Microsoft ajax library javascript

Below is an example of the imperative code you can now write to programmatically create a client-side DataView control that displays data from a WCF web service:.

The value of the sys:src attribute gets plugged into the src attribute when the template is loaded. You can then wire-up and specify a itemRendered event handler when you create the DataView control like below:.

This allows you to maintain your template as pure HTML markup, while still displaying the same photo gallery experience at runtime. The Microsoft AJAX Client-side library is now split up across multiple JavaScript files — allowing you to download and use only those script files that you actually need reducing download sizes.

Manually adding all of the script files required to use Ajax controls can be tedious though and error prone. This client script loader helps you automatically load all of the scripts required by a control and execute the scripts in the right order when a page loads. Notice the call to the Sys. When you call Sys. The sys. When all of the scripts required by the components requested are loaded, the Sys.

At runtime the watermark control will cause the textbox to have a watermark that automatically disappears when a user sets the focus on the textbox and starts typing :. The client script loader supports many advanced features including automatic script combining and lazy loading. It can also be smart about downloading either debug or release versions of libraries.

It also allows you to register your own libraries and have them automatically be loaded as well using the Sys. Microsoft ships jQuery as a standard part of the ASP. Specifically, we are now exposing all Microsoft Ajax controls as jQuery plug-ins automatically.

In other words, when you add jQuery to a page, you can use Microsoft Ajax controls just like jQuery plug-ins. For example, the following script demonstrates how you can use jQuery to create a DataView that displays data from a WCF service using a jQuery plugin like code syntax :. Once jQuery is added to the page, Microsoft Ajax Library controls are automatically exposed as jQuery plug-ins.

This means you can create and attach Microsoft Ajax controls using a standard jQuery plugin syntax like above , and fully integrate with the jQuery selector syntax. There are two common ways that people use to reduce the download size of a JavaScript file: compression and minification. However, you can get additional performance benefits by both compressing and minifying your JavaScript files.

In addition to releasing Microsoft Ajax Library Preview 6 , we are today also releasing a new free Microsoft Ajax Minifier utility that can help reduce the size of your JavaScript files considerably.

NET CodePlex website for free. The bottom two files were minified using the Microsoft Ajax Minifier utility. The Microsoft Ajax Minifier supports two levels of minification: normal and hypercrunched. When you use normal minification, the Microsoft Ajax Minifier removes all unnecessary whitespace, comments, curly braces, and semi-colons. When you enable hypercrunching, the Microsoft Ajax Minifier becomes more aggressive in reducing the size of a JavaScript file, and it minifies local variable names and removes unreachable code.

Notice that all unnecessary whitespace has been removed. Notice also that the function parameters firstValue and secondValue have been renamed to b and a. The Microsoft Ajax Minifier download includes the following components:. After you install the Microsoft Ajax Minifier, you can use the Microsoft Ajax Minifier command-line tool to minify a JavaScript file from a command-prompt. Adding the Microsoft Ajax Minifier MSBuild task to your Visual Studio project file allows you to automatically minify all of the JavaScript files in your project whenever you perform a build, and enables you to perform minification in an automated way.

The new simplified imperative syntax should appeal to JavaScript developers. The client script loader makes it much easier to create client controls and optimize the download of files. And, the jQuery integration enables developers using jQuery to take advantage of the client controls, templating, and data access features of the Microsoft Ajax Library without changing their programming style.

Finally, the new Microsoft Ajax Minifier enables you to significantly improve the performance of your Ajax applications by reducing the size of your JavaScript files. You can use the minifier from a command prompt or you can use the minifier when building a project in Visual Studio.

NET Framework classes. NET also includes the ScriptManager control to manage these script libraries and any custom script in your application. Add object-oriented capabilities to your JavaScript code to increase code reuse, flexibility, and maintainability. Use extensions to the JavaScript base types to cut down development time for common scripting tasks. Use debugging extensions and a trace feature for faster and more informative debugging than with traditional JavaScript debugging techniques.

The Microsoft AJAX Library adds a type system and extensions to JavaScript objects to provide frequently used object-oriented features that resemble features in the.

NET Framework. NET applications in a structured way that improves maintainability, makes it easier to add features, and makes it easier to layer functionality. Together, these classes enable you to use an object-oriented programming model for writing client script.

The Type class adds object-oriented features such as namespaces, classes, and inheritance to JavaScript programming. Any JavaScript object that is registered by using the Type class automatically has access to this functionality. The following example shows how to use the Type class to create and register a namespace and a class in a JavaScript file:. Classes can have four kinds of members: fields, properties, methods, and events.

Fields are composed of primitive types and are accessed directly, as in the following example:. Properties can represent any primitive or reference type. You access property values with get and set accessor methods. The following example demonstrates how to add a Person class to the Demo namespace using the Type.

When the page is rendered, the appropriate script references to AJAX client-script libraries are generated automatically. The following example shows a page with a ScriptManager control. The following example shows how to register the namespace, create the class, and then register the class. Most object-oriented programming languages include the concept of access modifiers, which allow you to specify under what contexts a class or member is available, such as to outside programs, internal classes within the same namespace, or only within a specific code block.

There are no access modifiers in JavaScript. You set the default timeout through the defaultTimeout property and you can change the default executor type using the defaultExecutorType property, a string.

By default, the executor is an instance of the Sys. XMLHttpExecutor class and is instantiated just before firing the request. The Sys. As you can see, the executor is a separate module and the manager uses it only through a known interface made of the executeRequest method and the invokingRequest and completedRequest events. The public properties of the object are url, httpVerb, headers, body, timeout, userContext, and executor.

Timeout and executor, if not set, default to the values defined in the Web request manager. The completed event and the invoke method complete the programming interface of the WebRequest object. To trigger a request, you call the invoke method. As you can see, only one request at a time is supported and it is passed on to the request manager for execution:.

The request manager checks to see whether there is an explicit demand for an executor in the packet. If not, it uses the default executor. Next, the request manager fires the invokingRequest method. If the event is not canceled by the user code, the final step takes place: the executor physically sets up the connection and sends the packet.

The executor derives from a base class named WebRequestExecutor, which defines the expected programming interface. This class internally creates an instance of the XMLHttpRequest browser object and uses it to carry the request. A different executor can be specified for each Web request, as it is a property of the Sys. WebRequest object.

The point is, what other techniques and alternatives exist to justify the creation of a custom executor? You should notice that, when using XMLHttpRequest, you're limited to the so-called same-origin-policy that most browsers implement. In practice, it means that browsers do not allow scripted calls to URLs located outside the domain of the current page. WebRequestExecutor and implements all of its abstract members. As for parsing the response into a usable memory object, you might want to define a request-specific parser component that provides a custom behavior under a common programming interface.

Scriptable services need some JavaScript wrapper code in order to be invoked. A script-based proxy class can therefore be generated that provides a public programming interface that is nearly identical to that of the original service—be it a classic ASP.

The proxy class is linked to the page via a script tag that is bound to a specific URL:. The name of the proxy object is the same as the fully qualified name of the service class.

The object also has the same set of methods. Methods, though, have an extended signature that encompasses additional parameters in addition to the standard set of input arguments. In particular, each method adds two callback functions to allow user code the ability to handle a successful or failed call, plus an optional object that represents the context of the call.

The proxy object derives from the Sys. Figure 6 shows a fragment of a service proxy class. For performance reasons, a proxy class is a singleton that executes each of its methods asynchronously in a callback model. Here's a sample fragment:.

A timeout is automatically set and controlled through an internal timer. Furthermore, the proxy registers a handler for the completed event of the Web request.

When the event fires, the system-provided code checks the response. If all went well, the proxy invokes the user-defined success callback. Otherwise, it invokes the failure callback and passes it information about the error that occurred, as in this code snippet:. If the execution of the service method results in an unhandled exception, the message that is associated with the exception, its stacktrace, and its type are carried back to the client and composed into a WebServiceError JavaScript object that the failure callback can work with.

The key object for partial rendering is PageRequestManager, in the Sys. WebForms namespace. The code that initializes the object is transparently inserted in any client page that includes at least one UpdatePanel control.

NET applications. In that case, you can also use AJAX features to manage your custom script as static. Release mode provides error checking and exception handling that is optimized for performance, with minimized script size. Debug mode provides more robust debugging features, such as type and argument checking.

NET runs the debug versions when the application is in debug mode. This enables you to throw exceptions in debug scripts while minimizing the size of release code. The Microsoft AJAX Library, which is a type system and a set of JavaScript extensions that provide namespaces, inheritance, interfaces, enumerations, reflection, and additional features. Partial-page rendering, which updates regions of the page by using an asynchronous postback. For more information, see Partial-Page Rendering Overview.

The ASP. NET 2. It provides additional support for localized. NET can serve localized client scripts and resources automatically for specific languages and regions. Localizing Resources for Component Libraries Overview. NET Web services. The required script references are automatically added to the page, and they in turn automatically generate the Web service proxy classes that you use from client script to call the Web service.

You can also access ASP. To do so, in the page you can manually include references to the Microsoft AJAX Library, to script files, and to the Web service itself.

At run time, ASP. NET generates the proxy classes that you can use to call the services. Application services in ASP. NET forms authentication, roles, and user profiles.

For information and examples, see.