Javascript, the DOM, addEventListener and attachEvent
While scripting the voting widget for the post-May-1st CSS Reboot site, I had some problems with attaching events cross-browser, caused almost entirely by some incorrect code posted on another site.
Because inline event handlers are, like, so 1999, I am using a function to attach the mouseOver and mouseOut events to a series of images; and due to Internet Explorer’s non-support of the standard addEventListener method, I am branching the code to detect support of the available options:
if (el.addEventListener) {
el.addEventListener ("mouseover",myFunction,false);
el.addEventListener ("mouseout",myFunction,false);
} else if (el.attachEvent) {
el.attachEvent ("onmouseover",myFunction);
el.attachEvent ("onmouseout",myFunction);
} else {
el.onmouseover = myFunction;
el.onmouseout = myFunction;
}
The problem was caused by the example I was working from using the wrong syntax for the attachEvent method – it missed out the leading “on” from the first argument (the name of the event).
Eventually I worked out what the problem was (with the help of this handy cross-browser attachEvent function), but it just goes to show you can’t take everything you read on the internet at face value – even the geeks get it wrong sometimes!
Filed under: Javascript.
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Comments
- Jordan Arentsen
- 832 days ago
- Which technique did you finally decide to use? The code you provided, or the attachEvent function from the link?
- #1
- Matthew Pennell
- 832 days ago
- Jordan: I now use an all-purpose Event object – you can find it in use on this page
- #2
- adix
- 734 days ago
Interesting.
But, there is a difference between IE5.0 and the other IE’s.- #3
