Complex classes like WC_Shipping_Zone 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 WC_Shipping_Zone, and based on these observations, apply Extract Interface, too.
1 | <?php |
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16 | class WC_Shipping_Zone extends WC_Data { |
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17 | |||
18 | protected $id = null; |
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19 | |||
20 | /** |
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21 | * Zone Data |
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22 | * @var array |
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23 | */ |
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24 | protected $data = array( |
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25 | 'zone_name' => '', |
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26 | 'zone_order' => 0, |
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27 | 'zone_locations' => array(), |
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28 | ); |
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29 | |||
30 | /** |
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31 | * True when location data needs to be re-saved |
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32 | * @var bool |
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33 | */ |
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34 | private $locations_changed = false; |
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35 | |||
36 | /** |
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37 | * Constructor for zones |
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38 | * @param int|object $zone Zone ID to load from the DB (optional) or already queried data. |
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39 | */ |
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40 | public function __construct( $zone = null ) { |
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56 | |||
57 | /** |
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58 | * Insert zone into the database |
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59 | */ |
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60 | public function create() { |
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68 | |||
69 | /** |
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70 | * Read zone. |
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71 | * @param int ID to read from DB |
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72 | */ |
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73 | public function read( $id ) { |
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83 | |||
84 | /** |
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85 | * Update zone in the database |
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86 | */ |
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87 | public function update() { |
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97 | |||
98 | /** |
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99 | * Delete a zone. |
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100 | * @since 2.6.0 |
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101 | */ |
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102 | public function delete() { |
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112 | |||
113 | /** |
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114 | * Save zone data to the database. |
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115 | */ |
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116 | public function save() { |
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135 | |||
136 | /** |
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137 | * Set ID. |
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138 | * @param int|null $id |
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139 | */ |
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140 | public function set_id( $id ) { |
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143 | |||
144 | /** |
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145 | * Get ID |
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146 | * @return int|null Null if the zone does not exist. 0 is the default zone. |
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147 | */ |
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148 | public function get_id() { |
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151 | |||
152 | /** |
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153 | * Get zone ID |
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154 | * @return int|null Null if the zone does not exist. 0 is the default zone. |
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155 | */ |
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156 | public function get_zone_id() { |
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159 | |||
160 | /** |
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161 | * Get zone name |
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162 | * @return string |
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163 | */ |
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164 | public function get_zone_name() { |
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167 | |||
168 | /** |
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169 | * Get zone order |
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170 | * @return int |
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171 | */ |
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172 | public function get_zone_order() { |
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175 | |||
176 | /** |
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177 | * Get zone locations |
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178 | * @return array of zone objects |
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179 | */ |
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180 | public function get_zone_locations() { |
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183 | |||
184 | /** |
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185 | * Generate a zone name based on location. |
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186 | * @return string |
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187 | */ |
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188 | protected function generate_zone_name() { |
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197 | |||
198 | /** |
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199 | * Return a text string representing what this zone is for. |
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200 | * @return string |
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201 | */ |
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202 | public function get_formatted_location( $max = 10 ) { |
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244 | |||
245 | /** |
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246 | * Get shipping methods linked to this zone |
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247 | * @param bool Only return enabled methods. |
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248 | * @return array of objects |
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249 | */ |
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250 | public function get_shipping_methods( $enabled_only = false ) { |
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294 | |||
295 | /** |
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296 | * Location type detection |
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297 | * @param object $location |
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298 | * @return boolean |
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299 | */ |
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300 | private function location_is_continent( $location ) { |
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303 | |||
304 | /** |
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305 | * Location type detection |
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306 | * @param object $location |
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307 | * @return boolean |
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308 | */ |
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309 | private function location_is_country( $location ) { |
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312 | |||
313 | /** |
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314 | * Location type detection |
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315 | * @param object $location |
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316 | * @return boolean |
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317 | */ |
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318 | private function location_is_state( $location ) { |
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321 | |||
322 | /** |
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323 | * Location type detection |
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324 | * @param object $location |
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325 | * @return boolean |
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326 | */ |
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327 | private function location_is_postcode( $location ) { |
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330 | |||
331 | /** |
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332 | * Set zone name |
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333 | * @param string $set |
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334 | */ |
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335 | public function set_zone_name( $set ) { |
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338 | |||
339 | /** |
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340 | * Set zone order |
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341 | * @param int $set |
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342 | */ |
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343 | public function set_zone_order( $set ) { |
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346 | |||
347 | /** |
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348 | * Is passed location type valid? |
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349 | * @param string $type |
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350 | * @return boolean |
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351 | */ |
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352 | public function is_valid_location_type( $type ) { |
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355 | |||
356 | /** |
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357 | * Add location (state or postcode) to a zone. |
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358 | * @param string $code |
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359 | * @param string $type state or postcode |
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360 | */ |
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361 | public function add_location( $code, $type ) { |
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374 | |||
375 | /** |
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376 | * Clear all locations for this zone. |
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377 | * @param array|string $types of location to clear |
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378 | */ |
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379 | public function clear_locations( $types = array( 'postcode', 'state', 'country', 'continent' ) ) { |
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390 | |||
391 | /** |
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392 | * Set locations |
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393 | * @param array $locations Array of locations |
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394 | */ |
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395 | public function set_locations( $locations = array() ) { |
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404 | |||
405 | /** |
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406 | * Read location data from the database |
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407 | * @param int $zone_id |
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408 | */ |
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409 | private function read_zone_locations( $zone_id ) { |
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419 | |||
420 | /** |
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421 | * Save locations to the DB. |
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422 | * |
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423 | * This function clears old locations, then re-inserts new if any changes are found. |
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424 | */ |
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425 | private function save_locations() { |
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440 | |||
441 | /** |
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442 | * Add a shipping method to this zone. |
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443 | * @param string $type shipping method type |
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444 | * @return int new instance_id, 0 on failure |
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445 | */ |
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446 | public function add_shipping_method( $type ) { |
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483 | |||
484 | /** |
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485 | * Delete a shipping method from a zone. |
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486 | * @param int $instance_id |
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487 | * @return True on success, false on failure |
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488 | */ |
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489 | public function delete_shipping_method( $instance_id ) { |
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503 | } |
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504 |
In PHP, under loose comparison (like
==
, or!=
, orswitch
conditions), values of different types might be equal.For
integer
values, zero is a special case, in particular the following results might be unexpected: