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 Give_Logging 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 Give_Logging, and based on these observations, apply Extract Interface, too.
1 | <?php |
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24 | class Give_Logging { |
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25 | /** |
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26 | * Logs data operation handler object. |
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27 | * |
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28 | * @since 2.0 |
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29 | * @access private |
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30 | * @var Give_DB_Logs |
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31 | */ |
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32 | public $log_db; |
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33 | |||
34 | /** |
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35 | * Log meta data operation handler object. |
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36 | * |
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37 | * @since 2.0 |
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38 | * @access private |
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39 | * @var Give_DB_Log_Meta |
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40 | */ |
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41 | public $logmeta_db; |
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42 | |||
43 | /** |
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44 | * Class Constructor |
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45 | * |
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46 | * Set up the Give Logging Class. |
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47 | * |
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48 | * @since 1.0 |
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49 | * @access public |
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50 | */ |
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51 | public function __construct() { |
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79 | |||
80 | |||
81 | /** |
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82 | * Log Post Type |
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83 | * |
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84 | * Registers the 'give_log' Post Type. |
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85 | * |
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86 | * @since 1.0 |
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87 | * @access public |
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88 | * |
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89 | * @return void |
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90 | */ |
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91 | public function register_post_type() { |
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110 | |||
111 | /** |
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112 | * Log Type Taxonomy |
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113 | * |
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114 | * Registers the "Log Type" taxonomy. Used to determine the type of log entry. |
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115 | * |
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116 | * @since 1.0 |
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117 | * @access public |
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118 | * |
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119 | * @return void |
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120 | */ |
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121 | public function register_taxonomy() { |
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126 | |||
127 | /** |
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128 | * Log Types |
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129 | * |
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130 | * Sets up the default log types and allows for new ones to be created. |
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131 | * |
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132 | * @since 1.0 |
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133 | * @access public |
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134 | * |
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135 | * @return array $terms |
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136 | */ |
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137 | public function log_types() { |
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147 | |||
148 | /** |
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149 | * Check if a log type is valid |
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150 | * |
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151 | * Checks to see if the specified type is in the registered list of types. |
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152 | * |
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153 | * @since 1.0 |
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154 | * @access public |
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155 | * |
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156 | * @param string $type Log type. |
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157 | * |
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158 | * @return bool Whether log type is valid. |
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159 | */ |
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160 | public function valid_type( $type ) { |
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163 | |||
164 | /** |
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165 | * Create new log entry |
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166 | * |
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167 | * This is just a simple and fast way to log something. Use $this->insert_log() |
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168 | * if you need to store custom meta data. |
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169 | * |
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170 | * @since 1.0 |
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171 | * @access public |
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172 | * |
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173 | * @param string $title Log entry title. Default is empty. |
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174 | * @param string $message Log entry message. Default is empty. |
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175 | * @param int $parent Log entry parent. Default is 0. |
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176 | * @param string $type Log type. Default is empty string. |
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177 | * |
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178 | * @return int Log ID. |
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179 | */ |
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180 | public function add( $title = '', $message = '', $parent = 0, $type = '' ) { |
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190 | |||
191 | /** |
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192 | * Get Logs |
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193 | * |
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194 | * Retrieves log items for a particular object ID. |
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195 | * |
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196 | * @since 1.0 |
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197 | * @access public |
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198 | * |
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199 | * @param int $object_id Log object ID. Default is 0. |
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200 | * @param string $type Log type. Default is empty string. |
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201 | * @param int $paged Page number Default is null. |
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202 | * |
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203 | * @return array An array of the connected logs. |
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204 | */ |
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205 | public function get_logs( $object_id = 0, $type = '', $paged = null ) { |
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212 | |||
213 | /** |
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214 | * Stores a log entry |
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215 | * |
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216 | * @since 1.0 |
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217 | * @access public |
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218 | * |
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219 | * @param array $log_data Log entry data. |
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220 | * @param array $log_meta Log entry meta. |
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221 | * |
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222 | * @return int The ID of the newly created log item. |
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223 | */ |
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224 | public function insert_log( $log_data = array(), $log_meta = array() ) { |
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268 | |||
269 | /** |
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270 | * Update and existing log item |
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271 | * |
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272 | * @since 1.0 |
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273 | * @access public |
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274 | * |
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275 | * @param array $log_data Log entry data. |
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276 | * @param array $log_meta Log entry meta. |
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277 | * |
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278 | * @return bool|null True if successful, false otherwise. |
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279 | */ |
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280 | public function update_log( $log_data = array(), $log_meta = array() ) { |
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339 | |||
340 | /** |
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341 | * Retrieve all connected logs |
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342 | * |
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343 | * Used for retrieving logs related to particular items, such as a specific donation. |
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344 | * For new table params check: Give_DB_Logs::get_column_defaults and Give_DB_Logs::get_sql#L262 |
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345 | * |
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346 | * @since 1.0 |
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347 | * @since 2.0 Added new table logic. |
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348 | * @access public |
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349 | * |
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350 | * @param array $args Query arguments. |
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351 | * |
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352 | * @return array|false Array if logs were found, false otherwise. |
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353 | */ |
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354 | public function get_connected_logs( $args = array() ) { |
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379 | |||
380 | /** |
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381 | * Retrieve Log Count |
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382 | * |
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383 | * Retrieves number of log entries connected to particular object ID. |
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384 | * |
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385 | * @since 1.0 |
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386 | * @access public |
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387 | * |
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388 | * @param int $object_id Log object ID. Default is 0. |
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389 | * @param string $type Log type. Default is empty string. |
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390 | * @param array $meta_query Log meta query. Default is null. |
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391 | * @param array $date_query Log data query. Default is null. |
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392 | * |
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393 | * @return int Log count. |
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394 | */ |
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395 | public function get_log_count( $object_id = 0, $type = '', $meta_query = null, $date_query = null ) { |
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434 | |||
435 | /** |
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436 | * Delete Logs |
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437 | * |
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438 | * Remove log entries connected to particular object ID. |
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439 | * |
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440 | * @since 1.0 |
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441 | * @access public |
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442 | * |
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443 | * @param int $object_id Log object ID. Default is 0. |
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444 | * @param string $type Log type. Default is empty string. |
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445 | * @param array $meta_query Log meta query. Default is null. |
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446 | * |
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447 | * @return void |
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448 | */ |
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449 | public function delete_logs( $object_id = 0, $type = '', $meta_query = null ) { |
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493 | |||
494 | /** |
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495 | * Setup cron to delete log cache in background. |
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496 | * |
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497 | * @since 1.7 |
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498 | * @access public |
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499 | * |
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500 | * @param int $post_id |
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501 | */ |
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502 | public function background_process_delete_cache( $post_id ) { |
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506 | |||
507 | /** |
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508 | * Delete all logging cache when form, log or payment updates |
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509 | * |
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510 | * @since 1.7 |
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511 | * @access public |
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512 | * |
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513 | * @return bool |
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514 | */ |
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515 | public function delete_cache() { |
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529 | |||
530 | /** |
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531 | * Validate query params. |
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532 | * |
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533 | * @since 2.0 |
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534 | * @access private |
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535 | * |
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536 | * @param array $log_query |
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537 | * @param array $log_meta |
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538 | */ |
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539 | private function bc_200_validate_params( &$log_query, &$log_meta = array() ) { |
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631 | |||
632 | /** |
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633 | * Set new log properties. |
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634 | * |
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635 | * @since 2.0 |
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636 | * @access private |
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637 | * |
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638 | * @param array $logs |
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639 | */ |
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640 | private function bc_200_add_new_properties( &$logs ) { |
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683 | |||
684 | /** |
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685 | * Change log parent to payment if set to form. |
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686 | * |
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687 | * @since 2.0 |
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688 | * @access public |
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689 | * |
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690 | * @param mixed $check |
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691 | * @param int $log_id |
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692 | * @param array $meta_key |
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693 | * @param array $meta_value |
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694 | * |
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695 | * @return mixed |
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696 | */ |
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697 | public function bc_200_set_payment_as_log_parent( $check, $log_id, $meta_key, $meta_value ) { |
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743 | } |
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744 |
This check looks for variable assignements that are either overwritten by other assignments or where the variable is not used subsequently.
Both the
$myVar
assignment in line 1 and the$higher
assignment in line 2 are dead. The first because$myVar
is never used and the second because$higher
is always overwritten for every possible time line.