title: loading images from a background thread using blocks
body: <p>I have the following method, which basically calls a request to load an array of NSData of images in the background thread:</p>
  
  <pre><code>[query findObjectsInBackgroundWithBlock:^(NSArray * objects, NSError * error){
  
  }];
  </code></pre>
  
  <p>In this case objects is an array of the NSData. The issue is that if I have 100 images to load (100 elements in the array). This means that the user will have to wait for quite some time to see any image showing up in a UITableView. What I want to do is for them to see an image once it is available/loaded.. do I have to then change the code so that it does 100 background threads to load the image?</p>