title: How to use stringWithContentsOfURL:encoding:error:?
body: <p>I am trying to use initWithContentsOfURL:encoding:error: like this :</p>
  
  <p><pre><code>
  NSURL *url = [[NSURL alloc] initWithString:@"http://my_url.com/my_file.xml"];
  NSError *error = nil;
  NSString *my_string = [[NSString alloc] initWithContentsOfURL:url
  encoding:NSUTF8StringEncoding
  error:&amp;error];
  </pre></code></p>
  
  <p>I get a empty my_string variable.</p>
  
  <p>I tried the initWithContentsOfURL: method (which is deprecated in iOS 2.0) and I get the content of my page. But I still need to specify a encoding language.</p>
  
  <p>What's wrong ?</p>
  
  <p>Thanks :)</p>