Re: Implementing delegation

FROM : Tobias Peciva
DATE : Sun Nov 21 21:35:13 2004

On 20/11/2004, at 12:12 PM, Bruce Toback wrote:

> On Nov 19, 2004, at 4:08 PM, Bruce Toback wrote:
>

>> Okay, that looks very much like what I'm doing. But using the code
>>
>>    if ([delegate
>> respondsToSelector:@selector(myObject:wantsToTellYou:)])
>>      [delegate myObject: self wantsToTellYou: something];
>>
>> I get the warning
>>
>>  cannot find method '-myObject:wantsToTellYou:'; return type 'id'
>> assumed

>
> I figured out the difference: the sample on cocoadevcentral declares
> the interface to the delegate as a category on NSObject. This makes
> the compiler happier, since it has an interface.


Or you could just use something along the lines of:
if([delegate respondsToSelector:...])
{
    [delegate performSelector:...];
}

Invocations would do the job as well.

That said, it would be interesting to know what Apple's implementation
looks like.

Cheers,
Tobias Peciva
Pharos Systems