? So if the event is attached with:
this.textboxRect.addEventListener("click",this,false);
and I use your exact "bind" method,
then the exact code for the handler is:
textbox.prototype.handleEvent=bind(textbox,function(evt){
alert(this);
});
The alert gives:
[EMAIL PROTECTED]
"this" is still not working... What is wrong here?
Cameron McCormack-4 wrote:
>
> Hi.
>
> snapper:
>> How can I get object reference instead of window reference in
>> this.handleEvent(evt)?
>>
>> I have ECMAScript in a Batik SVG application using widgets. I noticed
>> that
>> the Carto textbox does not work in Batik due to event handing problems,
>> so I
>> am rewriting it. Andreas attached event handlers using the root element
>> in
>> all cases, which causes many problems. I am attaching events to the
>> widget
>> elements instead like this:
>>
>> this.textboxRect.addEventListener("click",this._handleEvent,false);
>>
>> The event handler in the textbox object does receive the event, but
>> inside
>> the this.handleEvent(evt), the "this" refers to the window object. We
>> really
>> want the reference to the textbox object.
>>
>> How can I get the reference to the textbox object inside the event
>> handler
>> in this case?
>
> This is normal behaviour: when you refer to this._handleEvent, it is
> just a reference the function that has been stored in the 'this'
> object–it has lost its association with the object. If you want to be
> able to access the 'this' object from _handleEvent, you can refer to
> the object from the closure when you assign it. For example:
>
> blah._handleEvent = function(evt) {
> // refer to 'blah' in here
> };
>
> I often use a function to bind the the 'this' variable to an object of
> my choosing, so that I can do what you want to do.
>
> function bind(_this, f) {
> var _ = function() {
> return f.apply(_this, arguments);
> };
> _.toString = function() {
> return "/* bound function */\n" + String(f);
> };
> return _;
> }
>
> and then:
>
> blah._handleEvent = bind(blah, function() {
> // now 'this' inside here will always refer to 'blah',
> // regardless of how the function was called.
> });
>
> --
> Cameron McCormack, http://mcc.id.au/
> xmpp:[EMAIL PROTECTED] ▪ ICQ 26955922 ▪ MSN [EMAIL PROTECTED]
>
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