All the example scripts I’ve found so far will only work if the parent page remains the same. I.e. you’re testing whether the pop up is already open, but applying this test on the document/page that originally opened the popup. What I’m looking to do is subtly different – so the pop up remains open so as you are browsing Cohere you can add ideas to make connections between.

I would think that this ought to be possible, because if you open a popup window with the same name as an existing one, the old one will get overwritten – so it ‘knows’ that the pop up exists. Plus, this is all running from the same domain, so there won’t be any cross domain issues.

If anyone has any pointers as to how to achieve this, it would be much appreciated. Or if you have other suggestions for how the same results could be achieved. Cheers

I’m really hoping to get this fixed very soon, but haven’t yet found the root cause, I can reliable recreate the issue, so just need to find why it’s happening.

Plus I need to get my presentation for next weeks OpenLearn conference written sometime soon!

Update (29th Oct)… I have now got the problem resolved, though still don’t know the real root cause. I fixed it by going back through the changes I’ve made recently and seeing at what point the error started occuring.
The change which appears to have been causing the error was when I switched from using <a href=”javascript:….”> to using (what I thought was the proper way!) of adding/removing event listeners. The actual problem occured with the call to detach event, although it didn’t fail everytime – it would work for the first few times and then randomly cause the browser to crash. I did notice that the carsh would only happen if I had the MSG client and the referring site (the one with the users presence icon) open at the same time, if only one was open the crash wouldn’t occur.

For info this was the code that was causing problems:

var oldImg = presenceNode.firstChild;
//remove any current listeners
if(oldImg.removeEventListener){ // Mozilla, Netscape, Firefox
oldImg.removeEventListener('click', launchClick, false);
oldImg.removeEventListener('click', readMessageClick, false);
} else { // IE
oldImg.detachEvent('onclick', launchClick);
oldImg.detachEvent('onclick', readMessageClick);
}


So I replaced this with the code below that just alters the location and title of the link (also a bit of adjusting to add the <a> in):

var oldAnchor = presenceNode.firstChild;
var newAnchor = oldAnchor.cloneNode(true);
newAnchor.href = "javascript:readMessageClick();";
newAnchor.title = MSGAPIconf.str_oneMessageUnread;

So, glad to have got it fixed, but would be even better to know why this was really happening at all!

Update Number 2 (1st Nov) – The fix has now been made live on the MSG-OpenLearn servers.

function init(){
	var myUl = document.getElementById("test");

	for(var i=0; i<10; i++){
		var myLi = document.createElement("li");
		mySpan = document.createElement("span");
		mySpan.setAttribute("id","myspan"+i);
		myLi.appendChild(mySpan);
		myUl.appendChild(myLi);

		mySpan.appendChild(document.createTextNode(i));
		if(mySpan.addEventListener){ // Mozilla, Netscape, Firefox
			mySpan.addEventListener('click', function(){test(i);}, false);
		} else { // IE
			mySpan.attachEvent('onclick', function(){test(i);});
		}
	}
}

function test(myNum){
	alert(myNum);
}

This produces an unordered list of 10 items – (0-9), but when you click on any of the numbers the alert returns ’10′, rather than the expected 0-9 depending on which on you click. I could understand if it returned ’9′ for every item in the list – but why 10?? I spent ages fiddling with this, but never did find what was actually causing this to occur – it seems like a bug to me – unless I’m just misunderstanding how the addEventListeners work? Maybe something to do with the fact I’m using anonymous functions?

If anyone has an explanation (or can point me to an explanation) as to what I’ve done wrong it would be much appreciated.

For info I managed to get around the problem by using the code below instead, though I’d still like to know what was wrong with my original code!

function init(){
	var myUl = document.getElementById("test");

	for(var i=0; i<10; i++){
		var myLi = document.createElement("li");
		mySpan = document.createElement("span");
		mySpan.setAttribute("id",i);
		myLi.appendChild(mySpan);
		myUl.appendChild(myLi);

		mySpan.appendChild(document.createTextNode(i));
		if(mySpan.addEventListener){ // Mozilla, Netscape, Firefox
			mySpan.addEventListener('click', eventHandler, false);
		} else { // IE
			mySpan.attachEvent('onclick', eventHandler);
		}
	}
}

function eventHandler(e){
	var e=e? e : window.event;
	var el=e.target? e.target : e.srcElement;
	alert(el.id);
}

var oldImg = myNode.firstChild;
var newImg = document.createElement(‘img’);
newImg.src = "/new/path/to/image/jpg";
newImg.alt = "my new alt text";
           
myNode.replaceChild(newImg,oldImg);

Note that this is very basic example and probably only works when ‘myNode’ has a single child node which is of type ‘img’.