Question

Can I store ^block in a dictionary or an array?

I need to listen to a server notification which I need to provide a block to handle the notification, and in my project several view controllers all want to hear the notification, so I made a generic notification manager, which has its own block for handling server notification and it has an array of delegates, so in the manager’s block:

- (^)(NSString *message){
    for (delegate in allDelegates)
    {
        delegate.handlerBlock(message);
    }
}

but can I store blocks in a collection?

Answer 1

You can store object into collection. But take care of the scope: Copy them when they will be kept out of a function scope. This is your case since you are storing them in a array.

[NSArray arrayWithObject: 
[[^{ NSLog(@"block 1"); } copy] autorelease],
[[^{ NSLog(@"block 2"); } copy] autorelease], nil]

On ARC, you still need to tell it you absolutely needs to copy your block. It should release the block when the array is freed.

  [NSArray arrayWithObject: 
    [^{ NSLog(@"block 1"); } copy],
    [^{ NSLog(@"block 2"); } copy], nil]