I had to manage an array of functions (with parameters), and execute them when onload event fires.
I know I could use jQuery's $(window).load(), but we all know that to reduce page loading time, every js script (jquery, jquery plugins, ...) must be inserted at page bottom, just before </body>.
Therefore the only js I'm loading in <head> is this:
var fn_chain = [];
function addFn2Load(fn) {
if(typeof fn != 'function')return;
fn_chain.push(fn);
}
function doLoad() {
for(var i=0,iL=fn_chain.length;i<iL;i++) {
fn_chain[i]();
}
}
if (window.addEventListener) {
window.addEventListener("load", doLoad, false);
} else if (window.attachEvent) {
window.attachEvent("onload", doLoad);
} else if (window.onLoad) {
window.onload = doLoad;
}
Then I can push functions in my array from everywhere in the page, without the need of loading jQuery first. I just write
addFn2Load(function() {
foo(arg1, arg2, argN);
bar(arg1, arg2);
$("#myElementId").myCoolPlugin(); // I can use $ even if jQuery is not loaded yet
});
My solution simply works... Could some javascript guru tell me if I'm doing it right? Is it improvable?
The window.load events fire AFTER the jQuery.ready event. See this other question. So the answer is no, you're not doing this quite right. The only reason you're able to use $ is becuase jQuery did already load.
As #Kevin B mentioned, if you have code that does not require for the document to be ready, you should separate those and run those directly (don't use window.onLoad or jQuery.ready).
<script>
/* Do all your non jQuery stuff here, don't bind to any event handlers. */
</script>
<script src="http://code.jquery.com/jquery-1.11.0.min.js" />
<script>
jQuery(document).ready(function($){
/* do your jQuery stuff here */
});
</script>
<script src="js/my_jq_plugins_minified.js" />
If you want a better way to execute callback functions with arbitrary arguments, I would use:
<script>
function _trigger_callbacks(callbacks) {
var i;
for(i = 0; i < callbacks.length; i++) {
callbacks[i][0].apply(this, callbacks[i][1]);
}
}
// Prepare an array where each entry in this array is an array. For each array:
// - the first entry should be a function
// - the second entry should an array of arguments
fxns = [
[function(a){ alert("Do " + a);}, ["Apple"]],
[function(a, b, c){ alert("Minus = " + (a - b - c));}, [1,2,3]],
];
_trigger_callbacks(fxns);
</script>
For more on the Function.apply method, see this other question.
Doing this with javascript makes little to no sense. The purpose of including your external scripts at the bottom of the page is to allow the page to be generated before downloading the javascript which will result in a faster looking page load.
If you are including scripts in the middle of the page that add function calls to an array that gets executed at the bottom, that defeats the whole purpose of including the scripts at the end because those scripts will have to be downloaded before the rest of the page after said scripts are generated.
If you're pages are dynamically generated with a dynamic header and footer, it would be much easier and more efficient to do this work server-side. If they aren't being generated dynamically, then i don't understand why you are including scripts in the middle in the first place.
I made a little script that makes my JS initialization in Partial Pages a bit easier.
It simply searches for all data-onload attributes, and executes the function defined there on-load.
There is also some other functionality. So is the data-onload called automatically when that specific partial view is loaded through an AJAX call.
Anyway, the syntax looks like this:
<div class="some-partial-html-stuff">
<button>[...]</button>
</div>
<script data-onload="partialInit">
function partialInit()
{
// executes onload and on-ajax-load stuff for this Partial Page
$('.some-partial-html-stuff button').doSomething();
}
function otherFunctions()
{
// [...]
}
</script>
The only thing that I still would love to tackle is that right now I need to have a unique functionName for every partial page (otherwise the names will clash when they are both loaded).
So I have manageProfileInit(), editImageInit() etc.
Now is the OCD-devil in me wondering if there is some way to clean this up even further (without too many negative consequences). I would love to have the situation where I can have a simple clean functon init() in any scriptblocks, and have the same funcionality described above.
Of course in the current situation all the functions will override each other. But does anyone know a nice trick or workaround how this could work?
To summarize, I want to make a script that makes sure this will work on every Partial Page, without any clashes.
<div class="some-partial-html-stuff">
<button>[...]</button>
</div>
<script data-autoinit>
function init()
{
// this method is automatically called if the 'data-autoinit' is defined
// executes onload and on-ajax-load stuff for this Partial Page
$('.some-partial-html-stuff button').doSomething();
}
</script>
When I do stuff like this, I call them features. Tags look like this:
<div data-feature="featureName"></div>
Then we get all of the tags that have the data-feature tag and loop over them, creating an array of features the page is going to use:
var featureObjects = $('[data-feature]');
var features = [];
if ( !featureObjects.length ) return false;
for ( var i = 0, j=featureObjects.length; i<j; i++ ) {
var feature = $(featureObjects[i]).data('features');
if ($.inArray(feature, features) == -1){
if (feature !== ""){
features.push(feature);
}
}
};
Now you'll want to load the JS file asychronously and call it's init function once it's loaded:
for (var i=0, j=features.length; i<j; i++){
var feature = features[i];
$.ajax({
url: "path/to/js/" + feature + ".js",
dataType: "script",
async: false,
success: function () {
App.features[feature].init();
},
error: function () {
throw new Error("Could not load script " + script);
}
});
}
The actual modules look like this and attach themselves to App.features for later use:
App.features.featureName = (function(feature){
// INIT FUNCTION
feature.init = function(){
};
return feature;
}(App.features.featureName || {}));
Just remember to make sure App.features is an array before doing all of this, hopefully somewhere towards the top of your main.js file. I keep other functionality such as helpers and utilities in the app, so I usually kick it off with something like:
var App = {
utilities: {},
features: {},
helpers: {},
constants: {}
};
Now you can just tag DOM objects with a data-feature tag and functionality will be added automatically and as-needed, keeping a nice tie between specific JavaScript and specific DOM, but without the need of having to keep the JS inline next to the actual DOM. It also makes those "blurbs" re-usable should they need to be used elsewhere, which lowers maintenance overhead when working on your application.
I am using jquery dialogs to present forms (fetched via AJAX). On some forms I am using a CKEditor for the textareas. The editor displays fine on the first load.
When the user cancels the dialog, I am removing the contents so that they are loaded fresh on a later request. The issue is, once the dialog is reloaded, the CKEditor claims the editor already exists.
uncaught exception: [CKEDITOR.editor] The instance "textarea_name" already exists.
The API includes a method for destroying existing editors, and I have seen people claiming this is a solution:
if (CKEDITOR.instances['textarea_name']) {
CKEDITOR.instances['textarea_name'].destroy();
}
CKEDITOR.replace('textarea_name');
This is not working for me, as I receive a new error instead:
TypeError: Result of expression 'i.contentWindow' [null] is not an object.
This error seems to occur on the "destroy()" rather than the "replace()". Has anyone experienced this and found a different solution?
Is is possible to 're-render' the existing editor, rather than destroying and replacing it?
UPDATED
Here is another question dealing with the same problem, but he has provided a downloadable test case.
For this to work you need to pass boolean parameter true when destroying instance:
var editor = CKEDITOR.instances[name];
if (editor) { editor.destroy(true); }
CKEDITOR.replace(name);
function loadEditor(id)
{
var instance = CKEDITOR.instances[id];
if(instance)
{
CKEDITOR.remove(instance);
}
CKEDITOR.replace(id);
}
I had this problem too, but I solved it in a much simpler way...
I was using the class "ckeditor" in my jQuery script as the selector for which textareas I wanted use for CKEditor. The default ckeditor JS script also uses this class to identify which textareas to use for CKEditor.
This meant there is a conflict between my jQuery script and the default ckeditor script.
I simply changed the class of the textarea and my jQuery script to 'do_ckeditor'(you could use anything except "ckeditor") and it worked.
This is the simplest (and only) solution that worked for me:
if(CKEDITOR.instances[editorName])
delete CKEDITOR.instances[editorName];
CKEDITOR.replace(editorName);
Deleting this entry in the array prevents this form safety check from destroying your application.
destroy() and remove() did not work for me.
Perhaps this will help you out - I've done something similar using jquery, except I'm loading up an unknown number of ckeditor objects. It took my a while to stumble onto this - it's not clear in the documentation.
function loadEditors() {
var $editors = $("textarea.ckeditor");
if ($editors.length) {
$editors.each(function() {
var editorID = $(this).attr("id");
var instance = CKEDITOR.instances[editorID];
if (instance) { instance.destroy(true); }
CKEDITOR.replace(editorID);
});
}
}
And here is what I run to get the content from the editors:
var $editors = $("textarea.ckeditor");
if ($editors.length) {
$editors.each(function() {
var instance = CKEDITOR.instances[$(this).attr("id")];
if (instance) { $(this).val(instance.getData()); }
});
}
UPDATE: I've changed my answer to use the correct method - which is .destroy(). .remove() is meant to be internal, and was improperly documented at one point.
var e= CKEDITOR.instances['sample'];
e.destroy();
e= null;
I've had similar issue where we were making several instances of CKeditor for the content loaded via ajax.
CKEDITOR.remove()
Kept the DOM in the memory and didn't remove all the bindings.
CKEDITOR.instance[instance_id].destroy()
Gave the error i.contentWindow error whenever I create new instance with new data from ajax. But this was only until I figured out that I was destroying the instance after clearing the DOM.
Use destroy() while the instance & it's DOM is present on the page, then it works perfectly fine.
For ajax requests,
for(k in CKEDITOR.instances){
var instance = CKEDITOR.instances[k];
instance.destroy()
}
CKEDITOR.replaceAll();
this snipped removes all instances from document.
Then creates new instances.
The i.contentWindow is null error seems to occur when calling destroy on an editor instance that was tied to a textarea no longer in the DOM.
CKEDITORY.destroy takes a parameter noUpdate.
The APIdoc states:
If the instance is replacing a DOM element, this parameter indicates whether or not to update the element with the instance contents.
So, to avoid the error, either call destroy before removing the textarea element from the DOM, or call destory(true) to avoid trying to update the non-existent DOM element.
if (CKEDITOR.instances['textarea_name']) {
CKEDITOR.instances['textarea_name'].destroy(true);
}
(using version 3.6.2 with jQuery adapter)
This is what worked for me:
for(name in CKEDITOR.instances)
{
CKEDITOR.instances[name].destroy()
}
CKEDITOR.instances = new Array();
I am using this before my calls to create an instance (ones per page load). Not sure how this affects memory handling and what not. This would only work if you wanted to replace all of the instances on a page.
I've prepared my own solution based on all above codes.
$("textarea.ckeditor")
.each(function () {
var editorId = $(this).attr("id");
try {
var instance = CKEDITOR.instances[editorId];
if (instance) { instance.destroy(true); }
}
catch(e) {}
finally {
CKEDITOR.replace(editorId);
}
});
It works perfectly for me.
Sometimes after AJAX request there is wrong DOM structure.
For instace:
<div id="result">
<div id="result>
//CONTENT
</div>
</div>
This will cause issue as well, and ckEditor will not work. So make sure that you have correct DOM structure.
i had the same problem with instances, i was looking everywhere and finally this implementation works for me:
//set my instance id on a variable
myinstance = CKEDITOR.instances['info'];
//check if my instance already exist
if (myinstance) {
CKEDITOR.remove(info)
}
//call ckeditor again
$('#info').ckeditor({
toolbar: 'Basic',
entities: false,
basicEntities: false
});
You can remove any ckeditor instance by remove method of ckeditor. Instance will be id or name of the textarea.
if (CKEDITOR.instances[instance_name]) {
CKEDITOR.remove(CKEDITOR.instances[instance_name]);
}
Indeed, removing the ".ckeditor" class from your code solves the issue. Most of us followed the jQuery integration example from the ckeditor's documentation:
$('.jquery_ckeditor')
.ckeditor( function() { /* callback code */ }, { skin : 'office2003' } );
and thought "... maybe I can just get rid or the '.jquery_' part".
I've been wasting my time tweaking the callback function (because the {skin:'office2003'} actually worked), while the problem was coming from elsewhere.
I think the documentation should mention that the use of "ckeditor" as a class name is not recommended, because it is a reserved keyword.
Cheers.
I learned that
delete CKEDITOR.instances[editorName];
by itself, actually removed the instance. ALL other methods i have read and seen, including what was found here at stackoverflow from its users, did not work for me.
In my situation, im using an ajax call to pull a copy of the content wrapped around the and 's. The problem happens to be because i am using a jQuery .live event to bind a "Edit this document" link and then applying the ckeditor instance after success of the ajax load. This means, that when i click another link a link with another .live event, i must use the delete CKEDITOR.instances[editorName] as part of my task of clearing the content window (holding the form), then re-fetching content held in the database or other resource.
I hade the same problem with a jQuery Dialog.
Why destroy the instance if you just want to remove previous data ?
function clearEditor(id)
{
var instance = CKEDITOR.instances[id];
if(instance)
{
instance.setData( '' );
}
}
I chose to rename all instances instead of destroy/replace - since sometimes the AJAX loaded instance doesn't really replace the one on the core of the page... keeps more in RAM, but less conflict this way.
if (CKEDITOR && CKEDITOR.instances) {
for (var oldName in CKEDITOR.instances) {
var newName = "ajax"+oldName;
CKEDITOR.instances[newName] = CKEDITOR.instances[oldName];
CKEDITOR.instances[newName].name = newName;
delete CKEDITOR.instances[oldName];
}
}
I am in the situation where I have to controls that spawn dialogs, each of them need to have a ckeditor embedded inside these dialogs. And it just so happens the text areas share the same id. (normally this is very bad practice, but I have 2 jqGrids, one of assigned items and another of unassigned items.) They share almost identical configuration. Thus, I am using common code to configure both.
So, when I load a dialog, for adding rows, or for editing them, from either jqGrid; I must remove all instances of CKEDITOR in all textareas.
$('textarea').each(function()
{
try
{
if(CKEDITOR.instances[$(this)[0].id] != null)
{
CKEDITOR.instances[$(this)[0].id].destroy();
}
}
catch(e)
{
}
});
This will loop over all textareas, and if there is a CKEDITOR instance, then destroy it.
Alternatively if you use pure jQuery:
$('textarea').each(function()
{
try
{
$(this).ckeditorGet().destroy();
}
catch(e)
{
}
});
remove class="ckeditor" , it might have triggered ckeditor initialization
I had the same problem where I was receiving a null reference exception and the word "null" would be displayed in the editor. I tried a handful of solutions, including upgrading the editor to 3.4.1 to no avail.
I ended up having to edit the source. At about line 416 to 426 in _source\plugins\wysiwygarea\plugin.js, there's a snippet like this:
iframe = CKEDITOR.dom.element.createFromHtml( '<iframe' + ... + '></iframe>' );
In FF at least, the iframe isn't completely instantiated by the time it's needed. I surrounded the rest of the function after that line with a setTimeout function:
iframe = CKEDITOR.dom.element.createFromHtml( '<iframe' + ... + '></iframe>' );
setTimeout(function()
{
// Running inside of Firefox chrome the load event doesn't bubble like in a normal page (#5689)
...
}, 1000);
};
// The script that launches the bootstrap logic on 'domReady', so the document
...
The text renders consistently now in the modal dialogs.
To support dynamic (Ajax) loading of forms (without page refreshes between) which contain textareas with the same (same form is called again) or different ID's (previously unloaded form) and convert them to CKEditor elements I did the following (using the JQuery adapter):
After the page has finished every Ajax call that delivers a textarea to be converted, I make a call to the following function:
setupCKeditor()
This looks like this (it assumes your textareas to be converted to RTE's have class="yourCKClass"):
/* Turns textAreas into TinyMCE Rich Text Editors where
* class: tinymce applied to textarea.
*/
function setupCKeditor(){
// define editor configuration
var config = {skin : 'kama'};
// Remove and recreate any existing CKEditor instances
var count = 0;
if (CKEDITOR.instances !== 'undefined') {
for(var i in CKEDITOR.instances) {
var oEditor = CKEDITOR.instances[i];
var editorName = oEditor.name;
// Get the editor data.
var data = $('#'+editorName).val();
// Check if current instance in loop is the same as the textarea on current page
if ($('textarea.yourCKClass').attr('id') == editorName) {
if(CKEDITOR.instances[editorName]) {
// delete and recreate the editor
delete CKEDITOR.instances[editorName];
$('#'+editorName).ckeditor(function() { },config);
count++;
}
}
}
}
// If no editor's exist in the DOM, create any that are needed.
if (count == 0){
$('textarea.yourCKClass').each( function(index) {
var editorName = $(this).attr('id');
$('#'+editorName).ckeditor(function() { $('#'+editorName).val(data); },config);
});
}
}
I should mention that the line:
$('#'+editorName).ckeditor(function() { $('#'+editorName).val(data); },config);
could (and should) be simply:
$('#'+editorName).ckeditor(function() { },config);
however I found that the editor would often show the correct content for a second after loading and them empty the editor of the desired content. So that line with the callback code forces the CKEditor content to be the same as the originating textarea content. Causes a flicker when used. If you can avoid using it, do so..
I had exactly the same problem like jackboberg. I was using dynamic form loading into jquery dialogs then attaching various widgets (datepickers, ckeditors etc...).
And I tried all solutions noted above, none of them worked for me.
For some reason ckeditor only attached the first time I loaded form, the second time I got exactly the same error message jackboberg did.
I've analyzed my code and discovered that if you attach ckeditor in "mid-air" that is while form content is still not placed into dialog, ckeditor won't properly attach its bindings. That is since ckeditor is attached in "mid-air", second time you attach it in "mid-air"... poof ... an error is thrown since the first instance was not properly removed from DOM.
This was my code that ptoduced the error:
var $content = $(r.content); // jQuery can create DOM nodes from html text gotten from <xhr response> - so called "mid-air" DOM creation
$('.rte-field',$content).ckeditor(function(){});
$content.dialog();
This is the fix that worked:
var $content = $(r.content).dialog(); // first create dialog
$('.rte-field',$content).ckeditor(function(){}); // then attach ckeditor widget
I ran into this exact same thing and the problem was that the wordcount plugin was taking too long to initialize. 30+ seconds. The user would click into the view displaying the ckeditor, then cancel, thereby ajax-loading a new page into the dom. The plugin was complaining because the iframe or whatever contentWindow is pointing to was no longer visible by the time it was ready to add itself to the contentWindow. You can verify this by clicking into your view and then waiting for the Word Count to appear in the bottom right of the editor. If you cancel now, you won't have a problem. If you don't wait for it, you'll get the i.contentWindow is null error. To fix it, just scrap the plugin:
if (CKEDITOR.instances['textarea_name'])
{
CKEDITOR.instances['textarea_name'].destroy();
}
CKEDITOR.replace('textarea_name', { removePlugins: "wordcount" } );
If you need a word counter, register for the paste and keyup events on the editor with a function that counts the words.
For those using the jquery "adapter" and having trouble (as I was), as super hackish yet working solution is to do something like this:
// content editor plugin
(function($){
$.fn.contentEditor = function( params ) {
var xParams = $.extend({}, $.fn.contentEditor.defaultParams, params);
return this.each( function() {
var $editor = $(this);
var $params = $.extend({}, xParams, $editor.data());
// if identifier is set, detect type based on identifier in $editor
if( $params.identifier.type ) {
$params.type = $editor.find($params.identifier.type).val();
}
$editor.data('type', $params.type);
// edit functionality
editButton = $('<button>Edit Content</button>').on('click',function(){
// content container
var $cc = $('#' + $editor.data('type'));
// editor window
var $ew = $('<form class="editorWindow" />');
$ew.appendTo('body');
// editor content
$ec = $('<textarea name="editorContent" />').val($cc.html());
$ec.appendTo($ew);
$ec.ckeditor();
//$ec.ckeditorGet().setMode('source');
$ew.dialog({
"autoOpen": true,
"modal": true,
"draggable": false,
"resizable": false,
"width": 850,
"height": 'auto',
"title": "Content Editor",
"buttons": {
'Save': function() {
$cc.html( $ec.val() );
$ec.ckeditorGet().destroy();
$ew.remove();
},
'Cancel / Close': function() {
$ec.ckeditorGet().destroy();
$ew.remove();
}
},
'close': function() {
$ec.ckeditorGet().destroy();
},
'open': function() {
$ew.find('a.cke_button_source').click();
setTimeout(function(){
$ew.find('a.cke_button_source.cke_on').click();
}, 500);
}
});
return false;
});
editButton.appendTo( $editor );
});
}
// set default option values
$.fn.contentEditor.defaultParams = {
'identifier': {
'type': 'input[name="type"]'
}
};
})(jQuery);
$(function(){
$('form.contentEditor').contentEditor();
});
The key point being this part:
'open': function() {
$ew.find('a.cke_button_source').click();
setTimeout(function(){
$ew.find('a.cke_button_source.cke_on').click();
}, 500);
}
This fixes the problem with the editor text not being visible the next time you open the dialog. I realise this is very hackish, but considering that most of these are going to be used for admin tools, I don't think that's as big a concern as it normally would be.. and this works, so hopefully it will save someone some time ;)
This is the fully working code for jquery .load() api and ckeditor, in my case I am loading a page with ckeditor into div with some jquery effects. I hope it will help you.
$(function() {
runEffect = function(fileload,lessonid,act) {
var selectedEffect = 'drop';
var options = {};
$( "#effect" ).effect( selectedEffect, options, 200, callback(fileload,lessonid,act) );
};
function callback(fileload,lessonid,act) {
setTimeout(function() {//load the page in effect div
$( "#effect" ).load(fileload,{lessonid:lessonid,act:act});
$("#effect").show( "drop",
{direction: "right"}, 200 );
$("#effect").ajaxComplete(function(event, XMLHttpRequest, ajaxOptions) {
loadCKeditor(); //call the function after loading page
});
}, 100 );
};
function loadCKeditor()
{//you need to destroy the instance if already exist
if (CKEDITOR.instances['introduction'])
{
CKEDITOR.instances['introduction'].destroy();
}
CKEDITOR.replace('introduction').getSelection().getSelectedText();
}
});
===================== button for call the function ================================
<input type="button" name="button" id="button" onclick="runEffect('lesson.php','','add')" >
Its pretty simple. In my case, I ran the below jquery method that will destroy ckeditor instances during a page load. This did the trick and resolved the issue -
JQuery method -
function resetCkEditorsOnLoad(){
for(var i in CKEDITOR.instances) {
editor = CKEDITOR.instances[i];
editor.destroy();
editor = null;
}
}
$(function() {
$(".form-button").button();
$(".button").button();
resetCkEditorsOnLoad(); // CALLING THE METHOD DURING THE PAGE LOAD
.... blah.. blah.. blah.... // REST OF YOUR BUSINESS LOGIC GOES HERE
});
That's it. I hope it helps you.
Cheers,
Sirish.
This functions works for me in CKEditor version 4.4.5, it does not have any memory leaks
function CKEditor_Render(CkEditor_id) {
var instance = CKEDITOR.instances[CkEditor_id];
if (CKEDITOR.instances.instance) {
CKEDITOR.instances.instance.destroy();
}
CKEDITOR.replace(CkEditor_id);
}
// call this function as below
var id = 'ckeditor'; // Id of your textarea
CKEditor_Render(id);
CKeditor 4.2.1
There is a lot of answers here but for me I needed something more (bit dirty too so if anyone can improve please do). For me MODALs where my issue.
I was rendering the CKEditor in a modal, using Foundation. Ideally I would have destoryed the editor upon closing, however I didn't want to mess with Foundation.
I called delete, I tried remove and another method but this was what I finally settled with.
I was using textarea's to populate not DIVs.
My Solution
//hard code the DIV removal (due to duplication of CKeditors on page however they didn't work)
$("#cke_myckeditorname").remove();
if (CKEDITOR.instances['myckeditorname']) {
delete CKEDITOR.instances['myckeditorname'];
CKEDITOR.replace('myckeditorname', GetCKEditorSettings());
} else {
CKEDITOR.replace('myckeditorname', GetCKEditorSettings());
}
this was my method to return my specific formatting, which you might not want.
function GetCKEditorSettings()
{
return {
linkShowAdvancedTab: false,
linkShowTargetTab: false,
removePlugins: 'elementspath,magicline',
extraAllowedContent: 'hr blockquote div',
fontSize_sizes: 'small/8px;normal/12px;large/16px;larger/24px;huge/36px;',
toolbar: [
['FontSize'],
['Bold', 'Italic', 'Underline', '-', 'NumberedList', 'BulletedList', '-', 'Link', 'Unlink'],
['Smiley']
]
};
}
Try this:
for (name in CKEDITOR.instances)
{
CKEDITOR.instances[name].destroy(true);
}
I'm having some concurrency issues with a webpage I'm building. Basically, I have three script files that I'm using to hold some data:
script1.js:
var myValue = 1;
script2.js:
var myValue = 2;
script3.js:
var myValue = 3;
And I have one page, mypage.html that basically looks like this:
<html>
<script>
function get_number()
{
var script_file = GetQueryStringValue( "run" );
e = document.createElement('script');
e.type='text/javascript';
e.src = script_file + ".js"
head.appendChild( e );
document.write( myValue );
}
</script>
<body onload="get_number()">
<div onclick="get_number()">Click me!</div>
</body>
</html>
The main idea with this page is that you would query it like this:
mypage.html?run=script1
which would tell the get_number() function to dynamically insert script1.js in to mypage.htm. Then, I call get_number() to display the value loaded from the script.
Now, I've stripped down the above to what I think are the relevant parts and I've left out a bunch of stuff, obviously. My actual code loads a large array of values and is more interesting... But, I'm hoping someone can help me out with this regardless.
What I'm finding is that in IE, the number displays correctly.
In Firefox, Chrome and Safari, I get an error that myValue is undefined. However, if I click the Click me div that I created, the number displays correctly. So, I know I'm correctly loading the javascript external file. But, it just isn't loaded in time for my get_number() function to work correctly onload.
Now, I hacked up my file a little so that the get_number function looks like this:
function get_number()
{
var script_file = GetQueryStringValue( "run" );
e = document.createElement('script');
e.type='text/javascript';
e.src = script_file + ".js"
head.appendChild( e );
setTimeout( function() { document.write( myValue ), 10 } );
}
The setTimeout delays enough for the DOM to be updated and the javascript to be loaded in most cases. But, this is a total hack. Firefox tends to load this 'improved' code correctly all the time while Chrome and Safari manage to get the value about 50% of the time.
So, I guess I'm wondering, is there a better way to accomplish what I'm trying to do here? It's very important that the value be driven externally (by the query string), but other than that requirement, I'm very flexible.
This method of dynamically loading script files using DOM methods like head.appendChild is asynchronous, meaning that the page does not wait for it to load before running any further code. If you did not want this asynchronous behaviour, you could load them with regular elements in your HTML, or you could mess around with a 'synchronous' XMLHttpRequest to grab it and eval() to run it.
You probably don't want to do that, though, because being asynchronous makes the entire page load faster, anyway. You will probably just need to add some logic that waits for the dynamically loaded script to have loaded before you go on with the next bit of code. This may, however, involve polling using setInterval() until you notice a variable from the included script has been defined. Or, you could add code in the included script that calls a method to whatever has been waiting for it.
Or, you could look at how jQuery does something similar, look for where the ajax method is defined, specifically these parts...
var script = document.createElement("script");
// then later ...
script.onload = script.onreadystatechange = function(){
if ( !done && (!this.readyState ||
this.readyState == "loaded" || this.readyState == "complete") ) {
// do processing
head.removeChild( script );
}
};
// ...
head.appendChild(script);
Could you possibly add a function call to your script files, so that when they're run, they call the function that does your
document.write( myValue );
So that script1.js would be
var myValue = 1;
scriptLoaded();
and your main file would have:
function scriptLoaded(){
document.write( myValue );
}