- MOZILLA, FIREFOX, SEAMONKEY
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addEventListener attachEvent - Pass parameters to event-function
If you manipulate a DOM object's events with addEventListener (Mozilla, Firefox) or attachEvent (Internet Explorer),
you can't pass parameters to the event function.
But you can get information of the object where the event occured. E.g. you can do stuff dependent
on the "id" of an object, or you can set any additional flags within the object and do stuff dependent on
these flags.
Here we have the code for attaching the events:
if(window.addEventListener){ // Mozilla, Netscape, Firefox
object.addEventListener('mouseover', testevent, false);
object.addEventListener('click', testevent, false);
object.myflag = "test";
object.mydata = "123";
} else { // IE
object.attachEvent('onmouseover', testevent);
object.attachEvent('onclick', testevent);
object.myflag = "test";
object.mydata = "123";
}
The function "testevent" contains all code to access the "id", "name" etc. and all own flags:
function testevent(evt){
var e_out;
var ie_var = "srcElement";
var moz_var = "target";
var prop_var = "myflag";
// "target" for Mozilla, Netscape, Firefox et al. ; "srcElement" for IE
evt[moz_var] ? e_out = evt[moz_var][prop_var] : e_out = evt[ie_var][prop_var];
alert(e_out);
prop_var = "mydata";
evt[moz_var] ? e_out = evt[moz_var][prop_var] : e_out = evt[ie_var][prop_var];
alert(e_out);
}
Conclusion: If you set appropriate flags when attaching an event to an object, you have the
possiblity to do actions dependent on these flag when the actual event occurs.
Therefore it is not necessary to pass parameters directly when attaching the event, since
those parameters either do not change anyway, or if the parameters are dynamically created,
those dynamic parameters can be read out in the function "testevent".
Last-Modified: Wed, 05 Jul 2006 18:29:04 GMT
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