Stopping the self.navigationItem.leftBarButtonItem from exiting a view
<p>I want to prevent a view from exiting when the users hits the top left navigation bar button.
If I can do this, I can then ask them if they want to save their work or discard it.</p>

<p>I tried this. But it does not give me the pretty arrow on the left hand side, instead it just gives me a button.</p>

<pre><code>self.navigationItem.leftBarButtonItem = [[UIBarButtonItem alloc] initWithTitle:@"Back" style:UIBarButtonItemStylePlain target:nil action:nil];
</code></pre>

<p>I also tried.</p>

<pre><code>self.navigationItem.backBarButtonItem = [[UIBarButtonItem alloc] initWithTitle:@"Back" style:UIBarButtonItemStylePlain target:nil action:nil];
</code></pre>

<p>But that did not work. 
I did not see a way to override the selector of this either?  Anyone else had any luck.</p>

<p>Cheers, John.</p>
