Smallest JavaScript AJAX library ever!

Thursday, July 27. 2006
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I have built the smallest, easiest and fastest JavaScript AJAX library ever. Inspired by moo.ajax, but without the need for prototype or any other external library - the file has 779 bytes without the comments, but with all formatting in place and some pretty long function and variable names. As presented here it only returns the responseText, but you could easily change that to the full XMLHttpRequest object.

Here is how it works:

• create a callback function
• call microAjax: microAjax("url", callbackfunction)
• That's it, your callback function will be called with the response text as parameter

[edited] I have added a new function - you can now add a post Body as last parameter, but it's optional!

Download microAjax.js

Easy? No?

// microAjax by Stefan Lange-Hegermann
// this code is in the public domain
// you can do with it whatever you want!

function microAjax(url, callbackFunction)
{
    this.bindFunction = function (caller, object) {
        return function() {
            return caller.apply(object, new Array(object));
        }
    }

    this.stateChange = function (object) {
        if (this.request.readyState==4) {
            this.callbackFunction(this.request.responseText);
        }
    }

    this.getRequest = function() {
        if (window.ActiveXObject)
            return new ActiveXObject('Microsoft.XMLHTTP');
        else if (window.XMLHttpRequest)
            return new XMLHttpRequest();
        else
            return false;
    }

    if (arguments[2])
        this.postBody = arguments[2];
    else 
        this.postBody="";

    this.callbackFunction=callbackFunction;
    this.url=url;   
    this.request = this.getRequest();

    if(this.request) {
        this.request.onreadystatechange = this.bindFunction(this.stateChange, this);

        if (this.postBody!="") {
            this.request.open("POST", url, true);
            this.request.setRequestHeader('Content-type', 'application/x-www-form-urlencoded');
            this.request.setRequestHeader('Connection', 'close');
        } else {
            this.request.open("GET", url, true);
        }

        this.request.send(this.postBody);
    }
}