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