WEB STANDARDS CREATIVITY

The addEvent function primes the web page. It tells the browser what it needs to run (which JavaScript function) and when
(on what event—for example, when the page loads or when something gets clicked). Here it is:
function addEvent(elm, evType, fn, useCapture)
{
if(elm.addEventListener)
{
elm.addEventListener(evType, fn, useCapture);
return true;
}
else if (elm.attachEvent)
{
var r = elm.attachEvent('on' + evType, fn);
return r;
}
else
{
elm['on' + evType] = fn;
}
}
Now if that looks like gobbledygook to you, don’t worry. You don’t need to understand everything it does or how. You simply
need to know that it has been created to work around some cross-browser JavaScript issues, and it allows you to call it
using three parameters:
What element you are dealing with (elm)
What the event is (click, load, focus) (evType)
What JavaScript function you want it to do when that element has that event triggered (fn)
And here’s an example of how you would call it:
addEvent(window, 'load', addPrintLinks, false);
Or, in plain English, when the window (or, to be precise, the document in this window) has loaded, please run the
addPrintLinks function. This function has yet to be built, so just to test that it works, I’ve placed a simple alert there for
the time being:
function addPrintLinks()
{
alert("Here's where the cool stuff will happen");
}
addEvent(window, 'load', addPrintLinks, false);
The alert looks like Figure 8-3.
chapter 8 Print Magic: Using the DOM and CSS to Save the Planet
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