It is a little bit different from window.open defined by w3c. As window.open,
the onload, onerror events can be embedded in the html page, they will be
automatically attached to DOM when parsing the page, there is no need to add
the event handler by separate calls, so no event will be missed.
In fact, if calling the similar code shown below on a regular page, the onload
method will not be called.
var ref = window.open('http://apache.org');
ref.addEventListener('loadstart', function() { alert(event.url); });
The design should not heavily depend on the current browser's javascript thread
implementation. Besides it is not safe to always assume the event will only be
fired asynchronously from native code. For example, if invalid parameters are
passed to open method, the validator may need to call onError to report the
error, it will not work if onError event handler cannot be added before the
operation.
Jonathan
-----Original Message-----
From: [email protected] [mailto:[email protected]] On Behalf Of Braden
Shepherdson
Sent: Tuesday, May 28, 2013 11:10 AM
To: [email protected]
Subject: Re: inAppBrowser API issue
If the event really did fire before the event listener was added, the
Javascript engine is broken. When the event is triggered (which may happen
in another browser thread or something) it will be added to the event queue
in the Javascript engine. That event will not be processed until the
currently executing Javascript chunk is done - the next time the Javascript
cedes control (setTimeout, returning from all functions, etc.). That won't
happen until after the event handler is attached in the second line.
We didn't design this API, it's the same window.open API is is used
elsewhere. Cordova tends to use existing W3C specs where appropriate.
Braden
On Tue, May 28, 2013 at 10:47 AM, Li, Jonathan <[email protected]> wrote:
> Not sure whether this is a right place for this issue, but the javascript
> interface for InAppBrowser does not make much sense. The below code is
> from cordova document:
>
> var ref = window.open('http://apache.org', '_blank', 'location=yes');
> ref.addEventListener('loadstart', function() { alert(event.url); });
>
> The event handler is added after the open method is returned, so it is
> possible the event gets fired before developer has a chance to add the
> event handler for the open operation. Although it is async operation, it
> is still a good design, and may cause timing or other issues depending on
> native side implementation.
>
> Just wonder whether this is a known issue, or could it be changed to a
> better interface design?
>
> Thanks
> Jonathan
>
>
