title: Should require_once "some file.php" ; appear anywhere but the top of the file?
body: <p>Is the following example appropriate for PHP's require_once construct?</p>
  
  <pre><code>function foo( $param )
  {
      require_once "my_file.php" ;
      //
      // do something here
  }
  </code></pre>
  
  <p>Or is it more appropriate to only have require_once constructs at the beginning of the file?</p>
  
  <p>Even though the file being included is useful only in the context of the function, is it not better to have includes at the top for readability and maintainability?</p>