Custom completion block for my own method [duplicate]

Question

I have just discovered completion blocks:

 completion:^(BOOL finished){                        }]; 

What do I need to do to have my own method take a completion block?

Answer 1

1) Define your own completion block,

typedef void(^myCompletion)(BOOL); 

2) Create a method which takes your completion block as a parameter,

-(void) myMethod:(myCompletion) compblock{     //do stuff     compblock(YES); } 

3)This is how you use it,

[self myMethod:^(BOOL finished) {     if(finished){         NSLog(@"success");     } }]; 

Answer 2

You define the block as a custom type:

typedef void (^ButtonCompletionBlock)(int buttonIndex); 

Then use it as an argument to a method:

+ (SomeButtonView*)buttonViewWithTitle:(NSString *)title                            cancelAction:(ButtonCompletionBlock)cancelBlock                       completionAction:(ButtonCompletionBlock)completionBlock 

When calling this in code it is just like any other block:

[SomeButtonView buttonViewWithTitle:@"Title"                        cancelAction:^(int buttonIndex) {                              NSLog(@"User cancelled");                    }                       completionAction:^(int buttonIndex) {                              NSLog(@"User tapped index %i", buttonIndex);                    }]; 

If it comes time to trigger the block, simply call completionBlock() (where completionBlock is the name of your local copy of the block).