Rob,
The solution that David provided me indeed fixed my problem, although
I'd love to hear any alternative methods if you have any.
As far as initializing variables with null or 0, it's just a bad
habit. The original code I had written I did use the images
collection, although as I was messing with it I changed to the
getElementsByTagName method instead to see if that was the issue. It
wasn't, but I didn't change it back. Also, by using the $$ method, it
only returned to me the images with that particular tooltip, which is
quite helpful and eliminated the need to test whether that attribute
existed or not.
I'm still learning about how to handle scope when calling functions
within objects, etc. and I'm still pretty fresh to prototype and any
form of OOP-type programming in javascript so if you would care to
elaborate on the alternatives you mentioned, I'm interested.
On Jun 15, 4:30 am, RobG <[EMAIL PROTECTED]> wrote:
> On Jun 14, 7:32 am, Cgnost <[EMAIL PROTECTED]> wrote:
>
> > I've created a custom tooltip function to be used on a website. I'm
> > trying to code it in such a way that by giving any img tag an
> > attribute with tooltip="productid" it will attach the correct
> > onmouseover and onmouseout event.
>
> > Here is the code:
>
> > loadEvents: function() {
> > var images = document.getElementsByTagName("img");
>
> It seems David has already given you a solution you are happy with,
> however it's worth pointing out that the document already has an
> images collection ready for you to use:
>
> var images = document.images;
>
> It's a live collection, so as you add/remove images, they are
> automatically added/removed from the collection.
>
> Also, the number of lines of code is not any indicator of efficiency
> or speed. You will often find that looping over a collection is much
> quicker than using $$, and faster again than .each. If performance is
> an issue (and maybe it isn't for you) consider the above.
>
> > var myElement = null;
>
> There is rarely any point in initialising a variable as null, if you
> use:
>
> var myElement;
>
> it is assigned a value of undefined, which is suitable in nearly all
> cases.
>
> > var myProductID = 0;
>
> Same here. You are going so assign a value of the tool tip, so there
> doesn't seem much point in assigning a value of zero.
>
> > for (var i = 0; i < images.length; i++) {
> > myElement = images[i];
> > if (myElement.hasAttribute("tooltip")) {
> > myProductID =
> > myElement.getAttribute("tooltip");
> > Event.observe(myElement, 'mouseover',
> > function()
> > { productTooltip.show(myProductID,myElement); });
>
> Here is where your issue comes from - both myProductID and myElement
> form closures back to their respective variables that are associated
> with the function's execution object. Their value in all cases will
> be whatever value was last assigned them before the function finished
> so all your handlers will have references to the same value.
>
> There are alternatives to that proposed by David - but if it suits,
> use it.
>
> --
> Rob
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