loader.js

/**
 * User: Semen Kamenetskiy
 * Date: 05.09.13
 */

!function () {

    'use strict';

    /**
     * Global object container
     * @type {*|window|{}}
     */
    var root = window || this || {};

    /**
     * Document object container
     * @type {*|HTMLDocument|{}}
     */
    var doc = root.document || {};

    /**
     * Determines if the DOM is ready
     * @type {boolean}
     * @private
     */
    var __domReady = false;

    /**
     * Contains a list of scripts to load when the DOM is ready
     * @type {Array}
     * @private
     */
    var __domReadyScripts = [];

    /**
     * DOM ready method
     * @param method
     * @private
     */
    function __onDomReady(method) {
        var eventName = 'addEventListener';
        doc[eventName]
            ? doc[eventName]('DOMContentLoaded', method)
            : root.attachEvent('onload', method);
    }

    /**
     * Attached new script to DOM
     * @param {string} src
     * @param {boolean} [async]
     * @private
     */
    function __loadScript(src, async) {
        var script = doc.createElement('script');
        script.setAttribute('type', 'text/javascript');
        script.setAttribute('src', src);
        if (true === async) {
            script.setAttribute('async', 'true');
        }
        doc.getElementsByTagName('head')[0].appendChild(script);
    }

    /**
     * JsLoader constructor
     * @returns {JsLoader}
     * @constructor
     */
    function JsLoader() {
        this.name = 'JsLoader';
        return this;
    }

    /**
     * JsLoader prototype
     * @type {{load: Function}}
     */
    JsLoader.prototype = {

        /**
         * Loads the script when the dom is ready
         * @param src
         * @param async
         * @returns {*}
         */
        'load': function (src, async) {
            if (true === __domReady) {
                __loadScript(src, async || false);
                return this;
            }

            __domReadyScripts.push({
                src: src,
                async: async || false
            });

            return this;
        }

    };

    /**
     * Setting global
     * @type {JsLoader}
     */
    root['JsLoader'] = new JsLoader;

    /**
     * Attaching domReady event
     */
    __onDomReady(function () {
        __domReady = true;
        for (var i in __domReadyScripts) {
            if (!__domReadyScripts.hasOwnProperty(i)) {
                continue;
            }

            __loadScript(
                __domReadyScripts[i].src,
                __domReadyScripts[i].async
            );
        }
    });

}();

loader.min.js

!function(){function f(a,c){var d=b.createElement("script");d.setAttribute("type","text/javascript");d.setAttribute("src",a);!0===c&&d.setAttribute("async","true");b.getElementsByTagName("head")[0].appendChild(d)}function g(){this.name="JsLoader";return this}var e=window||this||{},b=e.document||{},h=!1,c=[];g.prototype={load:function(a,b){if(!0===h)return f(a,b||!1),this;c.push({src:a,async:b||!1});return this}};e.JsLoader=new g;(function(a){b.addEventListener?b.addEventListener("DOMContentLoaded",
a):e.attachEvent("onload",a)})(function(){h=!0;for(var a in c)c.hasOwnProperty(a)&&f(c[a].src,c[a].async)})}();