Search Results

Search found 14124 results on 565 pages for 'auto generated'.

Page 175/565 | < Previous Page | 171 172 173 174 175 176 177 178 179 180 181 182  | Next Page >

  • SQL Azure maximum database size rises from 10GB to 50GB in June

    - by Eric Nelson
    At Mix we announced that we will be offering a new 50gb size option in June. If you would like to become an early adopter of this new size option before generally available, send an email to [email protected]  and it will auto-reply with instructions to fill out a survey to nominate your application that requires greater than 10gb of storage. Other announcements included: MARS in April: Execute multiple batches in a single connection Spatial Data in June: Geography and geometry types SQL Azure Labs: SQL Azure Labs provides a place where you can access incubations and early preview bits for products and enhancements to SQL Azure. Currently OData Service for SQL Azure. Related Links: SQL Azure Announcements at MIX http://ukazure.ning.com

    Read the article

  • Byte Size Tips: How to Stop OS X from Changing the Display Brightness Automatically

    - by The Geek
    After getting a new MacBook Air and deciding to try out OS X for a while, I started wondering why the battery would suddenly start dying really fast, but only when I was sitting at the kitchen table. That’s when I noticed the display brightness kept changing on its own… and realized the problem. OS X, just like your phone, and any modern device, tries to figure out the brightness of the room you’re in, and adjust the brightness of the screen. If you are over in Windows, it’s called “Adaptive” brightness, while your phone will just call it “Auto”. While this technology is great in theory, I don’t really need max brightness all the time, and I like to control it manually to make sure I’m getting the best battery life. Open up System Preferences, head to Displays. Then uncheck the Automatically adjust brightness setting.     

    Read the article

  • Taking web sites offline for demonstration

    While working in software development in general, and in web development for a couple of customers it is quite common that it is necessary to provide a test bed where the client is able to get an image, or better said, a feeling for the visions and ideas you are talking about. Usually here at IOS Indian Ocean Software Ltd. we set up a demo web site on one of our staging servers, and provide credentials to the customer to access and review our progress and work ad hoc. This gives us the highest flexibility on both sides, as the test bed is simply online and available 24/7. We can update the structure, the UI and data at any time, and the client is able to view it as it suits best for her/him. Limited or lack of online connectivity But what is going to happen when your client is not capable to be online - no matter for what reasons; here are some more obvious ones: No internet connection (permanently or temporarily) Expensive connection, ie. mobile data package, stay at a hotel, etc. Presentation devices at an exhibition, ie. using tablets or iPads Being abroad for a certain time, and only occasionally online No network coverage, especially on mobile Bad infrastructure, like ie. in Third World countries Providing a catalogue on CD or USB pen drive Anyway, it doesn't matter really. We should be able to provide a solution for the circumstances of our customers. Presentation during an exhibition Recently, we had the following request from a customer: Is it possible to let us have a desktop version of ResortWork.co.uk that we can use for demo purposes at the forthcoming Ski Shows? It would allow us to let stand visitors browse the sites on an iPad to view jobs and training directory course listings. Yes, sure we can do that. Eventually, you might think why don't they simply use 3G enabled iPads for that purpose? As stated above, there might be several reasons for that - low coverage, expensive data packages, etc. Anyway, it is not a question on how to circumvent the request but to deliver a solution to that. Possible solutions... or not? We already did offline websites earlier, and even established complete mirrors of one or two web sites on our systems. There are actually several possibilities to handle this kind of request, and it mainly depends on the system or device where the offline site should be available on. Here, it is clearly expressed that we have to address this on an Apple iPad, well actually, I think that they'd like to use multiple devices during their exhibitions. Following is an overview of possible solutions depending on the technology or device in use, and how it can be done: Replication of source files and database The above mentioned web site is running on ASP.NET, IIS and SQL Server. In case that a laptop or slate runs a Windows OS, the easiest way would be to take a snapshot of the source files and database, and transfer them as local installation to those Windows machines. This approach would be fully operational on the local machine. Saving pages for offline usage This is actually a quite tedious job but still practicable for small web sites Tool based approach to 'harvest' the web site There quite some tools in the wild that could handle this job, namely wget, httrack, web copier, etc. Screenshots bundled as PDF document Not really... ;-) Creating screencast or video Simply navigate through your website and record your desktop session. Actually, we are using this kind of approach to track down difficult problems in order to see and understand exactly what the user was doing to cause an error. Of course, this list isn't complete and I'd love to get more of your ideas in the comments section below the article. Preparations for offline browsing The original website is dynamically and data-driven by ASP.NET, and looks like this: As we have to put the result onto iPads we are going to choose the tool-based approach to 'download' the whole web site for offline usage. Again, depending on the complexity of your web site you might have to check which of the applications produces the best results for you. My usual choice is to use wget but in this case, we run into problems related to the rewriting of hyperlinks. As a consequence of that we opted for using HTTrack. HTTrack comes in different flavours, like console application but also as either GUI (WinHTTrack on Windows) or Web client (WebHTTrack on Linux/Unix/BSD). Here's a brief description taken from the original website about HTTrack: HTTrack is a free (GPL, libre/free software) and easy-to-use offline browser utility. It allows you to download a World Wide Web site from the Internet to a local directory, building recursively all directories, getting HTML, images, and other files from the server to your computer. HTTrack arranges the original site's relative link-structure. Simply open a page of the "mirrored" website in your browser, and you can browse the site from link to link, as if you were viewing it online. And there is an extensive documentation for all options and switches online. General recommendation is to go through the HTTrack Users Guide By Fred Cohen. It covers all the initial steps you need to get up and running. Be aware that it will take quite some time to get all the necessary resources down to your machine. Actually, for our customer we run the tool directly on their web server to avoid unnecessary traffic and bandwidth. After a couple of runs and some additional fine-tuning - explicit inclusion or exclusion of various external linked web sites - we finally had a more or less complete offline version available. A very handsome feature of HTTrack is the error/warning log after completing the download. It contains some detailed information about errors that appeared on the pages and the links within the pages that have been processed. Error: "Bad Request" (400) at link www.resortwork.co.uk/job-details_Ski_hire:tech_or_mgr_or_driver_37854.aspx (from www.resortwork.co.uk/Jobs_A_to_Z.aspx)Error: "Not Found" (404) at link www.247recruit.net/images/applynow.png (from www.247recruit.net/css/global.css)Error: "Not Found" (404) at link www.247recruit.net/activate.html (from www.247recruit.net/247recruit_tefl_jobs_network.html) In our situation, we took the records of HTTP 400/404 errors and passed them to the web development department. Improvements are to be expected soon. ;-) Quality assurance on the full-featured desktop Unfortunately, the generated output of HTTrack was still incomplete but luckily there were only images missing. Being directly on the web server we simply copied the missing images from the original source folder into our offline version. After that, we created an archive and transferred the file securely to our local workspace for further review and checks. From that point on, it wasn't necessary to get any more files from the original web server, and we could focus ourselves completely on the process of browsing and navigating through the offline version to isolate visual differences and functional problems. As said, the original web site runs on ASP.NET Web Forms and uses Postback calls for interaction like search, pagination and partly for navigation. This is the main field of improving the offline experience. Of course, same as for standard web development it is advised to test with various browsers, and strangely we discovered that the offline version looked pretty good on Firefox, Chrome and Safari, but not in Internet Explorer. A quick look at the HTML source shed some light on this, and there are conditional CSS inclusions based on the user agent. HTTrack is not acting as Internet Explorer and so we didn't have the necessary overrides for this browser. Not problematic after all in our case, but you might have to pay attention to this and get the IE-specific files explicitly. And while having a view at the source code, we also found out that HTTrack actually modifies the generated HTML output. In several occasions we discovered that <div> elements were converted into <table> constructs for no obvious reason; even nested structures. Search 'e'nd destroy - sed (or Notepad++) to the rescue During our intensive root cause analysis for a couple of HTML/CSS problems that needed some extra attention it is very helpful to be familiar with any editor that allows search and replace over multiple files like, ie. sed - stream editor for filtering and transforming text on Linux or my personal favourite Notepad++ on Windows. This allowed us to quickly fix a lot of anchors with onclick attributes and Javascript code that was addressed to ASP.NET files instead of their generated HTML counterparts, like so: grep -lr -e '.aspx' * | xargs sed -e 's/.aspx/.html?/g' The additional question mark after the HTML extension helps to separate the query string from the actual target and solved all our missing hyperlinks very fast. The same can be done in Notepad++ on Windows, too. Just use the 'Replace in files' feature and you are settled. Especially, in combination with Regular Expressions (regex). Landscape of browsers Okay, after several runs of HTML/CSS code analysis, searching and replacing some strings in a pool of more than 4.000 files, we finally had a very good match of an offline browsing experience in Firefox and Chrome on Linux. Next, we transferred that modified set of files to a Windows 8 machine for review on Firefox, Chrome and Internet Explorer 7 to 10, and a Mac mini running Mac OS X 10.7 to check the output on Safari and again on Chrome. Besides IE, for reasons already mentioned above, the results were identical. And last but not least it was about to check web site on tablets. Please continue to read on the following articles: Taking web sites offline for demonstration on Galaxy Tablet Taking web sites offline for demonstration on iPad

    Read the article

  • How do I rebuild a corrupt dpkg status file?

    - by Ramón
    Whenever I type sudo apt-get remove and then press the Tab key for auto-completion I get the following message: grep-status: /var/lib/dpkg/status:15945: expected a colon. I don't see anything especially strange at line 15945 in the status file. It's a dot character in the description field of a mono library package and inserting a colon did not help. Removing the line containing the dot did not work either. Overwriting the file with status-old resulted in the same message. Is there some way to rebuild the status file?

    Read the article

  • How to allow remote connections to Flask?

    - by Ilya Smagin
    Inside the system, running on virtual machine, I can access the running server at 127.0.0.1:5000. Although the 'remote' address of the vm is 192.168.56.101 (ping and ssh work fine), I cannot access the server with 192.168.50.101:5000 neither from the virtual machine nor from the local one. I guess there's something preventing remote connections. Here's /etc/network/interfaces: auto eth1 iface eth1 inet static address 192.168.56.101 netmask 255.255.255.0 ufw is inactive. How do I fix this problem?

    Read the article

  • Configure IPv6 on your Linux system (Ubuntu)

    After the presentation on IPv6 at the first event of the Emtel Knowledge Series and some recent discussion on social media networks with other geeks and Linux interested IT people here in Mauritius, I thought that I should give it a try (finally) and tweak my local network infrastructure. Honestly, I have been to busy with contractual project work and it never really occurred to me to set up IPv6 in my LAN. Well, the following paragraphs are going to shed some light on those aspects of modern computer and network technology. This is the first article in a series on IPv6 configuration: Configure IPv6 on your Linux system DHCPv6: Provide IPv6 information in your local network Enabling DNS for IPv6 infrastructure Accessing your web server via IPv6 Piece of advice: This is based on my findings on the internet while reading other people's helpful articles and going through a couple of man-pages on my local system. Let's embrace IPv6 The basic configuration on Linux is actually very simple as the kernel, operating system, and user-space programs support that protocol natively. If your system is ready to go for IP (aka: IPv4), then you are good to go for anything else. At least, I didn't have to install any additional packages on my system(s). We are going to assign a static IPv6 address to the system. Hence, we have to modify the definition of interfaces and check whether we have an inet6 entry specified. Open your favourite text editor and check the following entries (it should be at least similar to this): $ sudo nano /etc/network/interfaces auto eth0# IPv4 configurationiface eth0 inet static  address 192.168.1.2  network 192.168.1.0  netmask 255.255.255.0  broadcast 192.168.1.255# IPv6 configurationiface eth0 inet6 static  pre-up modprobe ipv6  address 2001:db8:bad:a55::2  netmask 64 Of course, you might have to adjust your interface device (eth0) or you might be interested to have multiple directives for additional devices (eth1, eth2, etc.). The auto instruction takes care that your device is enabled and configured during the booting phase. The use of the pre-up directive depends on your kernel configuration but in most scenarios this might be an optional line. Anyways, it doesn't hurt to have it enabled after all - just to be on the safe side. Next, either restart your network subsystem like so: $ sudo service networking restart Or you might prefer to do it manually with identical parameters, like so: $ sudo ifconfig eth0 inet6 add 2001:db8:bad:a55::2/64 In case that you're logged in remotely into your PC (ie. via ssh), it is highly advised to opt for the second choice and add the device manually. You can check your configuration afterwards with one of the following commands (depends on whether it is installed): $ sudo ifconfig eth0eth0      Link encap:Ethernet  HWaddr 00:21:5a:50:d7:94            inet addr:192.168.160.2  Bcast:192.168.160.255  Mask:255.255.255.0          inet6 addr: fe80::221:5aff:fe50:d794/64 Scope:Link          inet6 addr: 2001:db8:bad:a55::2/64 Scope:Global          UP BROADCAST RUNNING MULTICAST  MTU:1500  Metric:1 $ sudo ip -6 address show eth03: eth0: <BROADCAST,MULTICAST,UP,LOWER_UP> mtu 1500 qlen 1000    inet6 2001:db8:bad:a55::2/64 scope global        valid_lft forever preferred_lft forever    inet6 fe80::221:5aff:fe50:d794/64 scope link        valid_lft forever preferred_lft forever In both cases, it confirms that our network device has been assigned a valid IPv6 address. That's it in general for your setup on one system. But of course, you might be interested to enable more services for IPv6, especially if you're already running a couple of them in your IP network. More details are available on the official Ubuntu Wiki. Continue to configure your network to provide IPv6 address information automatically in your local infrastructure.

    Read the article

  • Package Manager Console For More Than Managing Packages

    - by Steve Michelotti
    Like most developers, I prefer to not have to pick up the mouse if I don’t have to. I use the Executor launcher for almost everything so it’s extremely rare for me to ever click the “Start” button in Windows. I also use shortcuts keys when I can so I don’t have to pick up the mouse. By now most people know that the Package Manager Console that comes with NuGet is PowerShell embedded inside of Visual Studio. It is based on its PowerConsole predecessor which was the first (that I’m aware of) to embed PowerShell inside of Visual Studio and give access to the Visual Studio automation DTE object. It does this through an inherent $dte variable that is automatically available and ready for use. This variable is also available inside of the NuGet Package Manager console. Adding a new class file to a Visual Studio project is one of those mundane tasks that should be easier. First I have to pick up the mouse. Then I have to right-click where I want it file to go and select “Add –> New Item…” or “Add –> Class…”   If you know the Ctrl+Shift+A shortcut, then you can avoid the mouse for adding a new item but you have to manually assign a shortcut for adding a new class. At this point it pops up a dialog just so I can enter the name of the class I want. Since this is one of the most common tasks developers do, I figure there has to be an easier way and a way that avoids picking up the mouse and popping up dialogs. This is where your embedded PowerShell prompt in Visual Studio comes in. The first thing you should do is to assign a keyboard shortcut so that you can get a PowerShell prompt (i.e., the Package Manager console) quickly without ever picking up the mouse. I assign “Ctrl+P, Ctrl+M” because “P + M” stands for “Package Manager” so it is easy to remember:   At this point I can type this command to add a new class: PM> $dte.ItemOperations.AddNewItem("Code\Class", "Foo.cs") which will result in the class being added: At this point I’ve satisfied my original goal of not having to pick up a mouse and not having the “Add New Item” dialog pop up. However, having to remember that $dte method call is not very user-friendly at all. The best thing to do is to make this a re-usable function that always loads when Visual Studio starts up. There is a $profile variable that you can use to figure out where that location is for your machine: PM> $profile C:\Users\steve.michelotti\Documents\WindowsPowerShell\NuGet_profile.ps1 If the NuGet_profile.ps1 file does not already exist, you can just create it yourself and place it in the directory. Now you can put a function inside like this: 1: function addClass($className) 2: { 3: if ($className.EndsWith(".cs") -eq $false) { 4: $className = $className + ".cs" 5: } 6: 7: $dte.ItemOperations.AddNewItem("Code\Class", $className) 8: } Since it’s in the NuGet_profile.ps1 file, this function will automatically always be available for me after starting Visual Studio. Now I can simply do this: PM> addClass Foo At this point, we have a *very* nice developer experience. All I did to add a new class was: “Ctrl-P, Ctrl-M”, then “addClass Foo”. No mouse, no pop up dialogs, no complex commands to remember. In fact, PowerShell gives you auto-completion as well. If I type “addc” followed by [TAB], then intellisense pops up: You can see my custom function appear in intellisense above. Now I can type the next letter “c” and [TAB] to auto-complete the command. And if that’s still too many key strokes for you, then you can create your own PowerShell custom alias for your function like this: PM> Set-Alias addc addClass PM> addc Foo While all this is very useful, I did run into some issues which prompted me to make even further customization. This command will add the new class file to the current active directory. Depending on your context, this may not be what you want. For example, by convention all view model objects go in the “Models” folder in an MVC project. So if the current document is in the Controllers folder, it will add your class to that folder which is not what you want. You want it to always add it to the “Models” folder if you are adding a new model in an MVC project. For this situation, I added a new function called “addModel” which looks like this: 1: function addModel($className) 2: { 3: if ($className.EndsWith(".cs") -eq $false) { 4: $className = $className + ".cs" 5: } 6: 7: $modelsDir = $dte.ActiveSolutionProjects[0].UniqueName.Replace(".csproj", "") + "\Models" 8: $dte.Windows.Item([EnvDTE.Constants]::vsWindowKindSolutionExplorer).Activate() 9: $dte.ActiveWindow.Object.GetItem($modelsDir).Select([EnvDTE.vsUISelectionType]::vsUISelectionTypeSelect) 10: $dte.ItemOperations.AddNewItem("Code\Class", $className) 11: } First I figure out the path to the Models directory on line #7. Then I activate the Solution Explorer window on line #8. Then I make sure the Models directory is selected so that my context is correct when I add the new class and it will be added to the Models directory as desired. These are just a couple of examples for things you can do with the PowerShell prompt that you have available in the Package Manager console. As developers we spend so much time in Visual Studio, why would you not customize it so that you can work in whatever way you want to work?! The next time you’re not happy about the way Visual Studio makes you do a particular task – automate it! The sky is the limit.

    Read the article

  • C# Adds Optional and Named Arguments

    Earlier this month Microsoft released Visual Studio 2010, the .NET Framework 4.0 (which includes ASP.NET 4.0), and new versions of their core programming languages: C# 4.0 and Visual Basic 10. In designing the latest versions of C# and VB, Microsoft has worked to bring the two languages into closer parity. Certain features available in C# were missing in VB, and vice-a-versa. Last week I wrote about <a href="http://www.4guysfromrolla.com/articles/042110-1.aspx">Visual Basic 2010's language enhancements</a>, which include implicit line continuation, auto-implemented properties, and collection initializers - three useful features that were available in previous versions of C#. Similarly, C# 4.0 introduces new features to the C# programming language that were

    Read the article

  • What is a quick way to indent a block of text with spaces for use within a web browser?

    - by ændrük
    I occasionally have the need to indent a block of text with spaces for use within a web browser, for example, when formatting a code block on this site or in a post on Launchpad. So far I've just done it by hand by copying four spaces to the clipboard and then mashing keys really fast: ?, Home, Ctrl+V (repeat) What is a quicker way to accomplish this, e.g. copying and pasting to another program? a Firefox or Chrome browser extension? a command to directly modify the clipboard contents? an auto-typing program?

    Read the article

  • How to keep "dot files" under version control?

    - by andrewsomething
    Etckeeper is a great tool for keeping track of changes to your configuration files in /etc A few key things about it really stand out. It can be used with a wide variety of VCSs: git, mercurial, darcs, or bzr. It also does auto commits daily and whenever you install, remove or upgrade package. It also keeps track of file permissions and user/group ownership metadata. I would also like to keep my "dot files" in my home directory under version control as well, preferably bazaar. Does anyone know if a tool like etckeeper exists for this purpose? Worst case, I imagine that a simple cron job running bzr add && bzr ci once or twice a day along with adding ~/Documents, ~/Music, ect to the .bzrignore Anyone already doing something similar with a script? While I'd prefer bazaar, other options might be interesting.

    Read the article

  • Windows Azure ASP.NET MVC 2 Role with Silverlight

    - by GeekAgilistMercenary
    I was working through some scenarios recently with Azure and Silverlight.  I immediately decided a quick walk through for setting up a Silverlight Application running in an ASP.NET MVC 2 Application would be a cool project. This walk through I have Visual Studio 2010, Silverlight 4, and the Azure SDK all installed.  If you need to download any of those go get em? now. Launch Visual Studio 2010 and start a new project.  Click on the section for cloud templates as shown below. After you name the project, the dialog for what type of Windows Azure Cloud Service Role will display.  I selected ASP.NET MVC 2 Web Role, which adds the MvcWebRole1 Project to the Cloud Service Solution. Since I selected the ASP.NET MVC 2 Project type, it immediately prompts for a unit test project.  Because I just want to get everything running first, I will probably be unit testing the Silverlight and just using the MVC Project as a host for the Silverlight for now, and because I would prefer to just add the unit test project later, I am going to select no here. Once you've created the ASP.NET MVC 2 project to host the Silverlight, then create another new project.  Select the Silverlight section under the Installed Templates in the Add New Project dialog.  Then select Silverlight Application. The next dialog that comes up will inquire about using the existing ASP.NET MVC Application I just created, which I do want it to use that so I leave it checked.  The options section however I do not want to check RIA Web Services, do not want a test page added to the project, and I want Silverlight debugging enabled so I leave that checked.  Once those options are appropriately set, just click on OK and the Silverlight Project will be added to the overall solution. The next steps now are to get the Silverlight object appropriately embedded in the web page.  First open up the Site.Master file in the ASP.NET MVC 2 Project located under the Veiws/Shared/ location.  After you open the file review the content of the <header></header> section.  In that section add another <contentplaceholder></contentplaceholder> tag as shown in the code snippet below. <head runat="server"> <title> <asp:ContentPlaceHolder ID="TitleContent" runat="server" /> </title> <link href="../../Content/Site.css" rel="stylesheet" type="text/css" /> <asp:ContentPlaceHolder ID="HeaderContent" runat="server" /> </head> I usually put it toward the bottom of the header section.  It just seems the <title></title> should be on the top of the section and I like to keep it that way. Now open up the Index.aspx page under the ASP.NET MVC 2 Project located in the Views/Home/ directory.  When you open up that file add a <asp:Content><asp:Content> tag as shown in the next snippet. <asp:Content ID="Content1" ContentPlaceHolderID="TitleContent" runat="server"> Home Page </asp:Content>   <asp:Content ID=headerContent ContentPlaceHolderID=HeaderContent runat=server>   </asp:Content>   <asp:Content ID="Content2" ContentPlaceHolderID="MainContent" runat="server"> <h2><%= Html.Encode(ViewData["Message"]) %></h2> <p> To learn more about ASP.NET MVC visit <a href="http://asp.net/mvc" title="ASP.NET MVC Website">http://asp.net/mvc</a>. </p> </asp:Content> In that center tag, I am now going to add what is needed to appropriately embed the Silverlight object into the page.  The first thing I needed is a reference to the Silverlight.js file. <script type="text/javascript" src="Silverlight.js"></script> After that comes a bit of nitty gritty Javascript.  I create another tag (and for those in the know, this is exactly like the generated code that is dumped into the *.html page generated with any Silverlight Project if you select to "add a test page that references the application".  The complete Javascript is below. function onSilverlightError(sender, args) { var appSource = ""; if (sender != null && sender != 0) { appSource = sender.getHost().Source; }   var errorType = args.ErrorType; var iErrorCode = args.ErrorCode;   if (errorType == "ImageError" || errorType == "MediaError") { return; }   var errMsg = "Unhandled Error in Silverlight Application " + appSource + "\n";   errMsg += "Code: " + iErrorCode + " \n"; errMsg += "Category: " + errorType + " \n"; errMsg += "Message: " + args.ErrorMessage + " \n";   if (errorType == "ParserError") { errMsg += "File: " + args.xamlFile + " \n"; errMsg += "Line: " + args.lineNumber + " \n"; errMsg += "Position: " + args.charPosition + " \n"; } else if (errorType == "RuntimeError") { if (args.lineNumber != 0) { errMsg += "Line: " + args.lineNumber + " \n"; errMsg += "Position: " + args.charPosition + " \n"; } errMsg += "MethodName: " + args.methodName + " \n"; }   throw new Error(errMsg); } I literally, since it seems to work fine, just use what is populated in the automatically generated page.  After getting the appropriate Javascript into place I put the actual Silverlight Object Embed code into the HTML itself.  Just so I know the positioning and for final verification when running the application I insert the embed code just below the Index.aspx page message.  As shown below. <asp:Content ID="Content2" ContentPlaceHolderID="MainContent" runat="server"> <h2> <%= Html.Encode(ViewData["Message"]) %></h2> <p> To learn more about ASP.NET MVC visit <a href="http://asp.net/mvc" title="ASP.NET MVC Website"> http://asp.net/mvc</a>. </p> <div id="silverlightControlHost"> <object data="data:application/x-silverlight-2," type="application/x-silverlight-2" width="100%" height="100%"> <param name="source" value="ClientBin/CloudySilverlight.xap" /> <param name="onError" value="onSilverlightError" /> <param name="background" value="white" /> <param name="minRuntimeVersion" value="4.0.50401.0" /> <param name="autoUpgrade" value="true" /> <a href="http://go.microsoft.com/fwlink/?LinkID=149156&v=4.0.50401.0" style="text-decoration: none"> <img src="http://go.microsoft.com/fwlink/?LinkId=161376" alt="Get Microsoft Silverlight" style="border-style: none" /> </a> </object> <iframe id="_sl_historyFrame" style="visibility: hidden; height: 0px; width: 0px; border: 0px"></iframe> </div> </asp:Content> I then open up the Silverlight Project MainPage.xaml.  Just to make it visibly obvious that the Silverlight Application is running in the page, I added a button as shown below. <UserControl x:Class="CloudySilverlight.MainPage" xmlns="http://schemas.microsoft.com/winfx/2006/xaml/presentation" xmlns:x="http://schemas.microsoft.com/winfx/2006/xaml" xmlns:d="http://schemas.microsoft.com/expression/blend/2008" xmlns:mc="http://schemas.openxmlformats.org/markup-compatibility/2006" mc:Ignorable="d" d:DesignHeight="300" d:DesignWidth="400">   <Grid x:Name="LayoutRoot" Background="White"> <Button Content="Button" Height="23" HorizontalAlignment="Left" Margin="48,40,0,0" Name="button1" VerticalAlignment="Top" Width="75" Click="button1_Click" /> </Grid> </UserControl> Just for kicks, I added a message box that would popup, just to show executing functionality also. private void button1_Click(object sender, RoutedEventArgs e) { MessageBox.Show("It runs in the cloud!"); } I then executed the ASP.NET MVC 2 and could see the Silverlight Application in page.  With a quick click of the button, I got a message box.  Success! Now the next step is getting the ASP.NET MVC 2 Project and Silverlight published to the cloud.  As of Visual Studio 2010, Silverlight 4, and the latest Azure SDK, this is actually a ridiculously easy process. Navigate to the Azure Cloud Services web site. Once that is open go back in Visual Studio and right click on the cloud project and select publish. This will publish two files into a directory.  Copy that directory so you can easily paste it into the Azure Cloud Services web site.  You'll have to click on the application role in the cloud (I will have another blog entry soon about where, how, and best practices in the cloud). In the text boxes shown, select the application package file and the configuration file and place them in the appropriate text boxes.  This is the part were it comes in handy to have copied the directory path of the file location.  That way when you click on browser you can just paste that in, then hit enter.  The two files will be listed and you can select the appropriate file. Once that is done, name the service deployment.  Then click on publish.  After a minute or so you will see the following screen. Now click on run.  Once the MvcWebRole1 goes green (the little light symbol to the left of the status) click on the Web Site URL.  Be patient during this process too, it could take a minute or two.  The Silverlight application should again come up just like you ran it on your local machine. Once staging is up and running, click on the circular icon with two arrows to move staging to production.  Once you are done make sure the green light is again go for the production deploy, then click on the Web Site URL to verify the site is working.  At this point I had a successful development, staging, and production deployment. Thanks for reading, hope this was helpful.  I have more Windows Azure and other cloud related material coming, so stay tuned. Original Entry

    Read the article

  • Implications of Java 6 End of Public Updates for EBS Users

    - by Steven Chan (Oracle Development)
    The Support Roadmap for Oracle Java is published here: Oracle Java SE Support Roadmap The latest updates to that page (as of Sept. 19, 2012) state (emphasis added): Java SE 6 End of Public Updates Notice After February 2013, Oracle will no longer post updates of Java SE 6 to its public download sites. Existing Java SE 6 downloads already posted as of February 2013 will remain accessible in the Java Archive on Oracle Technology Network. Developers and end-users are encouraged to update to more recent Java SE versions that remain available for public download. For enterprise customers, who need continued access to critical bug fixes and security fixes as well as general maintenance for Java SE 6 or older versions, long term support is available through Oracle Java SE Support . What does this mean for Oracle E-Business Suite users? EBS users fall under the category of "enterprise users" above.  Java is an integral part of the Oracle E-Business Suite technology stack, so EBS users will continue to receive Java SE 6 updates after February 2013. In other words, nothing will change for EBS users after February 2013.  EBS users will continue to receive critical bug fixes and security fixes as well as general maintenance for Java SE 6. These Java SE 6 updates will be made available to EBS users for the Extended Support periods documented in the Oracle Lifetime Support policy document for Oracle Applications (PDF): EBS 11i Extended Support ends November 2013 EBS 12.0 Extended Support ends January 2015 EBS 12.1 Extended Support ends December 2018 Will EBS users be forced to upgrade to JRE 7 for Windows desktop clients? No. This upgrade will be highly recommended but currently remains optional. JRE 6 will be available to Windows users to run with EBS for the duration of your respective EBS Extended Support period.  Updates will be delivered via My Oracle Support, where you can continue to receive critical bug fixes and security fixes as well as general maintenance for JRE 6 desktop clients.  The certification of Oracle E-Business Suite with JRE 7 (for desktop clients accessing EBS Forms-based content) is in its final stages.  If you plan to upgrade your EBS desktop clients to JRE 7 when that certification is released, you can get a head-start on that today. Coexistence of JRE 6 and JRE 7 on Windows desktops The upgrade to JRE 7 will be highly recommended for EBS users, but some users may need to run both JRE 6 and 7 on their Windows desktops for reasons unrelated to the E-Business Suite. Most EBS configurations with IE and Firefox use non-static versioning by default. JRE 7 will be invoked instead of JRE 6 if both are installed on a Windows desktop. For more details, see "Appendix B: Static vs. Non-static Versioning and Set Up Options" in Notes 290801.1 and 393931.1. Applying Updates to JRE 6 and JRE 7 to Windows desktops Auto-update will keep JRE 7 up-to-date for Windows users with JRE 7 installed. Auto-update will only keep JRE 7 up-to-date for Windows users with both JRE 6 and 7 installed.  JRE 6 users are strongly encouraged to apply the latest Critical Patch Updates as soon as possible after each release. The Jave SE CPUs will be available via My Oracle Support.  EBS users can find more information about JRE 6 and 7 updates here: Information Center: Installation & Configuration for Oracle Java SE (Note 1412103.2) The dates for future Java SE CPUs can be found on the Critical Patch Updates, Security Alerts and Third Party Bulletin.  An RSS feed is available on that site for those who would like to be kept up-to-date. What will Mac users need? Oracle will provide updates to JRE 7 for Mac OS X users. EBS users running Macs will need to upgrade to JRE 7 to receive JRE updates. The certification of Oracle E-Business Suite with JRE 7 for Mac-based desktop clients accessing EBS Forms-based content is underway. Mac users waiting for that certification may find this article useful: How to Reenable Apple Java 6 Plug-in for Mac EBS Users Will EBS users be forced to upgrade to JDK 7 for EBS application tier servers? No. This upgrade will be highly recommended but will be optional for EBS application tier servers running on Windows, Linux, and Solaris.  You can choose to remain on JDK 6 for the duration of your respective EBS Extended Support period.  If you remain on JDK 6, you will continue to receive critical bug fixes and security fixes as well as general maintenance for JDK 6. The certification of Oracle E-Business Suite with JDK 7 for EBS application tier servers on Windows, Linux, and Solaris as well as other platforms such as IBM AIX and HP-UX is planned.  Customers running platforms other than Windows, Linux, and Solaris should refer to their Java vendors's sites for more information about their support policies. Related Articles Planning Bulletin for JRE 7: What EBS Customers Can Do Today EBS 11i and 12.1 Support Timeline Changes Frequently Asked Questions about Latest EBS Support Changes Critical Patch Updates During EBS 11i Exception to Sustaining Support Period

    Read the article

  • Prevent nautilus showing partition mounted in bash script

    - by bcbc
    In my bash script I mount partitions, check them, copy files to them, and unmount. When the script mounts the partition, Nautilus pops up with a Window showing the partition and stealing focus. This is something I want to avoid. Note: I know I can change the behaviour of this in System settings, Details, Removable media, Never prompt or start programs on media insertion, but I don't want to change the behaviour e.g. if a USB stick is plugged in, I just want to prevent it in my bash script. Actually this auto display doesn't seem consistent. If I do the exact same command from the terminal, Nautilus doesn't show, and I know there are other mounts in my script that don't show. So what could be causing this? Here's an example of the code: mkdir -p $target/home mount $target/home $homedev Thanks in advance

    Read the article

  • Naming boolean field that is a verb

    - by dnhang
    In Java, by convention getter and setter for boolean fields will be isField() and setField(). This works perfectly fine with field names that are adjectives like active, visible, closed, etc. But how do I name a field that has meaning of a verb, like haveChildren? Add _ing to the verb (havingChildren), maybe? Edit: to clarify, I don't have control of the method names (getter and setter), they are auto-generated by the IDE. So what I need is an appropriate field name so that when the IDE generate a getter for it, it make senses. For example, hasChildren is a perfect field name, but when the IDE generate the getter for the field it would be isHasChildren. How do I solve this?

    Read the article

  • VirtualBox Share permissions

    - by Eduardo Oliveira
    at the moment i'm running ubuntu server 12.04 on top of a virtual box running as service in M$ w7x64, I've configured the shares on fstab with E /media/E vboxsf auto,rw,uid=1000,gid=1000 0 0 the mount is ok drwxrwxrwx 1 knoker knoker 16384 Sep 1 20:02 E but i cant change the permissions inside of /media/E ,chmod runs but doesn't do nothing. on a specific case /media/E/Docs/Downloads i have dr-xr-xr-x 1 knoker knoker 163840 Sep 1 19:30 Downloads and since i cant seem to be able to change from linux i tried it on the windows, and all users listed have full control... Any ideas on what is happening? Best Regards, Knoker

    Read the article

  • Introduction to LinqPad Driver for StreamInsight 2.1

    - by Roman Schindlauer
    We are announcing the availability of the LinqPad driver for StreamInsight 2.1. The purpose of this blog post is to offer a quick introduction into the new features that we added to the StreamInsight LinqPad driver. We’ll show you how to connect to a remote server, how to inspect the entities present of that server, how to compose on top of them and how to manage their lifetime. Installing the driver Info on how to install the driver can be found in an earlier blog post here. Establishing connections As you click on the “Add Connection” link in the left pane you will notice that now it’s possible to build the data context automatically. The new driver appears as an option in the upper list, and if you pick it you will open a connection dialog that lets you connect to a remote StreamInsight server. The connection dialog lets you specify the address of the remote server. You will notice that it’s possible to pick up the binding information from the configuration file of the LinqPad application (which is normally in the same folder as LinqPad.exe and is called LinqPad.exe.config). In order for the context to be generated you need to pick an application from the server. The control is editable hence you can create a new application if you don’t want to make changes to an existing application. If you choose a new application name you will be prompted for confirmation before this gets created. Once you click OK the connection is created and you can start issuing queries against the remote server. If there’s any connectivity error the connection is marked with a red X and you can see the error message informing you what went wrong (i.e., the remote server could not be reached etc.). The context for remote servers Let’s take a look at what happens after we are connected successfully. Every LinqPad query runs inside a context – think of it as a class that wraps all the code that you’re writing. If you’re connecting to a live server the context will contain the following: The application object itself. All entities present in this application (sources, sinks, subjects and processes). The picture below shows a snapshot of the left pane of LinqPad after a successful connection. Every entity on the server has a different icon which will allow users to figure out its purpose. You will also notice that some entities have a string in parentheses following the name. It should be interpreted as such: the first name is the name of the property of the context class and the second name is the name of the entity as it exists on the server. Not all valid entity names are valid identifier names so in cases where we had to make a transformation you see both. Note also that as you hover over the entities you get IntelliSense with their types – more on that later. Remoting is not supported As you play with the entities exposed by the context you will notice that you can’t read and write directly to/from them. If for instance you’re trying to dump the content of an entity you will get an error message telling you that in the current version remoting is not supported. This is because the entity lives on the remote server and dumping its content means reading the events produced by this entity into the local process. ObservableSource.Dump(); Will yield the following error: Reading from a remote 'System.Reactive.Linq.IQbservable`1[System.Int32]' is not supported. Use the 'Microsoft.ComplexEventProcessing.Linq.RemoteProvider.Bind' method to read from the source using a remote observer. This basically tells you that you can call the Bind() method to direct the output of this source to a sink that has to be defined on the remote machine as well. You can’t bring the results to the LinqPad window unless you write code specifically for that. Compose queries You may ask – what's the purpose of all that? After all the same information is present in the EventFlowDebugger, why bother with showing it in LinqPad? First of all, What gets exposed in LinqPad is not what you see in the debugger. In LinqPad we have a property on the context class for every entity that lives on the server. Because LinqPad offers IntelliSense we in fact have much more information about the entity, and more importantly we can compose with that entity very easily. For example, let’s say that this code creates an entity: using (var server = Server.Connect(...)) {     var a = server.CreateApplication("WhiteFish");     var src = a         .DefineObservable<int>(() => Observable.Range(0, 3))         .Deploy("ObservableSource"); If later we want to compose with the source we have to fetch it and then we can bind something to     a.GetObservable<int>("ObservableSource)").Bind(... This means that we had to know a bunch of things about this: that it’s a source, that it’s an observable, it produces a result with payload Int32 and it’s named “ObservableSource”. Only the second and last bits of information are present in the debugger, by the way. As you type in the query window you see that all the entities are present, you get IntelliSense support for them and it’s much easier to make sense of what’s available. Let’s look at a scenario where composition is plausible. With the new programming model it’s possible to create “cold” sources that are parameterized. There was a way to accomplish that even in the previous version by passing parameters to the adapters, but this time it’s much more elegant because the expression declares what parameters are required. Say that we hover the mouse over the ThrottledSource source – we will see that its type is Func<int, int, IQbservable<int>> - this in effect means that we need to pass two int parameters before we can get a source that produces events, and the type for those events is int – in the particular case of my example I had the source produce a range of integers and the two parameters were the start and end of the range. So we see how a developer can create a source that is not running yet. Then someone else (e.g. an administrator) can pass whatever parameters appropriate and run the process. Proxy Types Here’s an interesting scenario – what if someone created a source on a server but they forgot to tell you what type they used. Worse yet, they might have used an anonymous type and even though they can refer to it by name you can’t figure out how to use that type. Let’s walk through an example that shows how you can compose against types you don’t need to have the definition of. This is how we can create a source that returns an anonymous type: Application.DefineObservable(() => Observable.Range(1, 10).Select(i => new { I = i })).Deploy("O1"); Now if we refresh the connection we can see the new source named O1 appear in the list. But what’s more important is that we now have a type to work with. So we can compose a query that refers to the anonymous type. var threshold = new StreamInsightDynamicDriver.TypeProxies.AnonymousType1_0<int>(5); var filter = from i in O1              where i > threshold              select i; filter.Deploy("O2"); You will notice that the anonymous type defined with this statement: new { I = i } can now be manipulated by a client that does not have access to it because the LinqPad driver has generated another type in its stead, named StreamInsightDynamicDriver.TypeProxies.AnonymousType1_0. This type has all the properties and fields of the type defined on the server, except in this case we can instantiate values and use it to compose more queries. It is worth noting that the same thing works for types that are not anonymous – the test is if the LinqPad driver can resolve the type or not. If it’s not possible then a new type will be generated that approximates the type that exists on the server. Control metadata In addition to composing processes on top of the existing entities we can do other useful things. We can delete them – nothing new here as we simply access the entities through the Entities collection of the application class. Here is where having their real name in parentheses comes handy. There’s another way to find out what’s behind a property – dump its expression. The first line in the output tells us what’s the name of the entity used to build this property in the context. Runtime information So let’s create a process to see what happens. We can bind a source to a sink and run the resulting process. If you right click on the connection you can refresh it and see the process present in the list of entities. Then you can drag the process to the query window and see that you can have access to process object in the Processes collection of the application. You can then manipulate the process (delete it, read its diagnostic view etc.). Regards, The StreamInsight Team

    Read the article

  • DI/IoC in Java for a .NET'er used to Castle.Windsor

    - by Ciddan
    Is there a Java DI container that works in a similar way to the most excellent Castle.Windsor container on the .NET side? The Java containers I've had a look at all seem to rely on annotations (Guice) within my services, which I don't dig all that much - I'd like to go POJO all the way if possible. Spring on the other hand can do without the annotations, but it requires a lot of XML. XML configuration != maintainability. One of the really nice things about Castle.Windsor is the wiring you're able to set up in code with Installers, auto wiring based on naming conventions and whatnot. Ideally the container should also support lifecycle management and configuration; i.e. registering components as transient, singleton, pooled etc. Another bonus would be support for interceptors. Any tips would be greatly appreciated.

    Read the article

  • How to ensure apache2 reads htaccess for custom expiry?

    - by tzot
    I have a site with Apache 2.2.22 . I have enabled the mod-expires and mod-headers modules seemingly correctly: $ apachectl -t -D DUMP_MODULES … expires_module (shared) headers_module (shared) … Settings include: ExpiresActive On ExpiresDefault "access plus 10 minutes" ExpiresByType application/xml "access plus 1 minute" Checking the headers of requests, I see that max-age is set correctly both for the generic case and for xml files (which are auto-generated, but mostly static). I would like to have different expiries for xml files in a directory (e.g. /data), so http://site/data/sample.xml expires 24 hours later. I enter the following in data/.htaccess: ExpiresByType application/xml "access plus 24 hours" Header set Cache-control "max-age=86400, public" but it seems that apache ignores this. How can I ensure apache2 uses the .htaccess directives? I can provide further information if requested.

    Read the article

  • file acess slow after deletion of many files

    - by stefan
    I recently accidentally created millions of files in one folder (rougly 5 million) and due to limitations I couldn't process them correctly (maximum argument count exceeded for wc / ls and such stuff). So I deleted them, which took quite a while, but now they're gone. I deleted the files with a regular rm. It weren't any system files. So the files are definitively deleted, but the system is very slow on file stuff now. ls, cat and auto-complete by pressing tab freezes the terminal for several seconds. Is this some sort of fragmentation issue? Is it an issue with the files beeing still somehow present?

    Read the article

  • Wise settings for Git

    - by Marko Apfel
    These settings reflecting my Git-environment. It a result of reading and trying several ideas of input from others. Must-Haves Aliases [alias] ci = commit st = status co = checkout oneline = log --pretty=oneline br = branch la = log --pretty=\"format:%ad %h (%an): %s\" --date=short df = diff dc = diff --cached lg = log -p lol = log --graph --decorate --pretty=oneline --abbrev-commit lola = log --graph --decorate --pretty=oneline --abbrev-commit --all ls = ls-files ign = ls-files -o -i --exclude-standard Colors [color] ui = auto [color "branch"] current = yellow reverse local = yellow remote = green [color "diff"] meta = yellow bold frag = magenta bold old = red bold new = green bold whitespace = red reverse [color "status"] added = green changed = red untracked = cyan Core [core] autocrlf = true excludesfile = c:/Users/<user>/.gitignore editor = 'C:/Program Files (x86)/Notepad++/notepad++.exe' -multiInst -notabbar -nosession –noPlugin Nice to have Merge and Diff [merge] tool = kdiff3 [mergetool "kdiff3"] path = c:/Program Files (x86)/KDiff3/kdiff3.exe [mergetool "p4merge"] path = c:/Program Files (x86)/Perforce Merge/p4merge.exe cmd = p4merge \"$BASE\" \"$LOCAL\" \"$REMOTE\" \"$MERGED\" keepTemporaries = false trustExitCode = false keepBackup = false [diff] guitool = kdiff3 [difftool "kdiff3"] path = c:/Program Files (x86)/KDiff3/kdiff3.exe [difftool "p4merge"] path = C:/Users/<user>/My Applications/Perforce Merge/p4merge.exe cmd = \"p4merge.exe $LOCAL $REMOTE\" .

    Read the article

  • Pre order Nokia Lumia 900 from AT&T for $99.99 and Walmart for $49.99

    - by Gopinath
    Nokia Lumia 900, the flagship Windows Phone OS smartphone from Nokia is available for pre-order from AT&T Stores. With a two year contract, you can grab the phone by paying $99.99 online and they are expected to ship a day or two earlier than their official launch in AT&T stores across US. Walmart in an aggressive move, is selling Nokia Lumia 900 for just $49.99 with a two year contract. So you save $50 more. Earlier in January of this year, Nokia unveiled its plans of Lumia 900 launch exclusively for American market. Nokia Lumia 900 features a 4.3 inch Clear Black display, sporting a resolution of 800 x 480 pixels, 1.4 GHz Snapdragon processor, Windows Phone 7.5 (Mango) OS, 8 megapixel rear camera with f2.2/28mm Carl Zeiss lens and dual LED flash, auto-focus and HD (720p) video recording, 1 megapixel front-facing camera for video calls, 512 MB RAM, 16 GB internal memory, 14.5 GB user memory and more. Pre-order Nokia Lumia 900 from AT&T and Walmart

    Read the article

  • How to import in BIDS more than one SSIS package in one shot!

    - by Luca Zavarella
    Have you ever wanted to add more than one Integration Services existing package (e.g. 20 packages) in a SSIS project? Well, you may suppose that an Open Dialog supports multiple files selection to import more than one file at a time ... BIDS Open Dialog doesn’t allow this, you can just select a single file! Hence the loss of valuable time spent to import the packages one at a time. Few days ago I learned a trick that solves the problem, thanks to this post by Matt Masson. Just copy all the packages to import from Windows Explorer (Ctrl + C): Then just right click on the SSIS Packages folder of the Integration Services project and make a simple Past (CTRL + V): So “auto-magically” you’ll have all those packages imported in your Integration Services project!! What can I say... this feature was well hidden!

    Read the article

  • Check connection and reconnect wifi

    - by Ruud
    I'm building a wireless photoframe. The one thing I haven't been able to figure out is how to get my wifi connection back up using a recommended method. Right now I edited /etc/network/interfaces so wlan0 is started at boot: auto wlan0 iface wlan0 inet dhcp wireless-essid ourssid This method works fine for booting. But I found that if I do not check the connection for a long time (could be a week) it might be down. So I should reconnect. What I do now to verify the connection is working is downloading a file from the server that can't be cached (http://server.ext/ping.php?randomize=123456) If I fail to retrieve the file I assume that the connection is no longer working and I run a shell script like #!/bin/bash ifconfig wlan0 up iwconfig wlan0 essid "ourssid" dhclient wlan0 And the connection comes back. But I can't find anything if this is in any way a good method. Can this be improved upon, or is this already right?

    Read the article

  • Tudta? - Havonta szemináriumokat tartunk Support témában az Oracle irodában

    - by user552636
          Nézzen be az Oracle Hungary irodájába, ahol általában minden hónap elso hétfojén tájékoztatót tartunk az Oracle támogatásról, hogy Ügyfeleink minél jobban ki tudják használni az Oracle Support nyújtotta lehetoségeket. Ha Ön mindennapi munkája során gyakran lép kapcsolatba az Oracle Support-tal, bizonyára hasznosnak találja majd szemináriumainkat, melyeken tájékoztatást adunk az Oracle Support-tal való hatékony együttmuködés módjáról, a támogató eszközökrol, folyamatokról technológiákról. A szemináriumok ingyenesen látogathatók. A szemináriumsorozat aktuális témájáról a My Oracle Support 1475680.1  cikkébol tájékozódhatnak. Legutóbbi szemináriumon az Oracle Konfiguráció Kezelorol, az Auto Service Request (ASR) -rol, valamint a Licencmigrációról beszéltünk. (E témák anyagait hamarosan feltöltöm a blog-hoz.) A következo szemináriumot rendkívüli módon az Oracle Oktatás "Guru Party-jával" együtt tartjuk, az eladások témáját késobb fogom közzé tenni a 1475680.1 cikkben, valamint ezen a blog-on.  

    Read the article

  • Why unhandled exceptions are useful

    - by Simon Cooper
    It’s the bane of most programmers’ lives – an unhandled exception causes your application or webapp to crash, an ugly dialog gets displayed to the user, and they come complaining to you. Then, somehow, you need to figure out what went wrong. Hopefully, you’ve got a log file, or some other way of reporting unhandled exceptions (obligatory employer plug: SmartAssembly reports an application’s unhandled exceptions straight to you, along with the entire state of the stack and variables at that point). If not, you have to try and replicate it yourself, or do some psychic debugging to try and figure out what’s wrong. However, it’s good that the program crashed. Or, more precisely, it is correct behaviour. An unhandled exception in your application means that, somewhere in your code, there is an assumption that you made that is actually invalid. Coding assumptions Let me explain a bit more. Every method, every line of code you write, depends on implicit assumptions that you have made. Take this following simple method, that copies a collection to an array and includes an item if it isn’t in the collection already, using a supplied IEqualityComparer: public static T[] ToArrayWithItem( ICollection<T> coll, T obj, IEqualityComparer<T> comparer) { // check if the object is in collection already // using the supplied comparer foreach (var item in coll) { if (comparer.Equals(item, obj)) { // it's in the collection already // simply copy the collection to an array // and return it T[] array = new T[coll.Count]; coll.CopyTo(array, 0); return array; } } // not in the collection // copy coll to an array, and add obj to it // then return it T[] array = new T[coll.Count+1]; coll.CopyTo(array, 0); array[array.Length-1] = obj; return array; } What’s all the assumptions made by this fairly simple bit of code? coll is never null comparer is never null coll.CopyTo(array, 0) will copy all the items in the collection into the array, in the order defined for the collection, starting at the first item in the array. The enumerator for coll returns all the items in the collection, in the order defined for the collection comparer.Equals returns true if the items are equal (for whatever definition of ‘equal’ the comparer uses), false otherwise comparer.Equals, coll.CopyTo, and the coll enumerator will never throw an exception or hang for any possible input and any possible values of T coll will have less than 4 billion items in it (this is a built-in limit of the CLR) array won’t be more than 2GB, both on 32 and 64-bit systems, for any possible values of T (again, a limit of the CLR) There are no threads that will modify coll while this method is running and, more esoterically: The C# compiler will compile this code to IL according to the C# specification The CLR and JIT compiler will produce machine code to execute the IL on the user’s computer The computer will execute the machine code correctly That’s a lot of assumptions. Now, it could be that all these assumptions are valid for the situations this method is called. But if this does crash out with an exception, or crash later on, then that shows one of the assumptions has been invalidated somehow. An unhandled exception shows that your code is running in a situation which you did not anticipate, and there is something about how your code runs that you do not understand. Debugging the problem is the process of learning more about the new situation and how your code interacts with it. When you understand the problem, the solution is (usually) obvious. The solution may be a one-line fix, the rewrite of a method or class, or a large-scale refactoring of the codebase, but whatever it is, the fix for the crash will incorporate the new information you’ve gained about your own code, along with the modified assumptions. When code is running with an assumption or invariant it depended on broken, then the result is ‘undefined behaviour’. Anything can happen, up to and including formatting the entire disk or making the user’s computer sentient and start doing a good impression of Skynet. You might think that those can’t happen, but at Halting problem levels of generality, as soon as an assumption the code depended on is broken, the program can do anything. That is why it’s important to fail-fast and stop the program as soon as an invariant is broken, to minimise the damage that is done. What does this mean in practice? To start with, document and check your assumptions. As with most things, there is a level of judgement required. How you check and document your assumptions depends on how the code is used (that’s some more assumptions you’ve made), how likely it is a method will be passed invalid arguments or called in an invalid state, how likely it is the assumptions will be broken, how expensive it is to check the assumptions, and how bad things are likely to get if the assumptions are broken. Now, some assumptions you can assume unless proven otherwise. You can safely assume the C# compiler, CLR, and computer all run the method correctly, unless you have evidence of a compiler, CLR or processor bug. You can also assume that interface implementations work the way you expect them to; implementing an interface is more than simply declaring methods with certain signatures in your type. The behaviour of those methods, and how they work, is part of the interface contract as well. For example, for members of a public API, it is very important to document your assumptions and check your state before running the bulk of the method, throwing ArgumentException, ArgumentNullException, InvalidOperationException, or another exception type as appropriate if the input or state is wrong. For internal and private methods, it is less important. If a private method expects collection items in a certain order, then you don’t necessarily need to explicitly check it in code, but you can add comments or documentation specifying what state you expect the collection to be in at a certain point. That way, anyone debugging your code can immediately see what’s wrong if this does ever become an issue. You can also use DEBUG preprocessor blocks and Debug.Assert to document and check your assumptions without incurring a performance hit in release builds. On my coding soapbox… A few pet peeves of mine around assumptions. Firstly, catch-all try blocks: try { ... } catch { } A catch-all hides exceptions generated by broken assumptions, and lets the program carry on in an unknown state. Later, an exception is likely to be generated due to further broken assumptions due to the unknown state, causing difficulties when debugging as the catch-all has hidden the original problem. It’s much better to let the program crash straight away, so you know where the problem is. You should only use a catch-all if you are sure that any exception generated in the try block is safe to ignore. That’s a pretty big ask! Secondly, using as when you should be casting. Doing this: (obj as IFoo).Method(); or this: IFoo foo = obj as IFoo; ... foo.Method(); when you should be doing this: ((IFoo)obj).Method(); or this: IFoo foo = (IFoo)obj; ... foo.Method(); There’s an assumption here that obj will always implement IFoo. If it doesn’t, then by using as instead of a cast you’ve turned an obvious InvalidCastException at the point of the cast that will probably tell you what type obj actually is, into a non-obvious NullReferenceException at some later point that gives you no information at all. If you believe obj is always an IFoo, then say so in code! Let it fail-fast if not, then it’s far easier to figure out what’s wrong. Thirdly, document your assumptions. If an algorithm depends on a non-trivial relationship between several objects or variables, then say so. A single-line comment will do. Don’t leave it up to whoever’s debugging your code after you to figure it out. Conclusion It’s better to crash out and fail-fast when an assumption is broken. If it doesn’t, then there’s likely to be further crashes along the way that hide the original problem. Or, even worse, your program will be running in an undefined state, where anything can happen. Unhandled exceptions aren’t good per-se, but they give you some very useful information about your code that you didn’t know before. And that can only be a good thing.

    Read the article

< Previous Page | 171 172 173 174 175 176 177 178 179 180 181 182  | Next Page >