MSDN Magazine - January 2008 - (Page 65)

Call the project AJAXEnabledWebApplicationI18N1 (I18N is an abbreviation for Internationalization because Internationalization starts with an “I,” has 18 more letters, and ends with an “N”). Add a button to the form and an OnClientClick event to call a JavaScript function named displayAlert: ASP.NET AJAX ScriptManager to the page and configure it to generate links to localizable resources. You do this by setting the ScriptManager’s EnableScriptLocalization property to true. In addition, you need to indicate which resources the page can reference by adding a ScriptReference to the ScriptManager. The complete ScriptManager element follows: Now add a JScript file called DisplayFunctions.js, like so: function displayAlert() { window.alert(DisplayFunctionsResources.Greeting); return false; } The displayAlert function uses window.alert to display DisplayFunctionsResources.Greeting. Note that DisplayFunctionsResources.Greeting doesn’t exist yet, but it is the localizable resource, and I refer to it as if it were a strongly typed resource class. I will return to this idea later. Using the Properties Window, set the Build Action for the DisplayFunctions.js file to Embedded Resource. This tells the compiler to embed DisplayFunctions.js as a resource in the resulting AJAXEnabledWebApplicationI18N1.dll assembly. Next we want to make it easy for the user to set the culture used by the Web application, so we add Culture and UICulture attributes to the page header and set them to auto. Of course, these page attributes are added automatically if you use “Tools | Generate Local Resource” as you would normally do when localizing an ASP.NET application, but I want to add them manually in this example because I want it to be clear that the ASP.NET AJAX localization models do not require you to also use the ASP.NET localization model. Now add a Resource file and call it DisplayFunctionsResources.resx. Add a resource entry called Greeting and give it a value of “Hello World”. At this point, you should be able to see what the reference to DisplayFunctionsResources.Greeting in DisplayFunctions.js will be pointing at. Now add a Resource file called DisplayFunctionsResources.fr.resx and a resource entry called Greeting, and give it the value “Bonjour Le Monde”. This resource file uses the standard .NET Framework .resx file-naming convention of including the culture name (here fr for French) before the .resx file extension. You’ll just have to trust me while performing the next step until I explain later how it all works. For now, you need to know that the resources in your Web application (DisplayFunctions.js, DisplayFunctionsResources.resx, and DisplayFunctionsResources.fr.resx) are made available to your page using the WebResource and ScriptResource HTTP handlers. These handlers do not make all resources available automatically; instead, they look for assembly attributes that mark the resources they are allowed to expose. Open the project’s AssemblyInfo.cs file and add these assembly attributes to the file: [assembly: System.Web.UI.WebResource( “AJAXEnabledWebApplicationI18N1.DisplayFunctions.js”, “text/javascript”)] [assembly: System.Web.UI.ScriptResource( “AJAXEnabledWebApplicationI18N1.DisplayFunctions.js”, “AJAXEnabledWebApplicationI18N1.DisplayFunctionsResources”, “DisplayFunctionsResources”)] The ScriptReference includes the name of the JavaScript resource and a reference to the resource’s assembly. Finally, you can run your completed Web application. Click on the button and you will see the English resource (“Hello World”), assuming that your system’s default lanASP.NET 2.0 has an guage is set to English. To excellent localization see the French resources model for Web applications, in Internet Explorer®, open Tools | Internet Options, and the .NET Framework click on the Languages butincludes considerable ton, click on the Add butglobalization support. ton, select French (France), click OK twice, refresh the page, and finally click on the button in your application and the French resource (“Bonjour Le Monde”) will be shown. How It Works So now you have a working localized ASP.NET AJAX application, but it was built without a good understanding of how the framework actually makes it work. In this section, I will connect the dots. It all begins with web.config. Take a look at the HTTP handlers section and you will find a ScriptResource handler: To expose these resources to the page, you need to add the This ScriptResourceHandler is referenced in your page when you add EnableScriptLocalization=“true” to your ScriptManager. If you go ahead and enable script localization in a freshly created, unchanged ASP.NET AJAX-Enabled Web Application, view the source HTML and you will see the lines shown in Figure 1. The WebResource reference will be there regardless of whether you have enabled script localization, but, since all of the handlers use the same parameters, that’s where we’ll start. The key to understanding what ASP.NET AJAX is doing lies in understanding the parameters. In Figure 1, you can see that there are two parameters: d and t. The parameter d represents the data and t is a date/time stamp. The t parameter is simply the DateTime (represented in ticks) of the assembly that contains the resource. A value of 632969072944906146 represents 20th October 2006 02:14:54, which is the date/time stamp for System.Web.dll. The benefit of this parameter is that the result returned by the HTTP january2008 65

Table of Contents Feed for the Digital Edition of MSDN Magazine - January 2008

MSDN Magazine - January 2008 Contents Toolbox CLR Inside Out Data Points Advanced Basics Cutting Edge IIS 7.0 - Enhance Your Apps with the Integrated ASP.NET Pipeline World Ready - Around the World with ASP.NET AJAX Applications WCF Syndication - HTTP Programming with WCF and the .NET Framework 3.5 Wicked Code Foundations Extreme ASP.NET {End Bracket}

MSDN Magazine - January 2008

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