Question

I have a function using AFJSONRequestOperation, and I wish to return the result only after success. Could you point me in the right direction? I’m still a bit clueless with blocks and AFNetworking specifically.

-(id)someFunction{
    __block id data;

    AFJSONRequestOperation *operation = [AFJSONRequestOperation JSONRequestOperationWithRequest:request
        success:^(NSURLRequest *request, NSHTTPURLResponse *response, id json){
            data = json;
            return data; // won't work
        }
        failure:^(NSURLRequest *request, NSHTTPURLResponse *response, NSError *error){

        }];



    NSOperationQueue *queue = [[NSOperationQueue alloc] init];
    [queue addOperation: operation];

    return data; // will return nil since the block doesn't "lock" the app.
}

Answer 1

To block the execution of the main thread until the operation completes, you could do [operation waitUntilFinished] after it’s added to the operation queue. In this case, you wouldn’t need the return in the block; setting the __block variable would be enough.

That said, I’d strongly discourage forcing asynchronous operations to synchronous methods. It’s tricky to get your head around sometimes, but if there’s any way you could structure this to be asynchronous, that would almost certainly be the way to go.