notice the:
(script_filename.indexOf(“?”)?”&”:”?”)

simpler:
if(script_filename.indexOf(“?”))
script_filename +=”&”
else
script_filename +=”?”

a trick lernt from yahoo UI javascript
when appending p-arameters to a url

function include_rpc(script_filename) {

script_filename += (script_filename.indexOf(“?”)?”&”:”?”) + Math.random(0, 1000) + ‘=’ + Math.random(0, 1000);
var html_doc = document.getElementsByTagName(‘head’).item(0);
var js = document.createElement(‘script’);
js.setAttribute(‘language’, ‘javascript’);
js.setAttribute(‘type’, ‘text/javascript’);
js.setAttribute(‘src’, script_filename);
html_doc.appendChild(js);
return false;

}

After calling all the necessary includes, the user calls “waitToLoadFiles(postLoadFunc)” which will periodically check to see if the list of loaded files matches the list of included files. Once the list matches, “postLoadFunc” is executed.

This script is tested in FF1.5.0.8 and works great!! Fails to work in IE5.1, though, and I can’t understand why. It seems to load some files, but then it stops. I’m thinking it has something to do with the include_once function being called again within included files. If anyone can figure it out, let me know!

velocityidp at gmail dot com

var js;
var html_doc = document.getElementsByTagName('head')[0];
var loaded_files = new Array();

function include_js(js_file) {
       js = document.createElement('script');
       js.setAttribute('type', 'text/javascript');
       js.setAttribute('src', js_file);
       js.file = js_file;
       html_doc.appendChild(js);

       js.onreadystatechange = function () {
               if(this.readyState == 'complete')
                       loaded_files[loaded_files.length] = this.file;
       }

       js.onload = function () {
         loaded_files[loaded_files.length] = this.file;
       }
       return false;
}

var css;
function include_css(css_file) {
       css = document.createElement('link');
       css.setAttribute('rel', 'stylesheet');
       css.setAttribute('type', 'text/css');
       css.setAttribute('href', css_file);
       css.file = css_file;
       html_doc.appendChild(css);

       // alert state change
       css.onreadystatechange = function () {
               if (this.readyState == 'complete')
                       loaded_files[loaded_files.length] = this.file;
       }
       css.onload = function () {
               loaded_files[loaded_files.length] = this.file;
       }

       return false;
}

var included_files = new Array();
function include_once(file, type) {
       if (!in_array(file, included_files)) {
       included_files[included_files.length] = file;

       switch(type){
               case 'js':
                       include_js(file);
                       break;
               case 'css':
                       include_css(file);
               default:
                       include_js(file);
                       break;
               }
       }
}

function in_array(needle, haystack) {
       for (var i = 0; i < haystack.length; i++) {
               if (haystack[i] == needle) {
                       return true;
               }
       }
       return false;
}

var granularity = 1000; //ms
function waitToLoadFiles(postLoadFunc){
       if(areAllFilesLoaded())
               setTimeout(postLoadFunc+"()", 1);
       else{
               alert("Not loaded
"+loaded_files.length+"/"+included_files.length+"\n\n"+loaded_files.toString
());
               setTimeout("waitToLoadFiles('"+postLoadFunc+"')",
granularity);
       }
}

function areAllFilesLoaded(){
       if(included_files.length == loaded_files.length)
               return true;
       else
               return false;
}

Depending upon the make up of the external file you are calling you *might* not need to alter it at all. As long as there is a variable/etc being set towards the end of the file you can check for it.
Same as when you use Object detection to test for browser support
if(document.getElementById) { doDomStuff(); }

I also had a thought after having another look at your code, I know if you set an images src attribute as a js file certain browsers will download and execute it like any other external js file (I cant quite remember which at the moment)
So it might be possible to use the Image object’s onload event?

If I can escape my better half’s calls to help around the flat tonight I might get a chance to test this but am thinking something along the lines of….

function loadExternal(url) {
var loader = new Image();
loader.onLoad = externalLoaded;
loader.src = url;
}

function externalLoaded() {
// do stuff
}