incubator-callback-dev mailing list archives

Site index · List index
Message view « Date » · « Thread »
Top « Date » · « Thread »
From "Filip Maj (JIRA)" <>
Subject [jira] [Commented] (CB-514) Do we need to monkey patch addEventListener()?
Date Wed, 02 May 2012 20:56:56 GMT


Filip Maj commented on CB-514:

I've looked into this a little bit more, and been working on a [branch in my repo|].

I stumbled upon an issue, though. For example, in the battery API, we need to know when the
first handler to a {{window}} or {{document}} event gets added, and when the last handler
gets removed, so that we can tell the native code to start and stop listening for battery
events. I can't see a way to do that unless we monkeypatch {{addEventListener}} et al.

Any ideas, Pat?
> Do we need to monkey patch addEventListener()?
> ----------------------------------------------
>                 Key: CB-514
>                 URL:
>             Project: Apache Callback
>          Issue Type: Bug
>          Components: CordovaJS
>            Reporter: Patrick Mueller
>            Assignee: Filip Maj
> discussion here:
> I noticed in cordova.js we override the following messages on window/document:
> {noformat}
> document.addEventListener = function(evt, handler, capture) {...}
> window.addEventListener = function(evt, handler, capture) {...}
> document.removeEventListener = function(evt, handler, capture) {...}
> window.removeEventListener = function(evt, handler, capture) {...}
> {noformat}
> aka as "monkey patching".  
> Apparently, we aren't sure why we're doing this.  My guess is that we've done this in
the past when dispatching user-land events wasn't possible, and so trapping listeners was
the only way to get the listeners so you could send them events.
> It would be nice to remove this monkey patching, if we can, by using:
> {noformat}
> event = document.createEvent('Events')
> event.initEvent(blah)
> window.dispatchEvent(event)
> // or document.dispatchEvent(event)
> {noformat}
> We'll need to figure out if this works on all our platforms.  Even if it doesn't work
on all of them, I think we should only use monkey patching on platforms that we have to.

This message is automatically generated by JIRA.
If you think it was sent incorrectly, please contact your JIRA administrators:!default.jspa
For more information on JIRA, see:


View raw message