Dynamically load a JavaScript file

Question

How can you reliably and dynamically load a JavaScript file? This will can be used to implement a module or component that when \'initialized\' the component will dynamical

Answer 1

Here is a simple one with callback and IE support:

function loadScript(url, callback) {

    var script = document.createElement("script")
    script.type = "text/javascript";

    if (script.readyState) { //IE
        script.onreadystatechange = function () {
            if (script.readyState == "loaded" || script.readyState == "complete") {
                script.onreadystatechange = null;
                callback();
            }
        };
    } else { //Others
        script.onload = function () {
            callback();
        };
    }

    script.src = url;
    document.getElementsByTagName("head")[0].appendChild(script);
}

loadScript("https://ajax.googleapis.com/ajax/libs/jquery/1.6.1/jquery.min.js", function () {

     //jQuery loaded
     console.log('jquery loaded');

});