ps, I also tried the curry() method mentioned above by ken to no
avail...
On May 16, 12:08 pm, "[EMAIL PROTECTED]" <[EMAIL PROTECTED]>
wrote:
> heh, sorry but I've got another related problem where the onclick
> assignment doesn't seem to take to the element.
>
> I have a function, and inside this function I have another function
> assigned to a var scoped variable name. This function creates and
> returns a <a> element with a <img> element appended inside it. The in
> the original function append the <a> element inside a <div> element.
> Here is some of the code:
>
> var deletef = function(id) {
> var deleteImg = document.createElement('img');
> deleteImg.id = id;
> deleteImg.src = '';
> deleteImg.alt = 'delete';
> var deleteLink = document.createElement('a');
> deleteLink.id = id;
> deleteLink.href = "javascript:;";
> deleteLink.onClick = (function(id){
> return function(){alert(id + " deleted...");}
> })(id);
> deleteLink.appendChild(deleteImg);
> return deleteLink;
> }
>
> I am then calling the function inside a appendChild function like so:
> div.appendChild(deletef(id));
>
> Does any one see here why the onclick assignment doesn't seem to work?
>
> On May 16, 11:12 am, "[EMAIL PROTECTED]" <[EMAIL PROTECTED]>
> wrote:
>
> > Thank you very much guys. Your suggestions worked for me.
>
> > @ T.J.
> > You explanations were very insightful. I think that I understand
> > javascript a little better now, thank you.
>
> > On May 16, 4:33 am, "T.J. Crowder" <[EMAIL PROTECTED]> wrote:
>
> > > Hi,
>
> > > Both Ken and kangax have answered the practical question you posed,
> > > but you're probably wondering why your code didn't work. :-) It's
> > > because in this line of code:
>
> > > > item.onclick = function(){fc.selectArticle(id,headline);};
>
> > > ...you're assuming that 'id' and 'headline' become fixed at that point
> > > in time, that you're burning their *values* into the closure function
> > > (the onclick handler) at the point the function is defined. That's
> > > not how closures work. They work by giving the function enduring
> > > *access* to the things in scope where it's defined. So for instance:
>
> > > function chatter()
> > > {
> > > var closures;
> > > var i;
> > > var msg;
> > > var closure;
>
> > > closures = [];
> > > for (i = 1; i <= 5; ++i)
> > > {
> > > msg = "This is message #" + i;
> > > closures.push(function() { alert(msg); });
> > > }
>
> > > for (i = 0; i < closures.length; ++i)
> > > {
> > > closure = closures[i];
> > > closure();
> > > }
>
> > > }
>
> > > This *doesn't* show five alerts saying "This is message #1", "This is
> > > message #2", etc. It shows five alerts saying "This is message #5",
> > > because the functions access the 'msg' variable dynamically when
> > > they're *called*, and by the time they're called, msg is "This is
> > > message #5". This is incredibly powerful, but can be a bit surprising
> > > when you first look at it, especially when the closure lives on after
> > > the function returns and you think that the local vars have
> > > disappeared (they haven't, the closure preserves them). So this works
> > > the same way and has the same result:
>
> > > function chatter()
> > > {
> > > var closures;
>
> > > closures = createChatter();
> > > doChatter(closures);}
>
> > > function createChatter()
> > > {
> > > var closures;
> > > var i;
> > > var msg;
>
> > > closures = [];
> > > for (i = 1; i <= 5; ++i)
> > > {
> > > msg = "This is message #" + i;
> > > closures.push(function() { alert(msg); });
> > > }
>
> > > return closures;}
>
> > > function doChatter(closures)
> > > {
> > > var closures;
> > > var i;
> > > var closure;
>
> > > for (i = 0; i < closures.length; ++i)
> > > {
> > > closure = closures[i];
> > > closure();
> > > }
>
> > > }
>
> > > Note that the 'msg' variable lives even though createChatter() has
> > > returned; each closure keeps a reference to the scope where it was
> > > defined, and so that scope is preserved in memory even when it would
> > > have been released if there were no closures involved. (The other
> > > local vars to createChatter() also live on; but nothing uses them, so
> > > that's just wasted space.)
>
> > > More on closures in my blog (which sadly I haven't had time to post to
> > > lately):http://blog.niftysnippets.org/2008/02/closures-are-not-complicated.ht...
>
> > > This post may also be
> > > useful:http://blog.niftysnippets.org/2008/03/horror-of-implicit-globals.html
> > > ...as you have an implicit global variable 'i' in your code which you
> > > almost certainly intended to be local to your "result" function. ;-)
>
> > > Hope this helps,
> > > --
> > > T.J. Crowder
> > > tj / crowder software / com
>
> > > On May 15, 10:57 pm, "[EMAIL PROTECTED]" <[EMAIL PROTECTED]>
> > > wrote:
>
> > > > Hi all,
> > > > I am having trouble with my variable assignments always becoming the
> > > > last variable inside my loop.
>
> > > > var populateAvailableContent = Class.create(methodCall,
> > > > {
> > > > initialize: function($super, name, message) {
> > > >
> > > > $super(name,'getAllContent','Loading...')
> > > > },
> > > > result: function(ret) {
> > > > var div = $('articles');
> > > > div.innerHTML = null;
> > > > var rowCount = ret.getRowCount();
> > > > for (i=0;i<rowCount;i++) {
> > > > var item =
> > > > document.createElement('div');
> > > > var id = ret.id[i]
> > > > var headline = ret.headline[i];
> > > > var html = headline + "<hr />";
> > > > item.id = "item";
> > > > item.onclick =
> > > > function(){fc.selectArticle(id,headline);};
> > > > item.innerHTML = html;
> > > > div.appendChild(item);
> > > > }
> > > > }
> > > > })
>
> > > > In this scenario, id and headline are always becomes the last value in
> > > > the loop and that is what is passed in the fc.selectArticle()
> > > > function. I've tried a few different possible solutions I've found on
> > > > the web, but none seemed to work. I decided to try and give the bind()
> > > > function a go around but I can't seem to figure out how to use it in
> > > > my situation.
>
> > > > Any help would be greatly appreciated.
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