title: Set a NSTimer in a AsynchronousRequest
body: <p>In my app, I'm getting some data from my server. I need to refresh my data. 
  I'm doing it in background using an asynchronous request.</p>
  
  <p>What I'm doing (and I'm not sure if it is correct and/or recommended to do) is :</p>
  
  <pre><code>-(void)loadData
  {
      //setting url request
      [NSURLConnection sendAsynchronousRequest:urlRequest
                                         queue:[[NSOperationQueue alloc] init]
                             completionHandler:^(NSURLResponse *resp, NSData *data, NSError *err)
      {
          //handling data
          myTimer = [NSTimer scheduledTimerWithTimeInterval:interval 
                                                     target:self 
                                                   selector:@selector(loadData) 
                                                   userInfo:nil repeats:NO];
      }];
  </code></pre>
  
  <p>What I want to do is to wait for my data to be downloaded and handled, and then wait some times before refresh them. But this code does not work as I expect.</p>
  
  <p>Where is my mistake?</p>
  
  <p>Thanks for your help.</p>