Re: [Pyobjc-dev] Controller Layer

[Carlos P. <car...@ma...>]

Hi,

I sent the following email to Bill (b.bum):

> There is something fundamental about the key-value binding that I don' 
> t understand. I have been using it extensively in objective-c, but I 
> can't seem to be able to use it to connect to a nib in PyObjC. Here is 
> a sample python class I use:
>
> # Converter.py:
> import objc
>
> class Converter(objc.runtime.NSObject):
>     def getAmount(self):
>         return "1"
> if __name__ == "__main__":
>     AppHelper.runEventLoop()
>
>
> Now I create a MainMenu.nib which has a window with a single 
> NSTextField. In the nib, I instantiate an empty definition of 
> Converter in the nib. Converter is defined as a subclass of NSObject. 
> I then create an instance of NSController, add an "amount" key and 
> bind the value of the text field to it. Finally, I connect the 
> Converter instance to the "content" outlet of the NSController. This 
> is the exact setup I used in an obj-c version of this test.
>
> I run the following buildapp.py script to make this into a program
>
> from bundlebuilder import buildapp
> buildapp(
>     mainprogram = "Converter.py",
>     resources = ["English.lproj" ],
>     nibname = "MainMenu",
> )
>
> The result is a sementation fault. What am I doing wrong?

He responded as follows:

> This'd be an objc/c problem -- if the app is crashing and giving you 
> the "submit crash report" panel, then click "submit" and copy/paste 
> the backtrace found in the resulting window.  If not, have a look in 
> ~/Library/Logs/ and see if there is a log there.
>
> Otherwise, you'd need to run under gdb.
>
> Try adding...
>
>     def automaticallyNotifiesObserversForKey_(self, aKey):
>         return NO
>
> ... to your class and see if that fixes the problem.  Also, make sure 
> you are running pyobjc based on the latest source from CVS -- there 
> have been many updates that are 10.3 specific.
>
> Finally, we should continue this on pyobjc-dev.  I'm really busy @ 
> Apple and will likely not have time to answer you in the coming days 
> -- but the folks on pyobjc-dev will answer and they are really 
> friendly/knowledgeable.

Overloading the method did in fact fix the problem. I thought this 
might be useful to someone else.

Carlos