iOS completion block

iOS_completion_block

//define before implementation
typedef void(^myCompletion)(BOOL);

//method todo after implementation
-(void) myMethod:(myCompletion) compblock{
    //do stuff
    for (int i = 0; i < 100; i++) {
        NSLog(@"i :: %d", i);
    }
    
    compblock(YES);
}

//caller of the method, knows when complete
    [self myMethod:^(BOOL finished) {
        if(finished){
            NSLog(@"success");
        }
    }];