Duplicate code is one of the most pungent code smells. A rule that is often used is to re-structure code once it is duplicated in three or more places.
Common duplication problems, and corresponding solutions are:
| 1 | <?php | ||
| 15 | class Handler extends GridFieldBulkActionHandler | ||
| 16 | { | ||
| 17 | private static $allowed_actions = array( | ||
| 18 | 'spam', | ||
| 19 | 'approve', | ||
| 20 | ); | ||
| 21 | |||
| 22 | private static $url_handlers = array( | ||
| 23 | 'spam' => 'spam', | ||
| 24 | 'approve' => 'approve', | ||
| 25 | ); | ||
| 26 | |||
| 27 | /** | ||
| 28 | * @param HTTPRequest $request | ||
| 29 | * @return HTTPResponse | ||
| 30 | */ | ||
| 31 | View Code Duplication | public function spam(HTTPRequest $request) | |
| 49 | |||
| 50 | /** | ||
| 51 | * @param HTTPRequest $request | ||
| 52 | * @return HTTPResponse | ||
| 53 | */ | ||
| 54 | View Code Duplication | public function approve(HTTPRequest $request) | |
| 72 | } | ||
| 73 | 
This check marks private properties in classes that are never used. Those properties can be removed.