How can an NSOperationQueue wait for two async operations?

Question

How can I make an NSOperationQueue (or anything else) wait for two async network calls with callbacks? The flow needs to look like this

Block Begins {
    Ne         


        

Answer 1

Do you have to use NSOperation Queue? Here's how you can do it w/ a dispatch group:

dispatch_group_t group = dispatch_group_create();

dispatch_group_enter(group);
[AsyncReq get:^{
    code
    dispatch_group_leave(group); 
} onError:^(NSError *error) {
    code
    dispatch_group_leave(group);
}];


dispatch_group_enter(group);
[AsyncReq get:^{
    code
    dispatch_group_leave(group); 
} onError:^(NSError *error) {
    code
    dispatch_group_leave(group);
}];

dispatch_group_notify(group, dispatch_get_main_queue(), ^{
    NSLog(@"Both operations completed!")
});