This is a really lame way to get the WordPress Post ID when on the administration screen.

get-admin-post-id.php

<?php

  // ...
  
  // This should NOT be this difficult ... but at the moment it's what we have.
	private function _get_admin_post_id()
	{
		return absint(isset($_GET['post']) ? $_GET['post'] : (isset($_POST['post_ID']) ? $_POST['post_ID'] : 0));
	}