All the Bells-and-Whistles: Anonymous Objects & Prototyping

Demonstration

• Votes for Fred: ?
• Votes for Sally: ?
• Votes for Fido: ?

Watch how the request counter above rises as each request goes out and falls as each response rolls back in. If you click rapidly on one or more vote links, then you will see it more clearly. If the request counter never goes over "1", then your Web browser does not support this more advanced level of JavaScript/ECMAScript.

Explanation

Separation of Concerns

Discuss separating the generic from the page-specific code, to make reusable AJAX prototypes.

Using Prototypes

Discuss creating a new HttpClient object from the prototype of one in HttpClient.js.

Anonymous Objects

Discuss using scope of variable client and depending upon garbage collection to cut down on book-keeping code-clutter.

Code

Viewing Code

• Generic AJAX request object code
• The code that makes the page-specific script work can also be seen in your browser. Just choose View Source from the browser menu, and then examine the <script/> node. There are just two functions to look at: test and clear. Everything specific to this page happens inside those two functions, and all the rest comes from the reusable & generic prototype for creating a new HttpClient object.

Creating Prototypes

Content

HttpClient Prototype Walkthrough

Move this to a different page-chunk?