/** * deferedJsLoader - load js after onload * * (c) 2010 Jan Y. Brueckner * * integration is done by: * * // v--- load 1st!! * * * // v------ call loader * * ... * * 'functionname' specifies a name of an function to call after downloading was * triggerd. The function can be contained within one of the js to load. If * more than one script is loaded with a functionname given, the function that * becomes available in the first place is executed first (read on). * * The loader works as follows: after being called on onload event, the loader * triggers download of the scripts specified. Since downloading may occur in * parallel and it may need some time until the sourced functions become ready, * the downloader triggers a background process. This backgroud process watches * wheter functionnames specified become available (every 300ms) and executes * them. The process stops when all functions were executable. The process * stops with an error message after 5 minutes if there are functions remaining * that were not executable. * */ function deferedJsLoader() { this.scripts = []; // scripts to load this.evals = new Array(); // function names to evaluate this.myinterval = null; // pointer to Interval for evaluation /** * register a function to call after loading of the scripts by name * @param {String} func - function name */ this.registerOnLoad = function(func) { var k = this.evals.length; this.evals[k] = func; }; /** * register a script to load defered * @param {String} jscript - path to script * @param {String} func - function name */ this.deferLoadOf = function(jscript, func) { var k = this.scripts.length; this.scripts[k] = jscript; if ( func !== undefined ) { this.registerOnLoad(func); } }; /** * function called in backgroud, tests whether a function is available * and executes it */ this.runEvals = function() { // iterate on this.evals to eval() registered function names while (this.evals.length > 0) { if (typeof window[this.evals[0].replace(/\(.*$/,"")] != 'function') { // abort break; } else { eval(this.evals.shift() + ";"); } } // clear Interval if (this.evals.length === 0) { window.clearInterval(this.myInterval); } }; /** * function called after a certain time to clean up */ this.clearInterval = function() { if (this.evals.length !== 0) { window.clearInterval(this.myInterval); throw new Error("Could not call function \"" + this.evals[0] + "\" \n page may not work"); } }; /** * bootstrap function */ this.onBoot = function() { // download defered js var headID = document.getElementsByTagName("head")[0]; for (i=0; i