iOS: Grouping asyn tasks / Grouping server calls

Objective C

dispatch_group_t group = dispatch_group_create();

    

    dispatch_group_enter(group);

    [self _someMethodWithCallback::^() {

        

        NSLog(@"Finished 1");

        dispatch_group_leave(group);

    }];

    dispatch_group_enter(group);

     [self _anotherMethodWithCallback::^() {

        

        NSLog(@"Finished 2");

        dispatch_group_leave(group);

    }];

    

    dispatch_group_notify(group,dispatch_get_global_queue(DISPATCH_QUEUE_PRIORITY_HIGH, 0), ^ {

        

        NSLog(@"Finished all");

    });

Swift

   let group: DispatchGroup = DispatchGroup()
   
   // For every endpoint call
   group.enter()
   someMethodWithCallback(onCompletion: {
                group.leave()
                }, onError: { (error) in
                    group.leave()
            })


    …

   group.notify(queue: DispatchQueue.main) {
            onCompletion()
        }