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 | protected $baseUrl; |
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21 | protected $rootObjects; |
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22 | |||
23 | /** |
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24 | * JsonApiSerializer constructor. |
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25 | * |
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26 | * @param string $baseUrl |
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27 | */ |
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28 | 29 | public function __construct($baseUrl = null) |
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33 | |||
34 | /** |
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35 | * Serialize a collection. |
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36 | * |
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37 | * @param string $resourceKey |
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38 | * @param array $data |
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39 | * |
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40 | * @return array |
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41 | */ |
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42 | 21 | public function collection($resourceKey, array $data) |
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52 | |||
53 | /** |
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54 | * Serialize an item. |
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55 | * |
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56 | * @param string $resourceKey |
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57 | * @param array $data |
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58 | * |
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59 | * @return array |
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60 | */ |
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61 | 29 | public function item($resourceKey, array $data) |
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83 | |||
84 | /** |
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85 | * Serialize the paginator. |
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86 | * |
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87 | * @param PaginatorInterface $paginator |
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88 | * |
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89 | * @return array |
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90 | */ |
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91 | 3 | public function paginator(PaginatorInterface $paginator) |
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121 | |||
122 | /** |
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123 | * Serialize the meta. |
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124 | * |
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125 | * @param array $meta |
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126 | * |
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127 | * @return array |
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128 | */ |
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129 | 28 | public function meta(array $meta) |
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144 | |||
145 | /** |
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146 | * @return array |
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147 | */ |
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148 | 2 | public function null() |
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154 | |||
155 | /** |
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156 | * Serialize the included data. |
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157 | * |
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158 | * @param ResourceInterface $resource |
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159 | * @param array $data |
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160 | * |
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161 | * @return array |
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162 | */ |
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163 | 28 | public function includedData(ResourceInterface $resource, array $data) |
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189 | |||
190 | /** |
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191 | * Indicates if includes should be side-loaded. |
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192 | * |
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193 | * @return bool |
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194 | */ |
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195 | 29 | public function sideloadIncludes() |
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199 | |||
200 | /** |
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201 | * @param array $data |
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202 | * @param array $includedData |
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203 | * |
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204 | * @return array |
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205 | */ |
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206 | 28 | public function injectData($data, $includedData) |
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216 | |||
217 | /** |
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218 | * Hook to manipulate the final sideloaded includes. |
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219 | * The JSON API specification does not allow the root object to be included |
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220 | * into the sideloaded `included`-array. We have to make sure it is |
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221 | * filtered out, in case some object links to the root object in a |
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222 | * relationship. |
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223 | * |
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224 | * @param array $includedData |
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225 | * @param array $data |
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226 | * |
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227 | * @return array |
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228 | */ |
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229 | 28 | public function filterIncludes($includedData, $data) |
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246 | |||
247 | /** |
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248 | * Get the mandatory fields for the serializer |
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249 | * |
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250 | * @return array |
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251 | */ |
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252 | 4 | public function getMandatoryFields() |
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256 | |||
257 | /** |
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258 | * Filter function to delete root objects from array. |
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259 | * |
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260 | * @param array $object |
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261 | * |
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262 | * @return bool |
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263 | */ |
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264 | 15 | protected function filterRootObject($object) |
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268 | |||
269 | /** |
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270 | * Set the root objects of the JSON API tree. |
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271 | * |
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272 | * @param array $objects |
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273 | */ |
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274 | protected function setRootObjects(array $objects = []) |
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280 | |||
281 | /** |
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282 | * Determines whether an object is a root object of the JSON API tree. |
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283 | * |
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284 | * @param array $object |
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285 | * |
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286 | * @return bool |
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287 | */ |
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288 | 15 | protected function isRootObject($object) |
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293 | |||
294 | /** |
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295 | * @param array $data |
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296 | * |
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297 | * @return bool |
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298 | */ |
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299 | 19 | protected function isCollection($data) |
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304 | |||
305 | /** |
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306 | * @param array $data |
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307 | * |
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308 | * @return bool |
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309 | */ |
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310 | 19 | protected function isNull($data) |
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314 | |||
315 | /** |
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316 | * @param array $data |
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317 | * |
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318 | * @return bool |
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319 | */ |
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320 | 18 | protected function isEmpty($data) |
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324 | |||
325 | /** |
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326 | * @param array $data |
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327 | * @param array $relationships |
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328 | * |
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329 | * @return array |
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330 | */ |
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331 | 19 | protected function fillRelationships($data, $relationships) |
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345 | |||
346 | /** |
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347 | * @param array $includedData |
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348 | * |
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349 | * @return array |
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350 | */ |
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351 | 28 | protected function parseRelationships($includedData) |
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363 | |||
364 | /** |
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365 | * @param array $data |
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366 | * |
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367 | * @return integer |
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368 | */ |
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369 | 29 | protected function getIdFromData(array $data) |
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378 | |||
379 | /** |
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380 | * Keep all sideloaded inclusion data on the top level. |
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381 | * |
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382 | * @param array $data |
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383 | * |
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384 | * @return array |
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385 | */ |
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386 | 28 | protected function pullOutNestedIncludedData(array $data) |
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410 | |||
411 | /** |
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412 | * Whether or not the serializer should include `links` for resource objects. |
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413 | * |
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414 | * @return bool |
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415 | */ |
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416 | 28 | protected function shouldIncludeLinks() |
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420 | |||
421 | /** |
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422 | * Check if the objects are part of a collection or not |
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423 | * |
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424 | * @param $includeObject |
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425 | * |
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426 | * @return array |
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427 | */ |
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428 | 17 | private function createIncludeObjects($includeObject) |
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440 | |||
441 | /** |
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442 | * Sets the RootObjects, either as collection or not. |
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443 | * |
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444 | * @param $data |
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445 | */ |
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446 | 15 | private function createRootObjects($data) |
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454 | |||
455 | |||
456 | /** |
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457 | * Loops over the relationships of the provided data and formats it |
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458 | * |
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459 | * @param $data |
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460 | * @param $relationship |
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461 | * @param $nestedDepth |
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462 | * |
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463 | * @return array |
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464 | */ |
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465 | 7 | private function fillRelationshipAsCollection($data, $relationship, $nestedDepth) |
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473 | |||
474 | |||
475 | /** |
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476 | * @param $data |
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477 | * @param $relationship |
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478 | * @param $key |
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479 | * |
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480 | * @return array |
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481 | */ |
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482 | 14 | private function FillRelationshipAsSingleResource($data, $relationship, $key) |
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498 | |||
499 | /** |
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500 | * @param $includeKey |
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501 | * @param $relationships |
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502 | * @param $includeObject |
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503 | * @param $key |
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504 | * |
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505 | * @return array |
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506 | */ |
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507 | 19 | private function buildRelationships($includeKey, $relationships, $includeObject, $key) |
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534 | |||
535 | /** |
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536 | * @param $includeKey |
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537 | * @param $relationships |
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538 | * |
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539 | * @return array |
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540 | */ |
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541 | 19 | private function addIncludekeyToRelationsIfNotSet($includeKey, $relationships) |
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550 | |||
551 | /** |
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552 | * @param $includeObject |
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553 | * @param $relationship |
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554 | * |
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555 | * @return array |
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556 | */ |
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557 | 10 | private function addIncludedDataToRelationship($includeObject, $relationship) |
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568 | } |
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569 |