Autoloader do sintaxe highlitghter

[rplaurindo]

Pessoal, mexendo nas libs do framework Sintaxe Highlighter, eu vi isso, resumidamente.

function loadScript(url)
    {
        var script = document.createElement('script'),
            done = false
           ;
        
        script.src = url;
        script.type = 'text/javascript';

        script.onload = script.onreadystatechange = function()
        {
            if (!done && (!this.readyState || this.readyState == 'loaded' || this.readyState == 'complete'))
            {
                done = true;
                scripts[url] = true;
                checkAll();
                
                // Handle memory leak in IE
                script.onload = script.onreadystatechange = null;
                script.parentNode.removeChild(script);
            }
        };
        
        // sync way of adding script tags to the page
        document.body.appendChild(script);
    };
    
    function checkAll()
    {
        for(var url in scripts)
            if (scripts[url] == false)
                return false;
        
        if (allCalled)
            SyntaxHighlighter.highlight(allParams);
    };

Gostaria de entender melhor este código. Existe também o onreadystatechange sem usar Ajax, bem como o readystate?

Edited August 1, 2011 by Rafael P L