title: How to make UINavigationItem backBarButtonItem rectangular?
body: <p>How can set <code>self.navigationItem.backBarButtonItem</code> of my <code>RootViewController</code>, so that the back button is rectangular instead of having a back arrow? I want to do this because I'm using a custom <code>backBarButtonItem</code> with an image of a grid of four squares (like the nine-square-gird image that the Facebook iPhone app uses for its home button).</p>
  
  <p>Currently, in <code>-[RootViewController initWitNibName:bundle:]</code>, I do:</p>
  
  <pre><code>self.navigationItem.backBarButtonItem =
  [[UIBarButtonItem alloc] initWithImage:[UIImage imageNamed:@"go-home.png"]
                                   style:UIBarButtonItemStylePlain
                                  target:nil action:NULL];
  </code></pre>
  
  <p><em>Note: This does not cause a memory leak as I'm using ARC.</em></p>
  
  <p>But, this makes the button have a left arrow. Is there a simple fix to make the button rectangular on all sides?</p>
  
  <p>I know I could set the <code>leftBarButtonItem</code> for all of the view controllers that can get pushed from the <code>RootViewController</code>, but there are like five different options, so that'd be a lot of repetition. I guess I could make a method, e.g., <code>+[Utils homeBarButtonItem]</code>, that creates the button above and then call <code>self.navigationItem.leftBarButtonItem = [Utils homeBarButtonItem];</code> in each of the five view controllers' <code>-viewDidLoad</code> methods, but I'm wondering if there's a simple fix I'm missing.</p>