Re: [Pyobjc-dev] How to get Python class into Objc namespace

[Steve S. <sst...@ma...>]

On May 8, 2008, at 9:44 PM, Bill Bumgarner wrote:

> On May 8, 2008, at 5:38 PM, Steve Steiner wrote:
>> 	If someone will just point me to the right resource, I'll blog it  
>> and
>> make it findable by the next poor sot.
>
> 	[[NSClassFromString(@"MyPythonClass") alloc] init];
>
> Your challenge will be where you define the method prototypes to  
> keep the compiler happy.
>
> Personally, I would create a dummy class that has NO methods, then  
> declare categories against that dummy class that has all of the  
> methods w/appropriate signature that are needed... then declare the  
> result of the above to be a pointer to an instance of that class.
>
> Makes the compiler happy and the runtime doesn't care.

That all worked, thanks!  I'm finishing up blog entries and will post  
back to the list when I'm finished.

> Unless you are jumping through hoops to declare the method  
> signatures, everything will be of an object type.
>
> If you want to provide subclasses of specific objc classes that are  
> implemented in python, then declare an abstract subclass that  
> contains all the method declarations and implementations that do  
> nothing, then subclass that from Python.  That'll give the bridge  
> all (if you run gen_bridge_metadata, if needed) to do the  
> conversions across the bridge for the types that need it.

Even though I went through this all, including the gen_bridge_metadata  
build step, it turned out that nothing I was doing wouldn't be  
automatically bridged.  Cool!

The mistake I made that lead me down this path was that I didn't  
realize that objc.ivar() just set up a KVC hook and thought I was  
doing something wrong when I couldn't access my Python ivars.

What I realized, as I was working through all of this, is that what  
I'd really like to do is insure that my Python class implements a  
protocol.

This is a plug-in architecture and I really need to verify that what  
is claiming to implement required functionality actually does.

I've set up:

	SSDummyProtocol -- with a couple of dummy "- (NSObject) getData;"  
style declarations
	SSDummyObject -- declared as implementing the SSDummyProtocol
	SSDummyObjectPython -- with SSDummyObject as the parent, and I've  
implemented all the required methods, all in Python.

What is the correct way to call conformsToProtocol: on my  
SSDummyObjectPython instance?

I've tried several ways and they all result in (null).

Thanks,

S