/** scriptLoader {singleton} * Provides a means to asynchronously load javascript files. The primary * method, 'load', also accepts a second function argument that will * defer execution until page load. This ensures that all expected scripts * and elements are present and accounted for before script execution begins. */ NNLM.ScriptLoader = function(){ var googleAPIKeys = { "dev_nnlm_gov": 'ABQIAAAAJknBlaenKCe5l6Nj8UBD-BTUHTvS5PfItlKOWHmTZxhWMejmWxSq9w5T04Wu14swiXYZ-MkZiTfaJw', "nnlm_gov": 'ABQIAAAAJknBlaenKCe5l6Nj8UBD-BSuPkKs8fuY3jYx6VEyXVqoolvyFRTMAC6tqsKrWN3LknxxYst7CJU_gQ', "staff_nnlm_gov": 'ABQIAAAAJknBlaenKCe5l6Nj8UBD-BQJNgKKB9VP-O8ygSBP1qlR0E9ZVRTIFMM6Ab0Q3x5WxhiItblmy7T6pw', "dev_staff_nnlm_gov": 'ABQIAAAAJknBlaenKCe5l6Nj8UBD-BQADrzkbHCkz6e8dA6DBSwFcY6w7hSk20KWepxz4ckxmZwNDCWGewmZUg', "emergency_nnlm_gov": 'ABQIAAAAJknBlaenKCe5l6Nj8UBD-BSwQv2I8ihwK-I3Nevt6E0wdDnqxxRGJg0pwHPrQajBDB5BbLqtd1d4rA' }; var activeGoogleAPIKey = googleAPIKeys[ document.URL.replace(/^https?:\/\/([a-z.]+)\/.*/,"$1").replace(/\./g, '_')]; var scripts = { "general": "/scripts/general.js", "mail": "/scripts/mail.js", "roundedcorners": "/scripts/rounded_corners_lite.inc.js", "wordpress": "/scripts/general_wordpress.js", "validator": "http://ajax.microsoft.com/ajax/jquery.validate/1.6/jquery.validate.min.js", "general_adv": "/scripts/GenericFunctions.js", "rgbcolor": "/scripts/rgbcolor.js", "wz_tooltip": "/scripts/wz_tooltip.js", "jquery": "http://ajax.googleapis.com/ajax/libs/jquery/1.4.2/jquery.min.js", "yuieditor": "/scripts/yuieditor.js", "urchin": "http://www.google-analytics.com/urchin.js", "addthis": "/scripts/addthis.js", "debugging" : '/scripts/debugging.js', 'prototype': 'http://ajax.googleapis.com/ajax/libs/prototype/1.6.0.2/prototype.js', 'linkedlist': '/scripts/linkedList.js', 'scriptaculous': 'http://ajax.googleapis.com/ajax/libs/scriptaculous/1.8.1/scriptaculous.js', 'mootools': 'http://ajax.googleapis.com/ajax/libs/mootools/1.11/mootools-yui-compressed.js', 'dojo': 'http://ajax.googleapis.com/ajax/libs/dojo/1.1.1/dojo/dojo.xd.js', 'extcore': '/scripts/ext/ext-core.js', 'extall': '/scripts/ext/ext-all.js', 'googleloader': 'http://www.google.com/jsapi?key='+activeGoogleAPIKey, 'googlefeeds': 'http://www.google.com/uds/solutions/dynamicfeed/gfdynamicfeedcontrol.js', 'feedmaker': '/scripts/feedMaker.js' }; var included = {}; var callbacks = {}; /** loader * nested innner class that serves as a handler for either a single * script or an array of scripts, and a callback function to be * executed when the scripts and the document are loaded. */ var Loader = function(){ var toBeLoaded = 0; var id = false; /** _loadscript * a recursive function that loads all scripts before executing a * final function. The recursive nature is to accomodate for accepting * either a string or an array as an argument, thus loading one or many * prerequisite scripts before executing a dependent javascript * function or functions. * This function has a design guarantee that all scripts it is * created to fetch are not yet available. This guarantee is * satisfied by the parent class. * * @param mixed {mixed} the string or array of strings representing * the src parameter for a javascript file dependency. This string * may be a literal reference, or one of the named references in the * hash "scripts" within this class. * @returns {void} * */ var _loadscript = function(mixed){ if (typeof mixed == 'object' && typeof mixed.splice !== undefined && typeof mixed.splice === 'function'){ //array for (var s in mixed){ if (mixed.hasOwnProperty(s)){ _loadscript(mixed[s]); } } return; } //guarantee that this point, we are dealing with a //string. mixed = mixed.toString(); dump('\nDownloading script ' + mixed); //do a hash lookup if it's a named script (not a literal js source). var src = mixed.match(/.*js$/) ? mixed : scripts[mixed]; //bind a new callback closure to each specific script name. var mycallback = function(name, _startTime){ return function(){ toBeLoaded--; dump('\nScript ' + name + ' loaded. toBeloaded: ' + toBeLoaded); if (toBeLoaded <= 0){ dump('\nScriptLoader: All scripts are finished loading.'); NNLM.bindLoadFn(callbacks[id]); } }; }(mixed, new Date().getTime()); var newscript = document.createElement("script"); newscript.type="text/javascript"; //one callback binding for IE... newscript.onreadystatechange = function() { if (this.readyState == 'loaded' || this.readyState == 'complete') { mycallback(); } }; //one for everyone else. newscript.onload = function(){ mycallback(); }; newscript.src = src; //begin download document.getElementsByTagName("head")[0].appendChild(newscript); }; var result = { /** load * helper function designed to invoke the recursive * callback function. * @param arr {array} a list of string arguments denoting * either site relative script source paths, or predefined * names of scripts. See _loadscript parameter mixed for more info. * @returns {null} */ load: function (arr, _id){ id = _id; toBeLoaded += arr.length; _loadscript(arr); //prevent use of the same loader more than once. this.load = undefined; } }; return result; }; /** * _loaded * checks whether a script has been previously loaded by a * separate invocation of the scriptloader. Stores the script * passed as having been loaded. * @param str {string} the url for the script to be loaded * @returns {boolean} true if the script was previously loaded, * false otherwise. */ var _loaded = function(str){ if (included[str] === undefined){ included[str] = true; return false; } return true; }; /** * doLoad * creates a loader object to load a script. * @param mixed {mixed} either a string representing the script * source, or an array of the same * @param id {number} the hash id in the 'callback' hash of the * callback function to execute once * all scripts in param 1 are loaded. * @returns {void} */ var doLoad = function (mixed, id){ var myloader = new Loader(); myloader.load(mixed, id); }; var result = { /** load * loads a named script if defined as one of the supported preloadable * scripts. * * @param mixed {array, string} the shorthand name of the script, * a literal script name, or an array of either of those. * @param _callback {function} a function to be executed once: * 1) all scripts listed as required by the function are loaded. * a) a list of required scripts is usually passed as an array * for the first argument * 2) the window onload() event has fired. * @returns {void} */ load: function (arr, _callback){ /* eliminate already loaded scripts */ var str = '\nNew scriptloader load. Scripts to be loaded:'; _callback = _callback === undefined ? function(){} : _callback; dump(str); var tmp = []; for (var s in arr){ if (arr.hasOwnProperty(s)){ if (!_loaded(arr[s])){ tmp.push(arr[s]); dump("\n* "+arr[s]); } } } arr = tmp; if (arr.length === 0){ dump('\nscript load already complete - callback function ' + 'shall be bound immediately to page load'); NNLM.bindLoadFn(function(){ _callback(); }); return; } else{ var id = new Date().getTime(); while(callbacks[id] !== undefined){ id += 1; } callbacks[id] = _callback; var myloader = new Loader(); myloader.load(arr, id); return; } }, /** loadObj * provides access to the "load" method, with a few more parameters * permissible, along with room for parameter expansion in the future * by making the argument an object. Permissible object keys: * fn: the callback function (if any) * scripts: an array of scripts to be downloaded. May be literal * or preformatted * debug: level of display for debugging messages on the command * line. Values are 0, 1, 2, and 3, with 0 being off, and 3 * being all. * fnname: a name for the passed callback function. This name * is referenced in debug messages. * @param obj {object} a hashkey of arguments. permissible keys * defined above. * @returns [see load]. */ loadObj: function (obj){ }, /** require * alias for load */ require: function (mixed, _callback){ this.load(mixed, _callback); } }; return result; }();