On Dec 22, 2008, at 8:41 PM, Ian Hickson wrote:
On Tue, 5 Aug 2008, Ian Hickson wrote:
I would like some input from browser vendors.
Right now, if you navigate an iframe to a document, and take a
reference to a method defined in that document, and then navigate
that
iframe to another document, and then call the method, browsers
differ in
what they do.
There are several behaviours:
- In one browser, the Window object changes with each navigation,
and the global object is that object, and the method runs fine.
- In one browser, the method call fails, saying that methods can't be
called while the document that defined them isn't the active
document
of the browsing context whose global object is the method's.
- In one browser, the Window object acts as a kind of view on the
global
object, which changes with each navigation, leading the method to
see
the original global object in its scope chain, but the new one if
it
uses the 'window' object. (In this environment, 'this' at the top
scope
returns the 'window' object, not the global object.)
- In one browser, the global object and the Window are the same,
but the
global object is totally wiped out with each navigation,
preventing the
method from accessing its global object's data. (In this browser,
the
results are slightly different when navigating top-level windows
instead of frames.)
These results were derived from:
http://damowmow.com/playground/demos/global-object/004.html
I propose to adopt the second behaviour above. It seems by far the
simplest behaviour to define and implement. Are there any
objections to
this? Given the lack of interoperability here, it seems like we
aren't
really constrained to pick something due to compatibility.
The change would be that if a method is invoked when the script
execution context that the method was running in has a Document
object
that is not the active Document object of its browsing context, then
that method immediately throws an exception. Access to variables
obtained from such script execution contexts would be unaffected.
I've now done this.
I just replied to your earlier email on the topic, which I missed
before. I would be against this change, due to likely performance cost.
Regards,
Maciej
