How to batch request with AFNetworking 2?

Thanks Sendoa for the link to the GitHub issue where Mattt explains why this functionality is not working anymore. There is a clear reason why this isn’t possible with the new NSURLSession structure; Tasks just aren’t operations, so the old way of using dependencies or batches of operations won’t work.

I’ve created this solution using a dispatch_group that makes it possible to batch requests using NSURLSession, here is the (pseudo-)code:

// Create a dispatch group
dispatch_group_t group = dispatch_group_create();

for (int i = 0; i < 10; i++) {
    // Enter the group for each request we create
    dispatch_group_enter(group);

    // Fire the request
    [self GET:@"endpoint.json"
       parameters:nil
          success:^(NSURLSessionDataTask *task, id responseObject) {
                  // Leave the group as soon as the request succeeded
                  dispatch_group_leave(group);
          }
      failure:^(NSURLSessionDataTask *task, NSError *error) {
                  // Leave the group as soon as the request failed
                  dispatch_group_leave(group);
              }];
}

// Here we wait for all the requests to finish
dispatch_group_notify(group, dispatch_get_main_queue(), ^{
    // Do whatever you need to do when all requests are finished
});

I want to look write something that makes this easier to do and discuss with Matt if this is something (when implemented nicely) that could be merged into AFNetworking. In my opinion it would be great to do something like this with the library itself. But I have to check when I have some spare time for that.