Subclassing an Objective-C class

The previous post describe how to use python class from Objective C. Now, we want to create a python class that subclass from an Objective-C class:

@interface ObjCClass : NSObject {

NSString *aString;

}

@property (retain) NSString *aString;

@end

@implementation ObjCClass

@synthesize aString;

- (id) init

{

self = [super init];

if (self != nil)

{

aString = @"hello from obj-c";

}

return self;

}

@end

We modify the python file by adding a subclass declaration:

from Foundation import *

import objc

ObjCClass = objc.lookUpClass("ObjCClass")

class TestClass (ObjCClass):

def doit_(self, input):

print "sent from obj-C:", input

print "obj-C attribute:", self.aString()

self.setAString_("python modified attribute")

return "hello from Python"

The ObjCClass = objc.lookUpClass("ObjCClass") responsible for finding class in objective C. Note that when we use this, it is impossible to run this Python script alone.