Missing something for Cocoa/PyObjC Distributed Objects

Question

I'm trying to make a simple example using Distributed Objects with PyObjC. On the server side I have (in Xcode):

class VendedObject(NSObject):
    @objc.signature('@24@0:')
    def speak(self):
        return 'woof'

class TalkAppDelegate(NSObject):      

    def applicationDidFinishLaunching_(self, sender):
        NSLog("Application did finish launching.")
        conn = NSConnection.defaultConnection()
        NSLog("Creating connection")

        obj = VendedObject.alloc().init()
        print obj.description()
        conn.setRootObject_(obj)
        result = conn.registerName_("my_server")
        if not result:
            NSLog("Failed to register Name")
        #conn.setDelegate_(self)
        NSLog(conn.description())

When I run it I get:

2011-01-27 10:27:55.695 Talk[34432:a0f] Application did finish launching.
2011-01-27 10:27:55.698 Talk[34432:a0f] Creating connection
<VendedObject: 0x3e45970>
2011-01-27 10:27:55.701 Talk[34432:a0f] (** NSConnection 0x28f2030 receivePort <NSMachPort: 0x28f2160> sendPort <NSMachPort: 0x28f2160> refCount 2 **)

On the client side I have:

class ListenAppDelegate(NSObject):      

    def applicationDidFinishLaunching_(self, sender):
        NSLog("Application did finish launching.")
        proxy_obj = NSConnection.rootProxyForConnectionWithRegisteredName_host_(
            "my_server", None)
        if not proxy_obj:
            print 'Did not get an object from the server.'
        else:
            print proxy_obj.description()
            print proxy_obj.speak()

I get:

2011-01-27 10:28:35.821 Listen[34460:a0f] Application did finish launching.
<VendedObject: 0x3e45970>
2011-01-27 10:28:35.829 Listen[34460:a0f] -[OC_PythonString initWithBytes:length:encoding:]: unrecognized selector sent to instance 0x3635130
2011-01-27 10:28:35.832 Listen[34460:a0f] -[OC_PythonString initWithBytes:length:encoding:]: unrecognized selector sent to instance 0x3635130

I'm missing something but don't know what?

EDIT: modified to use what I think is the correct signature, and show the new problem that arises. Thanks.

Answer 1

Answering my own question, sorry. It seems to be a problem with PyObjC. I rewrote the Server in Objective-C:

#import "VendAppDelegate.h"

@interface VendedObject:NSObject {}
-(NSString *) speak;
@end

@implementation VendedObject

-(NSString *) speak {
    return @"woof";
}
@end

@implementation VendAppDelegate

@synthesize window;

- (void)applicationDidFinishLaunching:(NSNotification *)aNotification {
    NSAutoreleasePool *pool ;
    pool = [[NSAutoreleasePool alloc] init];
    VendedObject *obj;
    obj = [[[VendedObject alloc ] init] autorelease];
    NSLog(@"%@", [obj description]);

    NSConnection *conn;
    conn = [[[NSConnection alloc] init] autorelease];
    [conn setRootObject:obj];
    BOOL result;
    result = [conn registerName:@"my_server"];
    if (!result) {
        NSLog(@"Failed to register Name");
    }
    else {
        NSLog(@"%@", [conn description]);
    }
    [pool drain];
}

@end

And run it with this output:

2011-01-27 11:45:14.252 Vend[36530:a0f] <VendedObject: 0x1001326f0>
2011-01-27 11:45:14.254 Vend[36530:a0f] (** NSConnection 0x1004527f0 receivePort <NSMachPort: 0x100452a80> sendPort <NSMachPort: 0x100452a80> refCount 1 **)

I do this from Python:

from Foundation import *

proxy_obj = NSConnection.rootProxyForConnectionWithRegisteredName_host_(
    "my_server", None)
if not proxy_obj:
    print 'Did not get an object from the server.'
else:
    print proxy_obj.description()
    print type(proxy_obj)
    print proxy_obj.speak()

Output:

<VendedObject: 0x1001326f0>
<objective-c class NSDistantObject at 0x7fff70a64868>
woof