within business process. based on the rules setup and also the state machine information. Application, data, and service mediation layer typically forms the overall composite application development framework or SOA Framework. 4. Business Process Layer: These are typically the intermediate services layer and represent Shared Business Process Services. At Enterprise Level, these services are from Customer Management, Order Management, Billing, Finance, and Asset Management application domains. 5. Access Layer: This layer consists of portals for Enterprise and provides a single view of Enterprise information management and dashboard services. 6. Channel Layer: This consists of various devices; applications that form part of extended enterprise; browsers through which users access the applications. 7. Client Layer: This designates the different types of users accessing the enterprise applications. The type of user typically would be an important factor in determining the level of access to applications. 8. Vertical pieces like management, monitoring, security, and development cut across all horizontal layers Management and monitoring involves all aspects of SOA-like services, SLAs, and other QoS lifecycle processes for both applications and services surrounding SOA governance. 9. EA Governance, Reference Architecture, Roadmap, Principles, and Best Practices: EA Governance is important in terms of providing the overall direction to SOA implementation within the enterprise. This involves board-level involvement, in addition to business and IT executives. At a high level, this involves managing the SOA projects implementation, managing SOA infrastructure, and controlling the entire effort through all fine-tuned IT processes in accordance with COBIT (Control Objectives for Information Technology). Devising tools and techniques to promote reuse culture, and the SOA way of doing things needs competency centers to be established in addition to training the workforce to take up new roles that are suited to SOA journey. Conclusions Reference Architectures can serve as the basis for disparate architecture efforts throughout the organization, even if they use different tools and technologies. Reference architectures provide best practices and approaches in the independent way a vendor deals with technology and standards. Reference Architectures model the abstract architectural elements for an enterprise independent of the technologies, protocols, and products that are used to implement an SOA. Telecom enterprises today are facing significant business and technology challenges due to growing competition, a multitude of services, and convergence. Adopting architectural best practices could go a long way in meeting these challenges. The use of SOA-based architecture for communication to each of the external systems like Billing, CRM, etc., in OSS/BSS system has made the architecture very loosely coupled, with greater flexibility. Any change in the external systems would be absorbed at the Integration Layer without affecting the rest of the ecosystem. The use of a Business Process Management (BPM) tool makes the management and maintenance of the business processes easy, with better performance in terms of lead time, quality, and cost. Since the Architecture is based on standards, it will lower the cost of deploying and managing OSS/BSS applications over their lifecycles.

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Using LINQ Distinct: With an Example on ASP.NET MVC SelectListItem

- by Joe Mayo

One of the things that might be surprising in the LINQ Distinct standard query operator is that it doesn’t automatically work properly on custom classes. There are reasons for this, which I’ll explain shortly. The example I’ll use in this post focuses on pulling a unique list of names to load into a drop-down list. I’ll explain the sample application, show you typical first shot at Distinct, explain why it won’t work as you expect, and then demonstrate a solution to make Distinct work with any custom class. The technologies I’m using are LINQ to Twitter, LINQ to Objects, Telerik Extensions for ASP.NET MVC, ASP.NET MVC 2, and Visual Studio 2010. The function of the example program is to show a list of people that I follow. In Twitter API vernacular, these people are called “Friends”; though I’ve never met most of them in real life. This is part of the ubiquitous language of social networking, and Twitter in particular, so you’ll see my objects named accordingly. Where Distinct comes into play is because I want to have a drop-down list with the names of the friends appearing in the list. Some friends are quite verbose, which means I can’t just extract names from each tweet and populate the drop-down; otherwise, I would end up with many duplicate names. Therefore, Distinct is the appropriate operator to eliminate the extra entries from my friends who tend to be enthusiastic tweeters. The sample doesn’t do anything with the drop-down list and I leave that up to imagination for what it’s practical purpose could be; perhaps a filter for the list if I only want to see a certain person’s tweets or maybe a quick list that I plan to combine with a TextBox and Button to reply to a friend. When the program runs, you’ll need to authenticate with Twitter, because I’m using OAuth (DotNetOpenAuth), for authentication, and then you’ll see the drop-down list of names above the grid with the most recent tweets from friends. Here’s what the application looks like when it runs: As you can see, there is a drop-down list above the grid. The drop-down list is where most of the focus of this article will be. There is some description of the code before we talk about the Distinct operator, but we’ll get there soon. This is an ASP.NET MVC2 application, written with VS 2010. Here’s the View that produces this screen: <%@ Page Language="C#" MasterPageFile="~/Views/Shared/Site.Master" Inherits="System.Web.Mvc.ViewPage<TwitterFriendsViewModel>" %> <%@ Import Namespace="DistinctSelectList.Models" %> <asp:Content ID="Content1" ContentPlaceHolderID="TitleContent" runat="server"> Home Page </asp:Content><asp:Content ID="Content2" ContentPlaceHolderID="MainContent" runat="server"> <fieldset> <legend>Twitter Friends</legend> <div> <%= Html.DropDownListFor( twendVM => twendVM.FriendNames, Model.FriendNames, "<All Friends>") %> </div> <div> <% Html.Telerik().Grid<TweetViewModel>(Model.Tweets) .Name("TwitterFriendsGrid") .Columns(cols => { cols.Template(col => { %> <img src="<%= col.ImageUrl %>" alt="<%= col.ScreenName %>" /> <% }); cols.Bound(col => col.ScreenName); cols.Bound(col => col.Tweet); }) .Render(); %> </div> </fieldset> </asp:Content> As shown above, the Grid is from Telerik’s Extensions for ASP.NET MVC. The first column is a template that renders the user’s Avatar from a URL provided by the Twitter query. Both the Grid and DropDownListFor display properties that are collections from a TwitterFriendsViewModel class, shown below: using System.Collections.Generic; using System.Web.Mvc; namespace DistinctSelectList.Models { /// /// For finding friend info on screen /// public class TwitterFriendsViewModel { /// /// Display names of friends in drop-down list /// public List FriendNames { get; set; } /// /// Display tweets in grid /// public List Tweets { get; set; } } } I created the TwitterFreindsViewModel. The two Lists are what the View consumes to populate the DropDownListFor and Grid. Notice that FriendNames is a List of SelectListItem, which is an MVC class. Another custom class I created is the TweetViewModel (the type of the Tweets List), shown below: namespace DistinctSelectList.Models { /// /// Info on friend tweets /// public class TweetViewModel { /// /// User's avatar /// public string ImageUrl { get; set; } /// /// User's Twitter name /// public string ScreenName { get; set; } /// /// Text containing user's tweet /// public string Tweet { get; set; } } } The initial Twitter query returns much more information than we need for our purposes and this a special class for displaying info in the View. Now you know about the View and how it’s constructed. Let’s look at the controller next. The controller for this demo performs authentication, data retrieval, data manipulation, and view selection. I’ll skip the description of the authentication because it’s a normal part of using OAuth with LINQ to Twitter. Instead, we’ll drill down and focus on the Distinct operator. However, I’ll show you the entire controller, below, so that you can see how it all fits together: using System.Linq; using System.Web.Mvc; using DistinctSelectList.Models; using LinqToTwitter; namespace DistinctSelectList.Controllers { [HandleError] public class HomeController : Controller { private MvcOAuthAuthorization auth; private TwitterContext twitterCtx; /// /// Display a list of friends current tweets /// /// public ActionResult Index() { auth = new MvcOAuthAuthorization(InMemoryTokenManager.Instance, InMemoryTokenManager.AccessToken); string accessToken = auth.CompleteAuthorize(); if (accessToken != null) { InMemoryTokenManager.AccessToken = accessToken; } if (auth.CachedCredentialsAvailable) { auth.SignOn(); } else { return auth.BeginAuthorize(); } twitterCtx = new TwitterContext(auth); var friendTweets = (from tweet in twitterCtx.Status where tweet.Type == StatusType.Friends select new TweetViewModel { ImageUrl = tweet.User.ProfileImageUrl, ScreenName = tweet.User.Identifier.ScreenName, Tweet = tweet.Text }) .ToList(); var friendNames = (from tweet in friendTweets select new SelectListItem { Text = tweet.ScreenName, Value = tweet.ScreenName }) .Distinct() .ToList(); var twendsVM = new TwitterFriendsViewModel { Tweets = friendTweets, FriendNames = friendNames }; return View(twendsVM); } public ActionResult About() { return View(); } } } The important part of the listing above are the LINQ to Twitter queries for friendTweets and friendNames. Both of these results are used in the subsequent population of the twendsVM instance that is passed to the view. Let’s dissect these two statements for clarification and focus on what is happening with Distinct. The query for friendTweets gets a list of the 20 most recent tweets (as specified by the Twitter API for friend queries) and performs a projection into the custom TweetViewModel class, repeated below for your convenience: var friendTweets = (from tweet in twitterCtx.Status where tweet.Type == StatusType.Friends select new TweetViewModel { ImageUrl = tweet.User.ProfileImageUrl, ScreenName = tweet.User.Identifier.ScreenName, Tweet = tweet.Text }) .ToList(); The LINQ to Twitter query above simplifies what we need to work with in the View and the reduces the amount of information we have to look at in subsequent queries. Given the friendTweets above, the next query performs another projection into an MVC SelectListItem, which is required for binding to the DropDownList. This brings us to the focus of this blog post, writing a correct query that uses the Distinct operator. The query below uses LINQ to Objects, querying the friendTweets collection to get friendNames: var friendNames = (from tweet in friendTweets select new SelectListItem { Text = tweet.ScreenName, Value = tweet.ScreenName }) .Distinct() .ToList(); The above implementation of Distinct seems normal, but it is deceptively incorrect. After running the query above, by executing the application, you’ll notice that the drop-down list contains many duplicates. This will send you back to the code scratching your head, but there’s a reason why this happens. To understand the problem, we must examine how Distinct works in LINQ to Objects. Distinct has two overloads: one without parameters, as shown above, and another that takes a parameter of type IEqualityComparer<T>. In the case above, no parameters, Distinct will call EqualityComparer<T>.Default behind the scenes to make comparisons as it iterates through the list. You don’t have problems with the built-in types, such as string, int, DateTime, etc, because they all implement IEquatable<T>. However, many .NET Framework classes, such as SelectListItem, don’t implement IEquatable<T>. So, what happens is that EqualityComparer<T>.Default results in a call to Object.Equals, which performs reference equality on reference type objects. You don’t have this problem with value types because the default implementation of Object.Equals is bitwise equality. However, most of your projections that use Distinct are on classes, just like the SelectListItem used in this demo application. So, the reason why Distinct didn’t produce the results we wanted was because we used a type that doesn’t define its own equality and Distinct used the default reference equality. This resulted in all objects being included in the results because they are all separate instances in memory with unique references. As you might have guessed, the solution to the problem is to use the second overload of Distinct that accepts an IEqualityComparer<T> instance. If you were projecting into your own custom type, you could make that type implement IEqualityComparer<T>, but SelectListItem belongs to the .NET Framework Class Library. Therefore, the solution is to create a custom type to implement IEqualityComparer<T>, as in the SelectListItemComparer class, shown below: using System.Collections.Generic; using System.Web.Mvc; namespace DistinctSelectList.Models { public class SelectListItemComparer : EqualityComparer { public override bool Equals(SelectListItem x, SelectListItem y) { return x.Value.Equals(y.Value); } public override int GetHashCode(SelectListItem obj) { return obj.Value.GetHashCode(); } } } The SelectListItemComparer class above doesn’t implement IEqualityComparer<SelectListItem>, but rather derives from EqualityComparer<SelectListItem>. Microsoft recommends this approach for consistency with the behavior of generic collection classes. However, if your custom type already derives from a base class, go ahead and implement IEqualityComparer<T>, which will still work. EqualityComparer is an abstract class, that implements IEqualityComparer<T> with Equals and GetHashCode abstract methods. For the purposes of this application, the SelectListItem.Value property is sufficient to determine if two items are equal. Since SelectListItem.Value is type string, the code delegates equality to the string class. The code also delegates the GetHashCode operation to the string class.You might have other criteria in your own object and would need to define what it means for your object to be equal. Now that we have an IEqualityComparer<SelectListItem>, let’s fix the problem. The code below modifies the query where we want distinct values: var friendNames = (from tweet in friendTweets select new SelectListItem { Text = tweet.ScreenName, Value = tweet.ScreenName }) .Distinct(new SelectListItemComparer()) .ToList(); Notice how the code above passes a new instance of SelectListItemComparer as the parameter to the Distinct operator. Now, when you run the application, the drop-down list will behave as you expect, showing only a unique set of names. In addition to Distinct, other LINQ Standard Query Operators have overloads that accept IEqualityComparer<T>’s, You can use the same techniques as shown here, with SelectListItemComparer, with those other operators as well. Now you know how to resolve problems with getting Distinct to work properly and also have a way to fix problems with other operators that require equality comparisons. @JoeMayo

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Making Sense of ASP.NET Paths

- by Rick Strahl

ASP.Net includes quite a plethora of properties to retrieve path information about the current request, control and application. There's a ton of information available about paths on the Request object, some of it appearing to overlap and some of it buried several levels down, and it can be confusing to find just the right path that you are looking for. To keep things straight I thought it a good idea to summarize the path options along with descriptions and example paths. I wrote a post about this a long time ago in 2004 and I find myself frequently going back to that page to quickly figure out which path I’m looking for in processing the current URL. Apparently a lot of people must be doing the same, because the original post is the second most visited even to this date on this blog to the tune of nearly 500 hits per day. So, I decided to update and expand a bit on the original post with a little more information and clarification based on the original comments. Request Object Paths Available Here's a list of the Path related properties on the Request object (and the Page object). Assume a path like http://www.west-wind.com/webstore/admin/paths.aspx for the paths below where webstore is the name of the virtual. .blackborder td { border-bottom: solid 1px silver; border-left: solid 1px silver; } Request Property Description and Value ApplicationPath Returns the web root-relative logical path to the virtual root of this app. /webstore/ PhysicalApplicationPath Returns local file system path of the virtual root for this app. c:\inetpub\wwwroot\webstore PhysicalPath Returns the local file system path to the current script or path. c:\inetpub\wwwroot\webstore\admin\paths.aspx Path FilePath CurrentExecutionFilePath All of these return the full root relative logical path to the script page including path and scriptname. CurrentExcecutionFilePath will return the ‘current’ request path after a Transfer/Execute call while FilePath will always return the original request’s path. /webstore/admin/paths.aspx AppRelativeCurrentExecutionFilePath Returns an ASP.NET root relative virtual path to the script or path for the current request. If in a Transfer/Execute call the transferred Path is returned. ~/admin/paths.aspx PathInfo Returns any extra path following the script name. If no extra path is provided returns the root-relative path (returns text in red below). string.Empty if no PathInfo is available. /webstore/admin/paths.aspx/ExtraPathInfo RawUrl Returns the full root relative URL including querystring and extra path as a string. /webstore/admin/paths.aspx?sku=wwhelp40 Url Returns a fully qualified URL including querystring and extra path. Note this is a Uri instance rather than string. http://www.west-wind.com/webstore/admin/paths.aspx?sku=wwhelp40 UrlReferrer The fully qualified URL of the page that sent the request. This is also a Uri instance and this value is null if the page was directly accessed by typing into the address bar or using an HttpClient based Referrer client Http header. http://www.west-wind.com/webstore/default.aspx?Info Control.TemplateSourceDirectory Returns the logical path to the folder of the page, master or user control on which it is called. This is useful if you need to know the path only to a Page or control from within the control. For non-file controls this returns the Page path. /webstore/admin/ As you can see there’s a ton of information available there for each of the three common path formats: Physical Path is an OS type path that points to a path or file on disk. Logical Path is a Web path that is relative to the Web server’s root. It includes the virtual plus the application relative path. ~/ (Root-relative) Path is an ASP.NET specific path that includes ~/ to indicate the virtual root Web path. ASP.NET can convert virtual paths into either logical paths using Control.ResolveUrl(), or physical paths using Server.MapPath(). Root relative paths are useful for specifying portable URLs that don’t rely on relative directory structures and very useful from within control or component code. You should be able to get any necessary format from ASP.NET from just about any path or script using these mechanisms. ~/ Root Relative Paths and ResolveUrl() and ResolveClientUrl() ASP.NET supports root-relative virtual path syntax in most of its URL properties in Web Forms. So you can easily specify a root relative path in a control rather than a location relative path: <asp:Image runat="server" ID="imgHelp" ImageUrl="~/images/help.gif" /> ASP.NET internally resolves this URL by using ResolveUrl("~/images/help.gif") to arrive at the root-relative URL of /webstore/images/help.gif which uses the Request.ApplicationPath as the basepath to replace the ~. By convention any custom Web controls also should use ResolveUrl() on URL properties to provide the same functionality. In your own code you can use Page.ResolveUrl() or Control.ResolveUrl() to accomplish the same thing: string imgPath = this.ResolveUrl("~/images/help.gif"); imgHelp.ImageUrl = imgPath; Unfortunately ResolveUrl() is limited to WebForm pages, so if you’re in an HttpHandler or Module it’s not available. ASP.NET Mvc also has it’s own more generic version of ResolveUrl in Url.Decode: <script src="<%= Url.Content("~/scripts/new.js") %>" type="text/javascript"></script> which is part of the UrlHelper class. In ASP.NET MVC the above sort of syntax is actually even more crucial than in WebForms due to the fact that views are not referencing specific pages but rather are often path based which can lead to various variations on how a particular view is referenced. In a Module or Handler code Control.ResolveUrl() unfortunately is not available which in retrospect seems like an odd design choice – URL resolution really should happen on a Request basis not as part of the Page framework. Luckily you can also rely on the static VirtualPathUtility class: string path = VirtualPathUtility.ToAbsolute("~/admin/paths.aspx"); VirtualPathUtility also many other quite useful methods for dealing with paths and converting between the various kinds of paths supported. One thing to watch out for is that ToAbsolute() will throw an exception if a query string is provided and doesn’t work on fully qualified URLs. I wrote about this topic with a custom solution that works fully qualified URLs and query strings here (check comments for some interesting discussions too). Similar to ResolveUrl() is ResolveClientUrl() which creates a fully qualified HTTP path that includes the protocol and domain name. It’s rare that this full resolution is needed but can be useful in some scenarios. Mapping Virtual Paths to Physical Paths with Server.MapPath() If you need to map root relative or current folder relative URLs to physical URLs or you can use HttpContext.Current.Server.MapPath(). Inside of a Page you can do the following: string physicalPath = Server.MapPath("~/scripts/ww.jquery.js")); MapPath is pretty flexible and it understands both ASP.NET style virtual paths as well as plain relative paths, so the following also works. string physicalPath = Server.MapPath("scripts/silverlight.js"); as well as dot relative syntax: string physicalPath = Server.MapPath("../scripts/jquery.js"); Once you have the physical path you can perform standard System.IO Path and File operations on the file. Remember with physical paths and IO or copy operations you need to make sure you have permissions to access files and folders based on the Web server user account that is active (NETWORK SERVICE, ASPNET typically). Note the Server.MapPath will not map up beyond the virtual root of the application for security reasons. Server and Host Information Between these settings you can get all the information you may need to figure out where you are at and to build new Url if necessary. If you need to build a URL completely from scratch you can get access to information about the server you are accessing: Server Variable Function and Example SERVER_NAME The of the domain or IP Address wwww.west-wind.com or 127.0.0.1 SERVER_PORT The port that the request runs under. 80 SERVER_PORT_SECURE Determines whether https: was used. 0 or 1 APPL_MD_PATH ADSI DirectoryServices path to the virtual root directory. Note that LM typically doesn’t work for ADSI access so you should replace that with LOCALHOST or the machine’s NetBios name. /LM/W3SVC/1/ROOT/webstore Request.Url and Uri Parsing If you still need more control over the current request URL or you need to create new URLs from an existing one, the current Request.Url Uri property offers a lot of control. Using the Uri class and UriBuilder makes it easy to retrieve parts of a URL and create new URLs based on existing URL. The UriBuilder class is the preferred way to create URLs – much preferable over creating URIs via string concatenation. Uri Property Function Scheme The URL scheme or protocol prefix. http or https Port The port if specifically specified. DnsSafeHost The domain name or local host NetBios machine name www.west-wind.com or rasnote LocalPath The full path of the URL including script name and extra PathInfo. /webstore/admin/paths.aspx Query The query string if any ?id=1 The Uri class itself is great for retrieving Uri parts, but most of the properties are read only if you need to modify a URL in order to change it you can use the UriBuilder class to load up an existing URL and modify it to create a new one. Here are a few common operations I’ve needed to do to get specific URLs: Convert the Request URL to an SSL/HTTPS link For example to take the current request URL and converted it to a secure URL can be done like this: UriBuilder build = new UriBuilder(Request.Url); build.Scheme = "https"; build.Port = -1; // don't inject port Uri newUri = build.Uri; string newUrl = build.ToString(); Retrieve the fully qualified URL without a QueryString AFAIK, there’s no native routine to retrieve the current request URL without the query string. It’s easy to do with UriBuilder however: UriBuilder builder = newUriBuilder(Request.Url); builder.Query = ""; stringlogicalPathWithoutQuery = builder.ToString(); What else? I took a look through the old post’s comments and addressed as many of the questions and comments that came up in there. With a few small and silly exceptions this update post handles most of these. But I’m sure there are a more things that go in here. What else would be useful to put onto this post so it serves as a nice all in one place to go for path references? If you think of something leave a comment and I’ll try to update the post with it in the future.© Rick Strahl, West Wind Technologies, 2005-2010Posted in ASP.NET

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Java Logger API

- by Koppar

This is a more like a tip rather than technical write up and serves as a quick intro for newbies. The logger API helps to diagnose application level or JDK level issues at runtime. There are 7 levels which decide the detailing in logging (SEVERE, WARNING, INFO, CONFIG, FINE, FINER, FINEST). Its best to start with highest level and as we narrow down, use more detailed logging for a specific area. SEVERE is the highest and FINEST is the lowest. This may not make sense until we understand some jargon. The Logger class provides the ability to stream messages to an output stream in a format that can be controlled by the user. What this translates to is, I can create a logger with this simple invocation and use it add debug messages in my class: import java.util.logging.*; private static final Logger focusLog = Logger.getLogger("java.awt.focus.KeyboardFocusManager"); if (focusLog.isLoggable(Level.FINEST)) { focusLog.log(Level.FINEST, "Calling peer setCurrentFocusOwner}); LogManager acts like a book keeper and all the getLogger calls are forwarded to LogManager. The LogManager itself is a singleton class object which gets statically initialized on JVM start up. More on this later. If there is no existing logger with the given name, a new one is created. If there is one (and not yet GC’ed), then the existing Logger object is returned. By default, a root logger is created on JVM start up. All anonymous loggers are made as the children of the root logger. Named loggers have the hierarchy as per their name resolutions. Eg: java.awt.focus is the parent logger for java.awt.focus.KeyboardFocusManager etc. Before logging any message, the logger checks for the log level specified. If null is specified, the log level of the parent logger will be set. However, if the log level is off, no log messages would be written, irrespective of the parent’s log level. All the messages that are posted to the Logger are handled as a LogRecord object.i.e. FocusLog.log would create a new LogRecord object with the log level and message as its data members). The level of logging and thread number are also tracked. LogRecord is passed on to all the registered Handlers. Handler is basically a means to output the messages. The output may be redirected to either a log file or console or a network logging service. The Handler classes use the LogManager properties to set filters and formatters. During initialization or JVM start up, LogManager looks for logging.properties file in jre/lib and sets the properties if the file is provided. An alternate location for properties file can also be specified by setting java.util.logging.config.file system property. This can be set in Java Control Panel ? Java ? Runtime parameters as -Djava.util.logging.config.file = <mylogfile> or passed as a command line parameter java -Djava.util.logging.config.file = C:/Sunita/myLog The redirection of logging depends on what is specified rather registered as a handler with JVM in the properties file. java.util.logging.ConsoleHandler sends the output to system.err and java.util.logging.FileHandler sends the output to file. File name of the log file can also be specified. If you prefer XML format output, in the configuration file, set java.util.logging.FileHandler.formatter = java.util.logging.XMLFormatter and if you prefer simple text, set set java.util.logging.FileHandler.formatter =java.util.logging.SimpleFormatter Below is the default logging Configuration file: ############################################################ # Default Logging Configuration File # You can use a different file by specifying a filename # with the java.util.logging.config.file system property. # For example java -Djava.util.logging.config.file=myfile ############################################################ ############################################################ # Global properties ############################################################ # "handlers" specifies a comma separated list of log Handler # classes. These handlers will be installed during VM startup. # Note that these classes must be on the system classpath. # By default we only configure a ConsoleHandler, which will only # show messages at the INFO and above levels. handlers= java.util.logging.ConsoleHandler # To also add the FileHandler, use the following line instead. #handlers= java.util.logging.FileHandler, java.util.logging.ConsoleHandler # Default global logging level. # This specifies which kinds of events are logged across # all loggers. For any given facility this global level # can be overriden by a facility specific level # Note that the ConsoleHandler also has a separate level # setting to limit messages printed to the console. .level= INFO ############################################################ # Handler specific properties. # Describes specific configuration info for Handlers. ############################################################ # default file output is in user's home directory. java.util.logging.FileHandler.pattern = %h/java%u.log java.util.logging.FileHandler.limit = 50000 java.util.logging.FileHandler.count = 1 java.util.logging.FileHandler.formatter = java.util.logging.XMLFormatter # Limit the message that are printed on the console to INFO and above. java.util.logging.ConsoleHandler.level = INFO java.util.logging.ConsoleHandler.formatter = java.util.logging.SimpleFormatter ############################################################ # Facility specific properties. # Provides extra control for each logger. ############################################################ # For example, set the com.xyz.foo logger to only log SEVERE # messages: com.xyz.foo.level = SEVERE Since I primarily use this method to track focus issues, here is how I get detailed awt focus related logging. Just set the logger name to java.awt.focus.level=FINEST and change the default log level to FINEST. Below is a basic sample program. The sample programs are from http://www2.cs.uic.edu/~sloan/CLASSES/java/ and have been modified to illustrate the logging API. By changing the .level property in the logging.properties file, one can control the output written to the logs. To play around with the example, try changing the levels in the logging.properties file and notice the difference in messages going to the log file. Example --------KeyboardReader.java------------------------------------------------------------------------------------- import java.io.*; import java.util.*; import java.util.logging.*; public class KeyboardReader { private static final Logger mylog = Logger.getLogger("samples.input"); public static void main (String[] args) throws java.io.IOException { String s1; String s2; double num1, num2, product; // set up the buffered reader to read from the keyboard BufferedReader br = new BufferedReader (new InputStreamReader (System.in)); System.out.println ("Enter a line of input"); s1 = br.readLine(); if (mylog.isLoggable(Level.SEVERE)) { mylog.log (Level.SEVERE,"The line entered is " + s1); } if (mylog.isLoggable(Level.INFO)) { mylog.log (Level.INFO,"The line has " + s1.length() + " characters"); } if (mylog.isLoggable(Level.FINE)) { mylog.log (Level.FINE,"Breaking the line into tokens we get:"); } int numTokens = 0; StringTokenizer st = new StringTokenizer (s1); while (st.hasMoreTokens()) { s2 = st.nextToken(); numTokens++; if (mylog.isLoggable(Level.FINEST)) { mylog.log (Level.FINEST, " Token " + numTokens + " is: " + s2); } } } } ----------MyFileReader.java---------------------------------------------------------------------------------------- import java.io.*; import java.util.*; import java.util.logging.*; public class MyFileReader extends KeyboardReader { private static final Logger mylog = Logger.getLogger("samples.input.file"); public static void main (String[] args) throws java.io.IOException { String s1; String s2; // set up the buffered reader to read from the keyboard BufferedReader br = new BufferedReader (new FileReader ("MyFileReader.txt")); s1 = br.readLine(); if (mylog.isLoggable(Level.SEVERE)) { mylog.log (Level.SEVERE,"ATTN The line is " + s1); } if (mylog.isLoggable(Level.INFO)) { mylog.log (Level.INFO, "The line has " + s1.length() + " characters"); } if (mylog.isLoggable(Level.FINE)) { mylog.log (Level.FINE,"Breaking the line into tokens we get:"); } int numTokens = 0; StringTokenizer st = new StringTokenizer (s1); while (st.hasMoreTokens()) { s2 = st.nextToken(); numTokens++; if (mylog.isLoggable(Level.FINEST)) { mylog.log (Level.FINEST,"Breaking the line into tokens we get:"); mylog.log (Level.FINEST," Token " + numTokens + " is: " + s2); } } //end of while } // end of main } // end of class ----------MyFileReader.txt------------------------------------------------------------------------------------------ My first logging example -------logging.properties------------------------------------------------------------------------------------------- handlers= java.util.logging.ConsoleHandler, java.util.logging.FileHandler .level= FINEST java.util.logging.FileHandler.pattern = java%u.log java.util.logging.FileHandler.limit = 50000 java.util.logging.FileHandler.count = 1 java.util.logging.FileHandler.formatter = java.util.logging.SimpleFormatter java.util.logging.ConsoleHandler.level = FINEST java.util.logging.ConsoleHandler.formatter = java.util.logging.SimpleFormatter java.awt.focus.level=ALL ------Output log------------------------------------------------------------------------------------------- May 21, 2012 11:44:55 AM MyFileReader main SEVERE: ATTN The line is My first logging example May 21, 2012 11:44:55 AM MyFileReader main INFO: The line has 24 characters May 21, 2012 11:44:55 AM MyFileReader main FINE: Breaking the line into tokens we get: May 21, 2012 11:44:55 AM MyFileReader main FINEST: Breaking the line into tokens we get: May 21, 2012 11:44:55 AM MyFileReader main FINEST: Token 1 is: My May 21, 2012 11:44:55 AM MyFileReader main FINEST: Breaking the line into tokens we get: May 21, 2012 11:44:55 AM MyFileReader main FINEST: Token 2 is: first May 21, 2012 11:44:55 AM MyFileReader main FINEST: Breaking the line into tokens we get: May 21, 2012 11:44:55 AM MyFileReader main FINEST: Token 3 is: logging May 21, 2012 11:44:55 AM MyFileReader main FINEST: Breaking the line into tokens we get: May 21, 2012 11:44:55 AM MyFileReader main FINEST: Token 4 is: example Invocation command: "C:\Program Files (x86)\Java\jdk1.6.0_29\bin\java.exe" -Djava.util.logging.config.file=logging.properties MyFileReader References Further technical details are available here: http://docs.oracle.com/javase/1.4.2/docs/guide/util/logging/overview.html#1.0 http://docs.oracle.com/javase/1.4.2/docs/api/java/util/logging/package-summary.html http://www2.cs.uic.edu/~sloan/CLASSES/java/

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openGL ES - change the render mode from RENDERMODE_WHEN_DIRTY to RENDERMODE_CONTINUOUSLY on touch

- by Sid

i want to change the rendermode from RENDERMODE_WHEN_DIRTY to RENDERMODE_CONTINUOUSLY when i touch the screen. WHAT i Need : Initially the object should be stationary. after touching the screen, it should move automatically. The motion of my object is a projectile motion ans it is working fine. what i get : Force close and a NULL pointer exception. My code : public class BallThrowGLSurfaceView extends GLSurfaceView{ MyRender _renderObj; Context context; GLSurfaceView glView; public BallThrowGLSurfaceView(Context context) { super(context); // TODO Auto-generated constructor stub _renderObj = new MyRender(context); this.setRenderer(_renderObj); this.setRenderMode(RENDERMODE_WHEN_DIRTY); this.requestFocus(); this.setFocusableInTouchMode(true); glView = new GLSurfaceView(context.getApplicationContext()); } @Override public boolean onTouchEvent(MotionEvent event) { // TODO Auto-generated method stub if (event != null) { if (event.getAction() == MotionEvent.ACTION_DOWN) { if (_renderObj != null) { Log.i("renderObj", _renderObj + "lll"); // Ensure we call switchMode() on the OpenGL thread. // queueEvent() is a method of GLSurfaceView that will do this for us. queueEvent(new Runnable() { public void run() { glView.setRenderMode(RENDERMODE_CONTINUOUSLY); } }); return true; } } } return super.onTouchEvent(event); } } PS : i know that i am making some silly mistakes in this, but cannot figure out what it really is.

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WPF ListView as a DataGrid – Part 2

- by psheriff

In my last blog post I showed you how to create GridViewColumn objects on the fly from the meta-data in a DataTable. By doing this you can create columns for a ListView at runtime instead of having to pre-define each ListView for each different DataTable. Well, many of us use collections of our classes and it would be nice to be able to do the same thing for our collection classes as well. This blog post will show you one approach for using collection classes as the source of the data for your ListView. Figure 1: A List of Data using a ListView Load Property NamesYou could use reflection to gather the property names in your class, however there are two things wrong with this approach. First, reflection is too slow, and second you may not want to display all your properties from your class in the ListView. Instead of reflection you could just create your own custom collection class of PropertyHeader objects. Each PropertyHeader object will contain a property name and a header text value at a minimum. You could add a width property if you wanted as well. All you need to do is to create a collection of property header objects where each object represents one column in your ListView. Below is a simple example: PropertyHeaders coll = new PropertyHeaders(); coll.Add(new PropertyHeader("ProductId", "Product ID"));coll.Add(new PropertyHeader("ProductName", "Product Name"));coll.Add(new PropertyHeader("Price", "Price")); Once you have this collection created, you could pass this collection to a method that would create the GridViewColumn objects based on the information in this collection. Below is the full code for the PropertyHeader class. Besides the PropertyName and Header properties, there is a constructor that will allow you to set both properties when the object is created. C#public class PropertyHeader{ public PropertyHeader() { } public PropertyHeader(string propertyName, string headerText) { PropertyName = propertyName; HeaderText = headerText; } public string PropertyName { get; set; } public string HeaderText { get; set; }} VB.NETPublic Class PropertyHeader Public Sub New() End Sub Public Sub New(ByVal propName As String, ByVal header As String) PropertyName = propName HeaderText = header End Sub Private mPropertyName As String Private mHeaderText As String Public Property PropertyName() As String Get Return mPropertyName End Get Set(ByVal value As String) mPropertyName = value End Set End Property Public Property HeaderText() As String Get Return mHeaderText End Get Set(ByVal value As String) mHeaderText = value End Set End PropertyEnd Class You can use a Generic List class to create a collection of PropertyHeader objects as shown in the following code. C#public class PropertyHeaders : List<PropertyHeader>{} VB.NETPublic Class PropertyHeaders Inherits List(Of PropertyHeader)End Class Create Property Header Objects You need to create a method somewhere that will create and return a collection of PropertyHeader objects that will represent the columns you wish to add to your ListView prior to binding your collection class to that ListView. Below is a sample method called GetProperties that builds a list of PropertyHeader objects with properties and headers for a Product object. C#public PropertyHeaders GetProperties(){ PropertyHeaders coll = new PropertyHeaders(); coll.Add(new PropertyHeader("ProductId", "Product ID")); coll.Add(new PropertyHeader("ProductName", "Product Name")); coll.Add(new PropertyHeader("Price", "Price")); return coll;} VB.NETPublic Function GetProperties() As PropertyHeaders Dim coll As New PropertyHeaders() coll.Add(New PropertyHeader("ProductId", "Product ID")) coll.Add(New PropertyHeader("ProductName", "Product Name")) coll.Add(New PropertyHeader("Price", "Price")) Return collEnd Function WPFListViewCommon Class Now that you have a collection of PropertyHeader objects you need a method that will create a GridView and a collection of GridViewColumn objects based on this PropertyHeader collection. Below is a static/Shared method that you might put into a class called WPFListViewCommon. C#public static GridView CreateGridViewColumns( PropertyHeaders properties){ GridView gv; GridViewColumn gvc; // Create the GridView gv = new GridView(); gv.AllowsColumnReorder = true; // Create the GridView Columns foreach (PropertyHeader item in properties) { gvc = new GridViewColumn(); gvc.DisplayMemberBinding = new Binding(item.PropertyName); gvc.Header = item.HeaderText; gvc.Width = Double.NaN; gv.Columns.Add(gvc); } return gv;} VB.NETPublic Shared Function CreateGridViewColumns( _ ByVal properties As PropertyHeaders) As GridView Dim gv As GridView Dim gvc As GridViewColumn ' Create the GridView gv = New GridView() gv.AllowsColumnReorder = True ' Create the GridView Columns For Each item As PropertyHeader In properties gvc = New GridViewColumn() gvc.DisplayMemberBinding = New Binding(item.PropertyName) gvc.Header = item.HeaderText gvc.Width = [Double].NaN gv.Columns.Add(gvc) Next Return gvEnd Function Build the Product Screen To build the window shown in Figure 1, you might write code like the following: C#private void CollectionSample(){ Product prod = new Product(); // Setup the GridView Columns lstData.View = WPFListViewCommon.CreateGridViewColumns( prod.GetProperties()); lstData.DataContext = prod.GetProducts();} VB.NETPrivate Sub CollectionSample() Dim prod As New Product() ' Setup the GridView Columns lstData.View = WPFListViewCommon.CreateGridViewColumns( _ prod.GetProperties()) lstData.DataContext = prod.GetProducts()End Sub The Product class contains a method called GetProperties that returns a PropertyHeaders collection. You pass this collection to the WPFListViewCommon’s CreateGridViewColumns method and it will create a GridView for the ListView. When you then feed the DataContext property of the ListView the Product collection the appropriate columns have already been created and data bound. Summary In this blog you learned how to create a ListView that acts like a DataGrid using a collection class. While it does take a little code to do this, it is an alternative to creating each GridViewColumn in XAML. This gives you a lot of flexibility. You could even read in the property names and header text from an XML file for a truly configurable ListView. NOTE: You can download the complete sample code (in both VB and C#) at my website. http://www.pdsa.com/downloads. Choose Tips & Tricks, then "WPF ListView as a DataGrid – Part 2" from the drop-down. Good Luck with your Coding,Paul Sheriff ** SPECIAL OFFER FOR MY BLOG READERS **Visit http://www.pdsa.com/Event/Blog for a free eBook on "Fundamentals of N-Tier".

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