AFNetworking downloading queue

Question

I can't figure out a way of downloading objects in a queue using AFNetworking 2.0.

I have an array of ID's. I want to make a request with the last object from array, when this request is completed, make a second request, third request, and so on.. But if at least one request fails, I need to stop.

while ([dataArray count] > 0) {

    [[APIClient sharedClient] POST:@"/api/my_object.json" parameters:@{@"obj":[dataArray lastObject]} success:^(NSURLSessionDataTask *task, id responseObject) {
        [dataArray removeLastObject];
    } failure:^(NSURLSessionDataTask *task, NSError *error) {
        break;
    }];
}

I Know this is not right, because i get async callbacks. So Maybe anyone could suggest of how to achieve this? Maybe using queues or something like that?

Thanks in advance for any help!

Answer 1

Your solution is to make one request at the time. That means, start a new request only when you get a result from the last one.

Something like this:

-(void) makeNextRequest {
   __typeof__ (self) __weak weakSelf = self;
   [[APIClient sharedClient] POST:@"/api/my_object.json" parameters:@{@"obj":[dataArray lastObject]} success:^(NSURLSessionDataTask *task, id responseObject) {
        [dataArray removeLastObject];
        [weakSelf makeNextRequest];
    } failure:^(NSURLSessionDataTask *task, NSError *error) {

    }];
}