Reputation: 615
I've been putting together a lightweight event utility for cross-browser event handling, but have come across a rather high hurdle I can't quite jump over. It's concerning the srcElement property in IE9, which just isn't working for me!
Currently, my utility looks something like this (the srcElement is the 3rd code block):
var bonsallNS = new Object();
bonsallNS.events = {
addEvent: function (node, type, func) {
if (typeof attachEvent != "undefined") {
node.attachEvent("on" + type, func);
} else {
node.addEventListener(type, func, false);
}
},
removeEvent: function (node, type, func) {
if (typeof detachEvent != "undefined") {
node.detachEvent("on" + type, func);
} else {
node.removeEventListener(type, func, false);
}
},
target: function (e) {
if (typeof srcElement != "undefined") {
return window.event.srcElement;
} else {
return e.target;
}
},
preventD: function (e) {
if (typeof srcElement != "undefined") {
window.event.returnValue = false;
} else {
e.preventDefault();
}
}
}
Now, using the following test script below works fine in Chrome and Firefox, but returns the evtTarget to be undefined in IE when I try to alert it. I have NO idea why, so any help would be greatly appreciated! See below code:
var gClick = document.getElementById("clickme");
var gCount = 0;
function mssg(e){
var evtTarget = bonsallNS.events.target(e);
alert("it worked, target: " + evtTarget);
gCount++
if (gCount > 2){
bonsallNS.events.removeEvent(gClick, "click", mssg);
}
}
function setUp(){
bonsallNS.events.addEvent(gClick, "click", mssg);
}
bonsallNS.events.addEvent(window, "load", setUp);
Like I say, everything else works except for the event source in IE!!
Upvotes: 1
Views: 2367
Reputation: 816384
The variable srcElement
will always be undefined
unless it's defined in a higher scope. But it will never refer to event.srcElement
.
You can solve this problem in two ways: Either check whether e
or e.srcElement
are not defined, or whether window.event
and window.event.srcElement
are defined.
if (typeof e === "undefined" || typeof e.srcElement === "undefined") {
// or
if (typeof window.event !== "undefined" &&
typeof window.event.srcElement !== "undefined") {
You can also shorten the whole function to:
target: function (e) {
e = e || window.event;
return e.target || e.srcElement;
}
Upvotes: 1