scriptLoader.js

define(function() {

    var ScriptLoader = function(url, ns, onLoadCallback, name) {
        this.url = url; // url of the module
        this.ns = ns; // source obj/ns obj to bind 'define' method
        this.onLoadCallback = onLoadCallback;
        this.name = name; // dependency name
        this.load();
    };

    ScriptLoader.prototype.timer = function timer(times, // number of times to try
                     delay, // delay per try
                     delayMore, // extra delay per try (additional to delay)
                     test, // called each try, timer stops if this returns true
                     failure, // called on failure
                     result // used internally, shouldn't be passed
            ) {
console.log('in timer');
        if (times == -1 || times > 0) {
            setTimeout(function () {
                result = (test()) ? 1 : 0;
                timer((result) ? 0 : (times > 0) ? --times : times, delay + ((delayMore) ? delayMore : 0), delayMore, test, failure, result);
            }, (result || delay < 0) ? 0.1 : delay);
        } else if (typeof failure == 'function') {
            setTimeout(failure, 1);
        }
    };

    ScriptLoader.prototype.addEvent = function (el, eventName, eventFunc) {

        if (typeof el != 'object') {
            return false;
        }

        if (el.addEventListener) {
            el.addEventListener(eventName, eventFunc, false);
            return true;
        }

        if (el.attachEvent) {
            el.attachEvent("on" + eventName, eventFunc);
            return true;
        }

        return false;
    };
    ScriptLoader.prototype.load = function() {

        var that = this;
        var delay;

        var script = document.createElement('script');
        var head = document.head || document.getElementsByTagName('head')[0];
        if (!head) {
            return false;
        }
        Modulerjs.bindDefine(this.ns);
        setTimeout(function () {

            var fail = function () {
                if (!script.__es) {
                    script.__es = true;
                    script.id = 'failed';
                    that.fail.call(script);
                }
            };

            script.onload = function () {
                script.id = 'loaded';
                that.onLoadCallback(that.name);
            };
            if (script.readyState) {
                script.onreadystatechange = function() {
                    if (script.readyState == 'loaded' || script.readyState == 'complete') {
                        script.id = 'loaded';
                        script.onreadystatechange = null;
                    }
                };

            }
            script.type = 'text/javascript';
            // script.async = (typeof args.async == 'boolean') ? args.async : false;
            script.charset = 'utf-8';
            that.__es = false;
            that.addEvent(script, 'error', fail); // when supported
            // when error event is not supported fall back to timer
            that.timer(3, 1000, 0, function () {
                return (script.id == 'loaded');
            }, function () {
                if (script.id != 'loaded') {
                    fail();
                }
            });
            script.src = that.url;
            setTimeout(function () {
                try {
                    head.appendChild(script);
                } catch (e) {
                    fail();
                }
            }, 1);
        }, (typeof delay == 'number') ? delay : 1);

        return true;
    };

    ScriptLoader.prototype.fail = function() {
        throw new Error('script load error url: ' + this.src);
    };

    return ScriptLoader;
});