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:
Complex classes like Comments often do a lot of different things. To break such a class down, we need to identify a cohesive component within that class. A common approach to find such a component is to look for fields/methods that share the same prefixes, or suffixes. You can also have a look at the cohesion graph to spot any un-connected, or weakly-connected components.
Once you have determined the fields that belong together, you can apply the Extract Class refactoring. If the component makes sense as a sub-class, Extract Subclass is also a candidate, and is often faster.
While breaking up the class, it is a good idea to analyze how other classes use Comments, and based on these observations, apply Extract Interface, too.
1 | <?php |
||
16 | class Comments extends Module { |
||
17 | /** |
||
18 | * Sync module name. |
||
19 | * |
||
20 | * @access public |
||
21 | * |
||
22 | * @return string |
||
23 | */ |
||
24 | public function name() { |
||
27 | |||
28 | /** |
||
29 | * The id field in the database. |
||
30 | * |
||
31 | * @access public |
||
32 | * |
||
33 | * @return string |
||
34 | */ |
||
35 | public function id_field() { |
||
38 | |||
39 | /** |
||
40 | * The table in the database. |
||
41 | * |
||
42 | * @access public |
||
43 | * |
||
44 | * @return string |
||
45 | */ |
||
46 | public function table_name() { |
||
49 | |||
50 | /** |
||
51 | * Retrieve a comment by its ID. |
||
52 | * |
||
53 | * @access public |
||
54 | * |
||
55 | * @param string $object_type Type of the sync object. |
||
56 | * @param int $id ID of the sync object. |
||
57 | * @return \WP_Comment|bool Filtered \WP_Comment object, or false if the object is not a comment. |
||
58 | */ |
||
59 | public function get_object_by_id( $object_type, $id ) { |
||
70 | |||
71 | /** |
||
72 | * Initialize comments action listeners. |
||
73 | * Also responsible for initializing comment meta listeners. |
||
74 | * |
||
75 | * @access public |
||
76 | * |
||
77 | * @param callable $callable Action handler callable. |
||
78 | */ |
||
79 | public function init_listeners( $callable ) { |
||
125 | |||
126 | /** |
||
127 | * Handler for any comment content updates. |
||
128 | * |
||
129 | * @access public |
||
130 | * |
||
131 | * @param array $new_comment The new, processed comment data. |
||
132 | * @param array $old_comment The old, unslashed comment data. |
||
133 | * @param array $new_comment_with_slashes The new, raw comment data. |
||
134 | * @return array The new, processed comment data. |
||
135 | */ |
||
136 | public function handle_comment_contents_modification( $new_comment, $old_comment, $new_comment_with_slashes ) { |
||
164 | |||
165 | /** |
||
166 | * Initialize comments action listeners for full sync. |
||
167 | * |
||
168 | * @access public |
||
169 | * |
||
170 | * @param callable $callable Action handler callable. |
||
171 | */ |
||
172 | public function init_full_sync_listeners( $callable ) { |
||
175 | |||
176 | /** |
||
177 | * Gets a filtered list of comment types that sync can hook into. |
||
178 | * |
||
179 | * @access public |
||
180 | * |
||
181 | * @return array Defaults to [ '', 'trackback', 'pingback' ]. |
||
182 | */ |
||
183 | public function get_whitelisted_comment_types() { |
||
196 | |||
197 | /** |
||
198 | * Prevents any comment types that are not in the whitelist from being enqueued and sent to WordPress.com. |
||
199 | * |
||
200 | * @param array $args Arguments passed to wp_insert_comment, deleted_comment, spammed_comment, etc. |
||
201 | * |
||
202 | * @return bool or array $args Arguments passed to wp_insert_comment, deleted_comment, spammed_comment, etc. |
||
203 | */ |
||
204 | public function only_allow_white_listed_comment_types( $args ) { |
||
205 | $comment = false; |
||
206 | |||
207 | if ( isset( $args[1] ) ) { |
||
208 | // comment object is available. |
||
209 | $comment = $args[1]; |
||
210 | } elseif ( is_numeric( $args[0] ) ) { |
||
211 | // comment_id is available. |
||
212 | $comment = get_comment( $args[0] ); |
||
213 | } |
||
214 | |||
215 | if ( false !== $comment && ! in_array( $comment->comment_type, $this->get_whitelisted_comment_types(), true ) ) { |
||
216 | return false; |
||
217 | } |
||
218 | |||
219 | return $args; |
||
220 | } |
||
221 | |||
222 | /** |
||
223 | * Filter all blacklisted post types. |
||
224 | * |
||
225 | * @param array $args Hook arguments. |
||
226 | * @return array|false Hook arguments, or false if the post type is a blacklisted one. |
||
227 | */ |
||
228 | public function filter_blacklisted_post_types( $args ) { |
||
238 | |||
239 | /** |
||
240 | * Prevents any comment types that are not in the whitelist from being enqueued and sent to WordPress.com. |
||
241 | * |
||
242 | * @param array $args Arguments passed to wp_{old_status}_to_{new_status}. |
||
243 | * |
||
244 | * @return bool or array $args Arguments passed to wp_{old_status}_to_{new_status} |
||
245 | */ |
||
246 | public function only_allow_white_listed_comment_type_transitions( $args ) { |
||
255 | |||
256 | /** |
||
257 | * Whether a comment type is allowed. |
||
258 | * A comment type is allowed if it's present in the comment type whitelist. |
||
259 | * |
||
260 | * @param int $comment_id ID of the comment. |
||
261 | * @return boolean Whether the comment type is allowed. |
||
262 | */ |
||
263 | public function is_comment_type_allowed( $comment_id ) { |
||
271 | |||
272 | /** |
||
273 | * Initialize the module in the sender. |
||
274 | * |
||
275 | * @access public |
||
276 | */ |
||
277 | public function init_before_send() { |
||
296 | |||
297 | /** |
||
298 | * Enqueue the comments actions for full sync. |
||
299 | * |
||
300 | * @access public |
||
301 | * |
||
302 | * @param array $config Full sync configuration for this sync module. |
||
303 | * @param int $max_items_to_enqueue Maximum number of items to enqueue. |
||
304 | * @param boolean $state True if full sync has finished enqueueing this module, false otherwise. |
||
305 | * @return array Number of actions enqueued, and next module state. |
||
306 | */ |
||
307 | public function enqueue_full_sync_actions( $config, $max_items_to_enqueue, $state ) { |
||
311 | |||
312 | /** |
||
313 | * Retrieve an estimated number of actions that will be enqueued. |
||
314 | * |
||
315 | * @access public |
||
316 | * |
||
317 | * @param array $config Full sync configuration for this sync module. |
||
318 | * @return int Number of items yet to be enqueued. |
||
319 | */ |
||
320 | View Code Duplication | public function estimate_full_sync_actions( $config ) { |
|
336 | |||
337 | /** |
||
338 | * Retrieve the WHERE SQL clause based on the module config. |
||
339 | * |
||
340 | * @access public |
||
341 | * |
||
342 | * @param array $config Full sync configuration for this sync module. |
||
343 | * @return string WHERE SQL clause, or `null` if no comments are specified in the module config. |
||
344 | */ |
||
345 | public function get_where_sql( $config ) { |
||
352 | |||
353 | /** |
||
354 | * Retrieve the actions that will be sent for this module during a full sync. |
||
355 | * |
||
356 | * @access public |
||
357 | * |
||
358 | * @return array Full sync actions of this module. |
||
359 | */ |
||
360 | public function get_full_sync_actions() { |
||
363 | |||
364 | /** |
||
365 | * Count all the actions that are going to be sent. |
||
366 | * |
||
367 | * @access public |
||
368 | * |
||
369 | * @param array $action_names Names of all the actions that will be sent. |
||
370 | * @return int Number of actions. |
||
371 | */ |
||
372 | public function count_full_sync_actions( $action_names ) { |
||
375 | |||
376 | /** |
||
377 | * Expand the comment status change before the data is serialized and sent to the server. |
||
378 | * |
||
379 | * @access public |
||
380 | * @todo This is not used currently - let's implement it. |
||
381 | * |
||
382 | * @param array $args The hook parameters. |
||
383 | * @return array The expanded hook parameters. |
||
384 | */ |
||
385 | public function expand_wp_comment_status_change( $args ) { |
||
388 | |||
389 | /** |
||
390 | * Expand the comment creation before the data is serialized and sent to the server. |
||
391 | * |
||
392 | * @access public |
||
393 | * |
||
394 | * @param array $args The hook parameters. |
||
395 | * @return array The expanded hook parameters. |
||
396 | */ |
||
397 | public function expand_wp_insert_comment( $args ) { |
||
400 | |||
401 | /** |
||
402 | * Filter a comment object to the fields we need. |
||
403 | * |
||
404 | * @access public |
||
405 | * |
||
406 | * @param \WP_Comment $comment The unfiltered comment object. |
||
407 | * @return \WP_Comment Filtered comment object. |
||
408 | */ |
||
409 | public function filter_comment( $comment ) { |
||
435 | |||
436 | /** |
||
437 | * Whether a certain comment meta key is whitelisted for sync. |
||
438 | * |
||
439 | * @access public |
||
440 | * |
||
441 | * @param string $meta_key Comment meta key. |
||
442 | * @return boolean Whether the meta key is whitelisted. |
||
443 | */ |
||
444 | public function is_whitelisted_comment_meta( $meta_key ) { |
||
447 | |||
448 | /** |
||
449 | * Handler for filtering out non-whitelisted comment meta. |
||
450 | * |
||
451 | * @access public |
||
452 | * |
||
453 | * @param array $args Hook args. |
||
454 | * @return array|boolean False if not whitelisted, the original hook args otherwise. |
||
455 | */ |
||
456 | public function filter_meta( $args ) { |
||
463 | |||
464 | /** |
||
465 | * Expand the comment IDs to comment objects and meta before being serialized and sent to the server. |
||
466 | * |
||
467 | * @access public |
||
468 | * |
||
469 | * @param array $args The hook parameters. |
||
470 | * @return array The expanded hook parameters. |
||
471 | */ |
||
472 | public function expand_comment_ids( $args ) { |
||
489 | } |
||
490 |