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 $rootObjects; |
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22 | |||
23 | 25 | public function __construct($baseUrl = null) |
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24 | { |
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25 | 25 | $this->baseUrl = $baseUrl; |
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26 | 25 | $this->rootObjects = []; |
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27 | 25 | } |
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28 | |||
29 | /** |
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30 | * Serialize a collection. |
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31 | * |
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32 | * @param string $resourceKey |
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33 | * @param array $data |
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34 | * |
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35 | * @return array |
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36 | */ |
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37 | 17 | public function collection($resourceKey, array $data) |
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38 | { |
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39 | 17 | $resources = []; |
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40 | |||
41 | 17 | foreach ($data as $resource) { |
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42 | 16 | $resources[] = $this->item($resourceKey, $resource)['data']; |
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43 | 17 | } |
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44 | |||
45 | 17 | return ['data' => $resources]; |
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46 | } |
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47 | |||
48 | /** |
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49 | * Serialize an item. |
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50 | * |
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51 | * @param string $resourceKey |
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52 | * @param array $data |
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53 | * |
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54 | * @return array |
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55 | */ |
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56 | 25 | public function item($resourceKey, array $data) |
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78 | |||
79 | /** |
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80 | * Serialize the paginator. |
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81 | * |
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82 | * @param PaginatorInterface $paginator |
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83 | * |
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84 | * @return array |
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85 | */ |
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86 | 3 | public function paginator(PaginatorInterface $paginator) |
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87 | { |
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88 | 3 | $currentPage = (int) $paginator->getCurrentPage(); |
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89 | 3 | $lastPage = (int) $paginator->getLastPage(); |
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90 | |||
91 | $pagination = [ |
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92 | 3 | 'total' => (int) $paginator->getTotal(), |
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93 | 3 | 'count' => (int) $paginator->getCount(), |
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94 | 3 | 'per_page' => (int) $paginator->getPerPage(), |
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95 | 3 | 'current_page' => $currentPage, |
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96 | 3 | 'total_pages' => $lastPage, |
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97 | 3 | ]; |
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98 | |||
99 | 3 | $pagination['links'] = []; |
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100 | |||
101 | 3 | $pagination['links']['self'] = $paginator->getUrl($currentPage); |
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102 | 3 | $pagination['links']['first'] = $paginator->getUrl(1); |
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103 | |||
104 | 3 | if ($currentPage > 1) { |
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105 | 2 | $pagination['links']['prev'] = $paginator->getUrl($currentPage - 1); |
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106 | 2 | } |
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107 | |||
108 | 3 | if ($currentPage < $lastPage) { |
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109 | 2 | $pagination['links']['next'] = $paginator->getUrl($currentPage + 1); |
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110 | 2 | } |
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111 | |||
112 | 3 | $pagination['links']['last'] = $paginator->getUrl($lastPage); |
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113 | |||
114 | 3 | return ['pagination' => $pagination]; |
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115 | } |
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116 | |||
117 | /** |
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118 | * Serialize the meta. |
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119 | * |
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120 | * @param array $meta |
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121 | * |
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122 | * @return array |
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123 | */ |
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124 | 24 | public function meta(array $meta) |
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125 | { |
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126 | 24 | if (empty($meta)) { |
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127 | 19 | return []; |
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128 | } |
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129 | |||
130 | 5 | $result['meta'] = $meta; |
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131 | |||
132 | 5 | if (array_key_exists('pagination', $result['meta'])) { |
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133 | 3 | $result['links'] = $result['meta']['pagination']['links']; |
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134 | 3 | unset($result['meta']['pagination']['links']); |
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135 | 3 | } |
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136 | |||
137 | 5 | return $result; |
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138 | } |
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139 | |||
140 | /** |
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141 | * @return array |
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142 | */ |
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143 | 2 | public function null() |
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144 | { |
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145 | return [ |
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146 | 2 | 'data' => null, |
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147 | 2 | ]; |
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148 | } |
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149 | |||
150 | /** |
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151 | * Serialize the included data. |
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152 | * |
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153 | * @param ResourceInterface $resource |
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154 | * @param array $data |
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155 | * |
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156 | * @return array |
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157 | */ |
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158 | 24 | public function includedData(ResourceInterface $resource, array $data) |
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159 | { |
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160 | 24 | list($serializedData, $linkedIds) = $this->pullOutNestedIncludedData($data); |
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161 | |||
162 | 24 | foreach ($data as $value) { |
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163 | 24 | foreach ($value as $includeObject) { |
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164 | 15 | if ($this->isNull($includeObject) || $this->isEmpty($includeObject)) { |
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165 | 4 | continue; |
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166 | } |
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167 | 13 | if ($this->isCollection($includeObject)) { |
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168 | 7 | $includeObjects = $includeObject['data']; |
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169 | 7 | } |
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170 | else { |
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171 | 9 | $includeObjects = [$includeObject['data']]; |
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172 | } |
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173 | |||
174 | 13 | View Code Duplication | foreach ($includeObjects as $object) { |
175 | 13 | $includeType = $object['type']; |
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176 | 13 | $includeId = $object['id']; |
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177 | 13 | $cacheKey = "$includeType:$includeId"; |
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178 | 13 | if (!array_key_exists($cacheKey, $linkedIds)) { |
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179 | 13 | $serializedData[] = $object; |
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180 | 13 | $linkedIds[$cacheKey] = $object; |
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181 | 13 | } |
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182 | 13 | } |
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183 | 24 | } |
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184 | 24 | } |
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185 | |||
186 | 24 | return empty($serializedData) ? [] : ['included' => $serializedData]; |
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187 | } |
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188 | |||
189 | /** |
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190 | * Indicates if includes should be side-loaded. |
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191 | * |
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192 | * @return bool |
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193 | */ |
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194 | 25 | public function sideloadIncludes() |
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198 | |||
199 | /** |
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200 | * @param array $data |
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201 | * @param array $includedData |
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202 | * |
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203 | * @return array |
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204 | */ |
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205 | 24 | public function injectData($data, $includedData) |
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215 | |||
216 | /** |
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217 | * Hook to manipulate the final sideloaded includes. |
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218 | * |
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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 $data |
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226 | * |
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227 | * @return array |
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228 | */ |
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229 | 24 | public function filterIncludes($includedData, $data) |
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250 | |||
251 | /** |
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252 | * Get the mandatory fields for the serializer |
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253 | * |
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254 | * @return array |
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255 | */ |
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256 | public function getMandatoryFields() |
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260 | |||
261 | /** |
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262 | * Filter function to delete root objects from array. |
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263 | * |
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264 | * @param array $object |
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265 | * |
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266 | * @return bool |
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267 | */ |
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268 | 13 | protected function filterRootObject($object) |
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272 | |||
273 | /** |
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274 | * Set the root objects of the JSON API tree. |
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275 | * |
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276 | * @param array $objects |
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277 | */ |
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278 | protected function setRootObjects(array $objects = []) |
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284 | |||
285 | /** |
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286 | * Determines whether an object is a root object of the JSON API tree. |
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287 | * |
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288 | * @param array $object |
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289 | * |
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290 | * @return bool |
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291 | */ |
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292 | 13 | protected function isRootObject($object) |
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297 | |||
298 | /** |
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299 | * @param array $data |
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300 | * |
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301 | * @return bool |
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302 | */ |
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303 | 15 | protected function isCollection($data) |
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308 | |||
309 | /** |
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310 | * @param array $data |
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311 | * |
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312 | * @return bool |
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313 | */ |
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314 | 15 | protected function isNull($data) |
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318 | |||
319 | /** |
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320 | * @param array $data |
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321 | * |
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322 | * @return bool |
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323 | */ |
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324 | 14 | protected function isEmpty($data) { |
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327 | |||
328 | /** |
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329 | * @param array $data |
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330 | * @param array $relationships |
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331 | * |
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332 | * @return mixed |
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333 | */ |
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334 | 15 | protected function fillRelationships($data, $relationships) |
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360 | |||
361 | /** |
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362 | * @param array $includedData |
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363 | * |
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364 | * @return array |
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365 | */ |
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366 | 24 | protected function parseRelationships($includedData) |
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410 | |||
411 | /** |
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412 | * @param array $data |
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413 | * |
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414 | * @return mixed |
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415 | */ |
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416 | 25 | protected function getIdFromData(array $data) |
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425 | |||
426 | /** |
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427 | * Keep all sideloaded inclusion data on the top level. |
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428 | * |
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429 | * @param array $data |
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430 | * |
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431 | * @return array |
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432 | */ |
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433 | 24 | protected function pullOutNestedIncludedData(array $data) |
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457 | |||
458 | /** |
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459 | * Whether or not the serializer should include `links` for resource objects. |
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460 | * |
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461 | * @return bool |
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462 | */ |
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463 | 24 | protected function shouldIncludeLinks() |
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467 | } |
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468 |