title: Wrapping success failure blocks from AFNetworking within a method
body: <p>I need to encapsulate the response from AFNetworking calls within my own method as I'm writing a library. This code gets me close:</p>
  
  <pre><code>MyDevice *devices = [[MyDevice alloc] init];
    [devices getDevices:@"devices.json?user_id=10" success:^(AFHTTPRequestOperation *operation, id responseObject) {
  
      ... can process json object here ...
  
  }
  
   - (void)getDevices:(NSString *)netPath success:(void (^)(AFHTTPRequestOperation *operation, id responseObject))success
      failure:(void (^)(AFHTTPRequestOperation *operation, NSError *error)) failure {
      [[MyApiClient sharedDeviceServiceInstance] getPath:[NSString stringWithFormat:@"%@", netPath]
        parameters:nil success:success  failure:failure];
  }
  </code></pre>
  
  <p>However, I need to process the json object data returned from getPath before returning to getDevices().
  I've tried this:</p>
  
  <pre><code>- (void)getDevices:(NSString *)netPath success:(void (^)(id  myResults))success
          failure:(void (^)(AFHTTPRequestOperation *operation, NSError *error)) failure {
  
    [[MyApiClient sharedDeviceServiceInstance] getPath:[NSString stringWithFormat:@"%@", netPath]
      parameters:nil
      success:^(AFHTTPRequestOperation *operation, id responseObject)
     {
       ... can process json object here ...
     }                           
     failure:^(AFHTTPRequestOperation *operation, NSError *error) {
       ... process errors here ...
     }];
  }
  </code></pre>
  
  <p>But now there is no call back to getDevices().
  So how do I process the json object in getDevices &amp; have the block return on completion?
  Appreciate the help, as I'm new to blocks.</p>