title: Detecting when a cell's detail-disclosure button has been clicked (when using a custom cell XIB)
body: <pre><code>if (cell == nil)       // 1
  {                      // 2
     [[NSBundle mainBundle] loadNibNamed:@"TVCell" owner:self options:nil];  // 3
     cell = tvCell;      // 4
     self.tvCell = nil;  // 5
  }                      // 6
  </code></pre>
  
  <p>There's some code from an Apple example of using your own "custom cell XIB" to create cells in a UITableView.</p>
  
  <p>It appears to work... but I think I would do better to actually <em>understand</em> what is being done there.</p>
  
  <ul>
  <li><p>Why isn't the following assigning the value <em>to</em> something?</p>
  
  <pre><code>cell = [[NSBundle mainBundle] loadNibNamed:@"TVCell" owner:self options:nil];
  </code></pre>
  
  <p>(In fact, <code>cell</code> and <code>tvCell</code> aren't being used at all.)</p></li>
  <li><p>Why is line #4 assigning using <code>tvCell</code> when nothing has been put it in at all, yet?</p></li>
  <li><p>Why is line #5 nulling out the <code>tvCell</code> that I need?</p></li>
  <li><p>Why is this line using assign, not retain?</p>
  
  <pre><code>@property (nonatomic, assign) IBOutlet UITableViewCell *tvCell;
  </code></pre></li>
  </ul>
  
  <p>About the only thing I can't get working correctly is when I put a disclosure-button on my custom cell XIB.  Is there a way for me to detect when the user has clicked on it?  (Hopefully, without using 100s of TAGs.)</p>