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 JsonApiSerializer 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 JsonApiSerializer, and based on these observations, apply Extract Interface, too.
1 | <?php |
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18 | class JsonApiSerializer extends ArraySerializer |
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19 | { |
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20 | /** @var string|null */ |
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21 | protected $baseUrl; |
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22 | |||
23 | /** @var array */ |
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24 | protected $rootObjects; |
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25 | |||
26 | /** |
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27 | * JsonApiSerializer constructor. |
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28 | * |
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29 | * @param string $baseUrl |
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30 | */ |
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31 | 37 | public function __construct(string $baseUrl = null) |
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36 | |||
37 | /** |
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38 | * Serialize a collection. |
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39 | * |
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40 | * @param string $resourceKey |
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41 | * @param array $data |
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42 | * |
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43 | * @return array |
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44 | */ |
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45 | 24 | public function collection($resourceKey, array $data): array |
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55 | |||
56 | /** |
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57 | * Serialize an item. |
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58 | * |
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59 | * @param string $resourceKey |
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60 | * @param array $data |
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61 | * |
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62 | * @return array |
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63 | */ |
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64 | 37 | public function item($resourceKey, array $data): array |
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104 | |||
105 | /** |
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106 | * Serialize the paginator. |
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107 | * |
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108 | * @param PaginatorInterface $paginator |
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109 | * |
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110 | * @return array |
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111 | */ |
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112 | 3 | public function paginator(PaginatorInterface $paginator): array |
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142 | |||
143 | /** |
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144 | * Serialize the meta. |
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145 | * |
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146 | * @param array $meta |
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147 | * |
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148 | * @return array |
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149 | */ |
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150 | 36 | public function meta(array $meta): array |
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167 | |||
168 | /** |
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169 | * Serialize the meta. |
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170 | * |
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171 | * @param array $meta |
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172 | * |
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173 | * @return array |
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174 | */ |
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175 | 2 | public function null(): array |
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181 | |||
182 | /** |
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183 | * Serialize the included data. |
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184 | * |
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185 | * @param ResourceInterface $resource |
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186 | * @param array $data |
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187 | * |
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188 | * @return array |
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189 | */ |
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190 | 36 | public function includedData(ResourceInterface $resource, array $data): array |
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207 | |||
208 | /** |
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209 | * Indicates if includes should be side-loaded. |
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210 | * |
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211 | * @return bool |
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212 | */ |
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213 | 37 | public function sideloadIncludes(): bool |
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217 | |||
218 | /** |
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219 | * @param array $data |
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220 | * @param array $includedData |
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221 | * |
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222 | * @return array |
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223 | */ |
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224 | 36 | public function injectData($data, $includedData): array |
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234 | |||
235 | /** |
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236 | * Hook to manipulate the final sideloaded includes. |
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237 | * The JSON API specification does not allow the root object to be included |
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238 | * into the sideloaded `included`-array. We have to make sure it is |
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239 | * filtered out, in case some object links to the root object in a |
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240 | * relationship. |
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241 | * |
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242 | * @param array $includedData |
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243 | * @param array $data |
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244 | * |
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245 | * @return array |
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246 | */ |
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247 | 36 | public function filterIncludes($includedData, $data): array |
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264 | |||
265 | /** |
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266 | * Get the mandatory fields for the serializer |
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267 | * |
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268 | * @return array |
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269 | */ |
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270 | 4 | public function getMandatoryFields() : array |
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274 | |||
275 | /** |
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276 | * Filter function to delete root objects from array. |
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277 | * |
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278 | * @param array $object |
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279 | * |
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280 | * @return bool |
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281 | */ |
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282 | 18 | protected function filterRootObject($object): bool |
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286 | |||
287 | /** |
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288 | * Set the root objects of the JSON API tree. |
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289 | * |
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290 | * @param array $objects |
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291 | */ |
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292 | 18 | protected function setRootObjects(array $objects = []): void |
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298 | |||
299 | /** |
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300 | * Determines whether an object is a root object of the JSON API tree. |
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301 | * |
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302 | * @param array $object |
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303 | * |
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304 | * @return bool |
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305 | */ |
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306 | 18 | protected function isRootObject($object): bool |
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311 | |||
312 | /** |
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313 | * @param array|null $data |
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314 | * |
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315 | * @return bool |
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316 | */ |
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317 | 29 | View Code Duplication | protected function isCollection($data): bool |
326 | |||
327 | /** |
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328 | * @param array|null $data |
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329 | * |
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330 | * @return bool |
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331 | */ |
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332 | 22 | View Code Duplication | protected function isNull($data): bool |
340 | |||
341 | /** |
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342 | * @param array|null $data |
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343 | * |
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344 | * @return bool |
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345 | */ |
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346 | 21 | View Code Duplication | protected function isEmpty($data): bool |
354 | |||
355 | /** |
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356 | * @param array $data |
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357 | * @param array $relationships |
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358 | * |
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359 | * @return array |
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360 | */ |
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361 | 22 | protected function fillRelationships($data, $relationships): array |
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375 | |||
376 | /** |
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377 | * @param array $includedData |
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378 | * |
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379 | * @return array |
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380 | */ |
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381 | 36 | protected function parseRelationships($includedData): array |
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396 | |||
397 | /** |
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398 | * @param array $data |
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399 | * |
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400 | * @return integer |
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401 | */ |
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402 | 37 | protected function getIdFromData(array $data): int |
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411 | |||
412 | /** |
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413 | * Keep all sideloaded inclusion data on the top level. |
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414 | * |
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415 | * @param array $data |
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416 | * |
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417 | * @return array |
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418 | */ |
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419 | 36 | protected function pullOutNestedIncludedData(array $data): array |
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434 | |||
435 | /** |
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436 | * Whether or not the serializer should include `links` for resource objects. |
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437 | * |
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438 | * @return bool |
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439 | */ |
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440 | 36 | protected function shouldIncludeLinks(): bool |
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444 | |||
445 | /** |
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446 | * Check if the objects are part of a collection or not |
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447 | * |
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448 | * @param array $includeObject |
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449 | * |
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450 | * @return array |
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451 | */ |
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452 | 20 | private function createIncludeObjects($includeObject): array |
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464 | |||
465 | /** |
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466 | * Sets the RootObjects, either as collection or not. |
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467 | * |
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468 | * @param array $data |
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469 | */ |
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470 | 18 | private function createRootObjects(array $data): void |
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478 | |||
479 | /** |
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480 | * Loops over the relationships of the provided data and formats it |
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481 | * |
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482 | * @param array $data |
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483 | * @param array $relationship |
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484 | * @param string $key |
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485 | * |
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486 | * @return array |
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487 | */ |
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488 | 9 | private function fillRelationshipAsCollection($data, $relationship, $key): array |
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496 | |||
497 | |||
498 | /** |
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499 | * @param array $data |
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500 | * @param array $relationship |
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501 | * @param string $key |
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502 | * |
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503 | * @return array |
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504 | */ |
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505 | 15 | private function fillRelationshipAsSingleResource($data, $relationship, $key): array |
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511 | |||
512 | /** |
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513 | * @param string $includeKey |
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514 | * @param array $relationships |
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515 | * @param array $includeObject |
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516 | * @param string $key |
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517 | * |
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518 | * @return array |
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519 | */ |
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520 | 22 | private function buildRelationships(string $includeKey, array $relationships, array $includeObject, string $key): array |
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546 | |||
547 | /** |
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548 | * @param string $includeKey |
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549 | * @param array $relationships |
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550 | * |
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551 | * @return array |
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552 | */ |
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553 | 22 | private function addIncludeKeyToRelationsIfNotSet(string $includeKey, array $relationships): array |
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562 | |||
563 | /** |
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564 | * @param array $includeObject |
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565 | * @param array $relationship |
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566 | * |
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567 | * @return array |
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568 | */ |
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569 | 11 | private function addIncludedDataToRelationship(array $includeObject, array $relationship) : array |
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580 | |||
581 | /** |
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582 | * {@inheritdoc} |
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583 | */ |
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584 | 35 | public function injectAvailableIncludeData($data, $availableIncludes): array |
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605 | |||
606 | |||
607 | /** |
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608 | * Adds links for all available includes to a single resource. |
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609 | * |
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610 | * @param array $resource The resource to add relationship links to |
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611 | * @param string $relationshipKey The resource key of the relationship |
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612 | */ |
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613 | 11 | private function addRelationshipLinks(array $resource, string $relationshipKey): array |
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631 | |||
632 | /** |
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633 | * @param $includeObjects |
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634 | * @param $linkedIds |
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635 | * @param $serializedData |
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636 | * |
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637 | * @return array |
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638 | */ |
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639 | 20 | private function serializeIncludedObjectsWithCacheKey(array $includeObjects, array $linkedIds, array $serializedData): array |
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652 | |||
653 | /** |
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654 | * @param array $resource |
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655 | * |
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656 | * @return bool |
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657 | */ |
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658 | 36 | private function areResourceLinksSet(array $resource): bool |
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662 | |||
663 | /** |
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664 | * @param array $resource |
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665 | * |
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666 | * @return bool |
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667 | */ |
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668 | 36 | private function isResourceMetaSet(array $resource): bool |
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672 | |||
673 | /** |
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674 | * @param array $resource |
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675 | * |
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676 | * @return bool |
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677 | */ |
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678 | 36 | private function isDataAttributesEmpty(array $resource) : bool |
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682 | } |
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683 |
This check looks for PHPDoc comments describing methods or function parameters that do not exist on the corresponding method or function.
Consider the following example. The parameter
$italy
is not defined by the methodfinale(...)
.The most likely cause is that the parameter was removed, but the annotation was not.