NSURLSessionDataTask and handler block

Question

I'm developing a library that gets json data from a server, and I'm using NSURLSessionDataTask . In order to test my library I created a new project that calls this library method.

typedef void (^CompletionBlock)();
// More stuff...
- (void)downloadAllPodcastsMetadataWithCompletionHandler:(CompletionBlock)block{

   NSURL *url = [NSURL URLWithString:@"MyServerURL"];

   NSURLSessionDataTask *dataTask = [self.session dataTaskWithURL:url completionHandler:^(NSData *data, NSURLResponse *response, NSError *error) {
     // Connection and response handling stuff...
     // When my data is saved, executes the block parameter

     dispatch_async(dispatch_get_main_queue(), ^{
        block();
     });
   }
   [dataTask resume];
}

EDIT: I forgot to put [dataTask resume] here, but it's in my code. Sorry.

EDIT 2: So, as some of you have said, i changed dispatch_sync with dispatch_async. But the result is the same :(

In my test project i call this method like this.

[UIApplication sharedApplication].networkActivityIndicatorVisible = YES;

[manager downloadAllPodcastsMetadataWithCompletionHandler:^{
    [UIApplication sharedApplication].networkActivityIndicatorVisible = NO;
}];

But the network activity Indicator never shows off. It's like the block parameter never executes.

It's because it executes the NSURLSessionDataTask logic inside a library and then I should use something else instead dispatch_sync ?

I already checked NSURLSessionDataTask not executing the completion handler block and I think I do the same. If it helps, manager is a Singleton . Any thoughts?

Thank you.

Answer 1

You need to start the download with [dataTask resume]; .

Answer 2

You need to add [dataTask resume]; and also add this in completion handler dispatch_async(dispatch_get_main_queue(), ^{ [UIApplication sharedApplication].networkActivityIndicatorVisible = NO; });

Answer 3

I tested some code.

Dispatch_sync won't work.

dispatch_sync(dispatch_get_main_queue(), ^{
    [UIApplication sharedApplication].networkActivityIndicatorVisible = YES;
});

Dispatch_async worked for me. But I had to put the code on veiwWillAppear. Not sure what's going to happen using it inside a block...

dispatch_async(dispatch_get_main_queue(), ^{
    [UIApplication sharedApplication].networkActivityIndicatorVisible = YES;
});

Answer 4

Well, i'm dumb.

There was an error in my previous code i didn't notice, so the completion block war never executing. That is what happens when someone has too much confidence in his code.

Sorry for bothering you.