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This is one of the ways in which you can make an asynchronous call (drool) to a JSON feed. JSON is effectively much easier to use than normal XML or XHTML (for AJAX) because as the name says, its already defined in the form of a Javascript object. That's usually a function since most JSON is called via a callback function. I have been looking into JSON as a possible replacement for XML because it reduces lines of code to a bare minimum. And since I am new, something like that helps tons. I'll just briefly explain the working of the dynamic <script> tag as I understand it.

The code for the <script> tag is this:

function dyn_script(url){
     var script=document.createElement('script'); // pretty self explanatory
     script.src=url; // sets the scripts source to the specified url
    document.getElementsByTagName('head')[0].appendChild(script); // appends the tag to the head

The url will include the callback function as well. You can specify variables for parameterized calls to variable urls. Every JSON feed has a mechanism to specify a callback function, usually by appending a &callback= followed by the name of the function. Once this is done, all you need to do is define the function as callback_function_name(json). The json argument is very important, as all other objects are children of this main one. To make the call, just call the above dyn_script(url) with event handlers and it'll become asynchronous. This is the probably the easiest and most effective way to make a AJAJ call. This works because we already have the function definition in the code (not given above). The dynamic script tag makes a function with function({ ... data ...}); which contains all the data. This is technically calling the function (function calls are made by naming the function), which is parsed the data.

I have been using this method to make up a hack, which I plan to release the moment I can clear up the CSS. Until then, hope to see you exploit this well.


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