title: Perform Selector In Background and get the return string
body: <p>I am trying to perform a selector which returns an NSString in the background thread, and the NSString returned will depend on the input object albumlink.</p>
  
  <p>I am performing it in the background, as it takes a while to shorten the URL.</p>
  
  <p>I would really appreciate if you could tell me how I could get the return string.</p>
  
  <p>My code to perform that selector is:</p>
  
  <pre><code>[self performSelectorInBackground:@selector(shortenURL:) withObject:albumlink];
  </code></pre>