AVAudioplayer and Blocks - ios

Question

As Apple encourages the usage of blocks, and i wanted to do a series of animations, with sound output in between them which is basicly like a todolist, i wanted to implement this using blocks.
unfortunatly AVAudiosplayer doesnt appear to support onCompletion blocks, in the manner UIAnimation does.
So i thought it would be cool to add that support to the AVAudioplayer.
so what ive dont is this
header
#import <AVFoundation/AVFoundation.h>
#interface AVAudioPlayer (AVAudioPlayer_blockSupport)
typedef void(^AVPlaybackCompleteBlock)(void);
#property (nonatomic, copy) AVPlaybackCompleteBlock block;
-(id)initWithContentsOfURL:(NSURL*)pathURL error:(NSError**)error onCompletion:(AVPlaybackCompleteBlock) block;
-(void)setBlock:(AVPlaybackCompleteBlock)block;
-(AVPlaybackCompleteBlock)block;
-(void) executeBlock;
#end
and the m file
#import "AVAudioPlayer+blocks.h"
#implementation AVAudioPlayer (AVAudioPlayer_blockSupport)
-(id)initWithContentsOfURL:(NSURL *)pathURL error:(NSError **)error onCompletion:(AVPlaybackCompleteBlock )block {
self = [[AVAudioPlayer alloc] initWithContentsOfURL:pathURL error:error];
self.block = block;
return self;
}
-(void)setBlock:(AVPlaybackCompleteBlock)block {
self.block = block;
}
-(AVPlaybackCompleteBlock)block {
return self.block;
}
-(void) executeBlock {
if (self.block != NULL) {
self.block();
}
}
#end
after doing this, i thought i should be able to create a new audioplayer like this:
player = [[AVAudioPlayer alloc] initWithContentsOfURL:pathURL error:&error onCompletion:block];
this appears to be working.
now in the delegate will try to execute the block attached.
if (localPlayer.block) {
[localPlayer executeBlock];
}
unfortunately when i try to run the code, it appears to be looping infinitely. I wanted to use synthesize instead, but thats not for category use...
If i dont implement that Method im stuck with '-[AVAudioPlayer setBlock:]: unrecognized selector sent to instance which makes sense, since there is no method with that name.
i found this Block references as instance vars in Objective-C so i thought i should be able to attach the additional property(my Block) to the AudioPlayer.

Answer 1

I figured it out, i needed to use
objc_setAssociatedObject(self, &defaultHashKey, blocked, OBJC_ASSOCIATION_COPY_NONATOMIC);
to store and access the property. maybe thats what jere meant with, i have tot ake care of the memory management myself.
-(void)setBlock:(AVPlaybackCompleteBlock)blocked {
objc_setAssociatedObject(self, &defaultHashKey, blocked, OBJC_ASSOCIATION_COPY_NONATOMIC);
}
-(AVPlaybackCompleteBlock)block {
return objc_getAssociatedObject(self, &defaultHashKey) ;
}