Complex classes like IdentifierAndResource 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 IdentifierAndResource, and based on these observations, apply Extract Interface, too.
1 | <?php declare(strict_types=1); |
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38 | class IdentifierAndResource implements ResourceInterface |
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39 | { |
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40 | /** @var string */ |
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41 | public const MSG_NO_SCHEMA_FOUND = 'No Schema found for resource `%s` at path `%s`.'; |
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42 | |||
43 | /** @var string */ |
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44 | public const MSG_INVALID_OPERATION = 'Invalid operation.'; |
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45 | |||
46 | /** |
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47 | * @var PositionInterface |
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48 | */ |
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49 | private $position; |
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50 | |||
51 | /** |
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52 | * @var FactoryInterface |
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53 | */ |
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54 | private $factory; |
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55 | |||
56 | /** |
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57 | * @var SchemaContainerInterface |
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58 | */ |
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59 | private $schemaContainer; |
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60 | |||
61 | /** |
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62 | * @var SchemaInterface |
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63 | */ |
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64 | private $schema; |
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65 | |||
66 | /** |
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67 | * @var mixed |
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68 | */ |
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69 | private $data; |
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70 | |||
71 | /** |
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72 | * @var string |
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73 | */ |
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74 | private $index; |
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75 | |||
76 | /** |
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77 | * @var string |
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78 | */ |
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79 | private $type; |
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80 | |||
81 | /** |
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82 | * @var null|array |
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83 | */ |
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84 | private $links = null; |
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85 | |||
86 | /** |
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87 | * @var null|array |
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88 | */ |
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89 | private $relationshipsCache = null; |
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90 | |||
91 | /** |
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92 | * @param PositionInterface $position |
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93 | * @param FactoryInterface $factory |
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94 | * @param SchemaContainerInterface $container |
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95 | * @param mixed $data |
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96 | */ |
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97 | 59 | public function __construct( |
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98 | PositionInterface $position, |
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99 | FactoryInterface $factory, |
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100 | SchemaContainerInterface $container, |
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101 | $data |
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102 | ) { |
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103 | 59 | $schema = $container->getSchema($data); |
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104 | $this |
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105 | 59 | ->setPosition($position) |
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106 | 59 | ->setFactory($factory) |
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107 | 59 | ->setSchemaContainer($container) |
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108 | 59 | ->setSchema($schema) |
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109 | 59 | ->setData($data); |
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110 | 59 | } |
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111 | |||
112 | /** |
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113 | * @inheritdoc |
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114 | */ |
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115 | 59 | public function getPosition(): PositionInterface |
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116 | { |
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117 | 59 | return $this->position; |
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118 | } |
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119 | |||
120 | /** |
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121 | * @inheritdoc |
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122 | */ |
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123 | 59 | public function getId(): ?string |
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124 | { |
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125 | 59 | return $this->index; |
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126 | } |
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127 | |||
128 | /** |
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129 | * @inheritdoc |
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130 | */ |
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131 | 59 | public function getType(): string |
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132 | { |
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133 | 59 | return $this->type; |
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134 | } |
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135 | |||
136 | /** |
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137 | * @inheritdoc |
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138 | */ |
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139 | 31 | public function hasIdentifierMeta(): bool |
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140 | { |
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141 | 31 | return $this->getSchema()->hasIdentifierMeta($this->getData()); |
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142 | } |
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143 | |||
144 | /** |
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145 | * @inheritdoc |
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146 | */ |
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147 | public function getIdentifierMeta() |
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148 | { |
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149 | return $this->getSchema()->getIdentifierMeta($this->getData()); |
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150 | } |
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151 | |||
152 | /** |
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153 | * @inheritdoc |
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154 | */ |
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155 | 56 | public function getAttributes(): iterable |
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156 | { |
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157 | 56 | return $this->getSchema()->getAttributes($this->getData()); |
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158 | } |
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159 | |||
160 | /** |
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161 | * @inheritdoc |
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162 | */ |
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163 | 59 | public function getRelationships(): iterable |
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164 | { |
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165 | 59 | if ($this->relationshipsCache !== null) { |
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166 | 56 | yield from $this->relationshipsCache; |
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167 | |||
168 | 55 | return; |
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169 | } |
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170 | |||
171 | 59 | $this->relationshipsCache = []; |
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172 | |||
173 | 59 | $currentType = $this->getType(); |
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174 | 59 | $currentPath = $this->getPosition()->getPath(); |
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175 | 59 | $nextLevel = $this->getPosition()->getLevel() + 1; |
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176 | 59 | $nextPathPrefix = empty($currentPath) === true ? '' : $currentPath . PositionInterface::PATH_SEPARATOR; |
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177 | 59 | foreach ($this->getSchema()->getRelationships($this->getData()) as $name => $description) { |
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178 | 44 | assert( |
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179 | 44 | is_string($name) === true && empty($name) === false, |
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180 | 44 | "Relationship names for type `" . $currentType . '` should be non-empty strings.' |
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181 | ); |
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182 | 44 | assert( |
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183 | 44 | is_array($description) === true && empty($description) === false, |
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184 | 44 | "Relationship `$name` for type `" . $currentType . '` should be a non-empty array.' |
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185 | ); |
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186 | |||
187 | 44 | $hasData = array_key_exists(SchemaInterface::RELATIONSHIP_DATA, $description); |
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188 | // either no data or data should be array/object/null |
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189 | 44 | assert( |
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190 | 44 | $hasData === false || |
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191 | ( |
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192 | 34 | is_array($data = $description[SchemaInterface::RELATIONSHIP_DATA]) === true || |
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193 | 29 | is_object($data) === true || |
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194 | 44 | $data === null |
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195 | ) |
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196 | ); |
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197 | |||
198 | 44 | $hasMeta = array_key_exists(SchemaInterface::RELATIONSHIP_META, $description); |
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199 | |||
200 | 44 | $addSelfLink = $description[SchemaInterface::RELATIONSHIP_LINKS_SELF] ?? |
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201 | 44 | $this->getSchema()->isAddSelfLinkInRelationshipByDefault(); |
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202 | 44 | $addRelatedLink = $description[SchemaInterface::RELATIONSHIP_LINKS_RELATED] ?? |
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203 | 44 | $this->getSchema()->isAddRelatedLinkInRelationshipByDefault(); |
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204 | 44 | assert(is_bool($addSelfLink) === true || $addSelfLink instanceof LinkInterface); |
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205 | 44 | assert(is_bool($addRelatedLink) === true || $addRelatedLink instanceof LinkInterface); |
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206 | |||
207 | 44 | $schemaLinks = array_key_exists(SchemaInterface::RELATIONSHIP_LINKS, $description) === true ? |
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208 | 44 | $description[SchemaInterface::RELATIONSHIP_LINKS] : []; |
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209 | 44 | assert(is_array($schemaLinks)); |
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210 | |||
211 | // if `self` or `related` link was given as LinkInterface merge it with the other links |
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212 | 44 | if (is_bool($addSelfLink) === false) { |
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213 | $extraSchemaLinks[LinkInterface::SELF] = $addSelfLink; |
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214 | $addSelfLink = false; |
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215 | } |
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216 | 44 | if (is_bool($addRelatedLink) === false) { |
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217 | $extraSchemaLinks[LinkInterface::RELATED] = $addRelatedLink; |
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218 | $addRelatedLink = false; |
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219 | } |
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220 | 44 | if (isset($extraSchemaLinks) === true) { |
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221 | // IDE do not understand it's defined without he line below |
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222 | assert(isset($extraSchemaLinks)); |
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223 | $schemaLinks = array_merge($extraSchemaLinks, $schemaLinks); |
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224 | unset($extraSchemaLinks); |
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225 | } |
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226 | 44 | assert(is_bool($addSelfLink) === true && is_bool($addRelatedLink) === true); |
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227 | |||
228 | 44 | $hasLinks = $addSelfLink === true || $addRelatedLink === true || empty($schemaLinks) === false; |
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229 | 44 | assert( |
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230 | 44 | $hasData || $hasMeta || $hasLinks, |
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231 | 44 | "Relationship `$name` for type `" . $currentType . |
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232 | 44 | '` MUST contain at least one of the following: links, data or meta.' |
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233 | ); |
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234 | |||
235 | 44 | $nextPosition = $this->getFactory()->createPosition( |
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236 | 44 | $nextLevel, |
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237 | 44 | $nextPathPrefix . $name, |
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238 | 44 | $currentType, |
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239 | 44 | $name |
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240 | ); |
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241 | |||
242 | 44 | $relationshipData = $hasData === true ? $this->parseData( |
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243 | 34 | $nextPosition, |
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244 | 34 | $description[SchemaInterface::RELATIONSHIP_DATA] |
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245 | 44 | ) : null; |
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246 | |||
247 | 44 | $relationship = $this->getFactory()->createRelationship( |
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248 | 44 | $nextPosition, |
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249 | 44 | $hasData, |
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250 | 44 | $relationshipData, |
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251 | 44 | $hasLinks, |
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252 | 44 | $hasLinks === true ? $this->parseLinks($name, $schemaLinks, $addSelfLink, $addRelatedLink) : null, |
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253 | 44 | $hasMeta, |
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254 | 44 | $hasMeta === true ? $description[SchemaInterface::RELATIONSHIP_META] : null |
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255 | ); |
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256 | |||
257 | 44 | $this->relationshipsCache[$name] = $relationship; |
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258 | |||
259 | 44 | yield $name => $relationship; |
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260 | } |
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261 | 59 | } |
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262 | |||
263 | /** |
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264 | * @inheritdoc |
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265 | */ |
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266 | 56 | public function hasLinks(): bool |
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267 | { |
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268 | 56 | $this->cacheLinks(); |
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269 | |||
270 | 56 | return empty($this->links) === false; |
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271 | } |
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272 | |||
273 | /** |
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274 | * @inheritdoc |
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275 | */ |
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276 | 55 | public function getLinks(): iterable |
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277 | { |
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278 | 55 | $this->cacheLinks(); |
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279 | |||
280 | 55 | return $this->links; |
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281 | } |
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282 | |||
283 | /** |
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284 | * @inheritdoc |
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285 | */ |
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286 | 56 | public function hasResourceMeta(): bool |
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287 | { |
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288 | 56 | return $this->getSchema()->hasResourceMeta($this->getData()); |
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289 | } |
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290 | |||
291 | /** |
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292 | * @inheritdoc |
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293 | */ |
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294 | public function getResourceMeta() |
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295 | { |
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296 | return $this->getSchema()->getResourceMeta($this->getData()); |
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297 | } |
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298 | |||
299 | /** |
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300 | * @inheritdoc |
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301 | */ |
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302 | 59 | protected function setPosition(PositionInterface $position): self |
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303 | { |
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304 | 59 | assert($position->getLevel() >= ParserInterface::ROOT_LEVEL); |
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305 | |||
306 | 59 | $this->position = $position; |
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307 | |||
308 | 59 | return $this; |
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309 | } |
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310 | |||
311 | /** |
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312 | * @return FactoryInterface |
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313 | */ |
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314 | 44 | protected function getFactory(): FactoryInterface |
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315 | { |
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316 | 44 | return $this->factory; |
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317 | } |
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318 | |||
319 | /** |
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320 | * @param FactoryInterface $factory |
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321 | * |
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322 | * @return self |
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323 | */ |
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324 | 59 | protected function setFactory(FactoryInterface $factory): self |
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325 | { |
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326 | 59 | $this->factory = $factory; |
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327 | |||
328 | 59 | return $this; |
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329 | } |
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330 | |||
331 | /** |
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332 | * @return SchemaContainerInterface |
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333 | */ |
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334 | 34 | protected function getSchemaContainer(): SchemaContainerInterface |
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335 | { |
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336 | 34 | return $this->schemaContainer; |
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337 | } |
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338 | |||
339 | /** |
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340 | * @param SchemaContainerInterface $container |
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341 | * |
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342 | * @return self |
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343 | */ |
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344 | 59 | protected function setSchemaContainer(SchemaContainerInterface $container): self |
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345 | { |
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346 | 59 | $this->schemaContainer = $container; |
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347 | |||
348 | 59 | return $this; |
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349 | } |
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350 | |||
351 | /** |
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352 | * @return SchemaInterface |
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353 | */ |
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354 | 59 | protected function getSchema(): SchemaInterface |
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355 | { |
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356 | 59 | return $this->schema; |
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357 | } |
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358 | |||
359 | /** |
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360 | * @param SchemaInterface $schema |
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361 | * |
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362 | * @return self |
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363 | */ |
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364 | 59 | protected function setSchema(SchemaInterface $schema): self |
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365 | { |
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366 | 59 | $this->schema = $schema; |
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367 | |||
368 | 59 | return $this; |
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369 | } |
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370 | |||
371 | /** |
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372 | * @return mixed |
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373 | */ |
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374 | 59 | protected function getData() |
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375 | { |
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376 | 59 | return $this->data; |
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377 | } |
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378 | |||
379 | /** |
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380 | * @param mixed $data |
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381 | * |
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382 | * @return self |
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383 | */ |
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384 | 59 | protected function setData($data): self |
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385 | { |
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386 | 59 | $this->data = $data; |
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387 | 59 | $this->index = $this->getSchema()->getId($data); |
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388 | 59 | $this->type = $this->getSchema()->getType(); |
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389 | |||
390 | 59 | return $this; |
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391 | } |
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392 | |||
393 | /** |
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394 | * Read and parse links from schema. |
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395 | */ |
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396 | 56 | private function cacheLinks(): void |
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397 | { |
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398 | 56 | if ($this->links === null) { |
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399 | 56 | $this->links = []; |
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400 | 56 | foreach ($this->getSchema()->getLinks($this->getData()) as $name => $link) { |
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401 | 55 | assert(is_string($name) === true && empty($name) === false); |
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402 | 55 | assert($link instanceof LinkInterface); |
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403 | 55 | $this->links[$name] = $link; |
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404 | } |
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405 | } |
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406 | 56 | } |
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407 | |||
408 | /** |
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409 | * @param PositionInterface $position |
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410 | * @param mixed $data |
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411 | * |
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412 | * @return RelationshipDataInterface |
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413 | */ |
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414 | 34 | private function parseData( |
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415 | PositionInterface $position, |
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416 | $data |
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417 | ): RelationshipDataInterface { |
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418 | // support if data is callable (e.g. a closure used to postpone actual data reading) |
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419 | 34 | if (is_callable($data) === true) { |
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420 | 1 | $data = call_user_func($data); |
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421 | } |
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422 | |||
423 | 34 | $factory = $this->getFactory(); |
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424 | 34 | if ($this->getSchemaContainer()->hasSchema($data) === true) { |
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425 | 23 | return $factory->createRelationshipDataIsResource($this->getSchemaContainer(), $position, $data); |
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426 | 33 | } elseif ($data instanceof IdentifierInterface) { |
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427 | 1 | return $factory->createRelationshipDataIsIdentifier($this->getSchemaContainer(), $position, $data); |
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428 | 32 | } elseif (is_array($data) === true) { |
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429 | 30 | return $factory->createRelationshipDataIsCollection($this->getSchemaContainer(), $position, $data); |
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430 | 6 | } elseif ($data instanceof Traversable) { |
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431 | 1 | return $factory->createRelationshipDataIsCollection( |
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432 | 1 | $this->getSchemaContainer(), |
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433 | 1 | $position, |
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434 | 1 | $data instanceof IteratorAggregate ? $data->getIterator() : $data |
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435 | ); |
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436 | 5 | } elseif ($data === null) { |
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437 | 5 | return $factory->createRelationshipDataIsNull(); |
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438 | } |
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439 | |||
440 | 1 | throw new InvalidArgumentException( |
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441 | 1 | _(static::MSG_NO_SCHEMA_FOUND, get_class($data), $position->getPath()) |
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442 | ); |
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443 | } |
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444 | |||
445 | /** |
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446 | * @param string $relationshipName |
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447 | * @param iterable $schemaLinks |
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448 | * @param bool $addSelfLink |
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449 | * @param bool $addRelatedLink |
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450 | * |
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451 | * @return iterable |
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452 | */ |
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453 | 21 | private function parseLinks( |
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491 | } |
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492 |
Adding an explicit array definition is generally preferable to implicit array definition as it guarantees a stable state of the code.
Let’s take a look at an example:
As you can see in this example, the array
$myArray
is initialized the first time when the foreach loop is entered. You can also see that the value of thebar
key is only written conditionally; thus, its value might result from a previous iteration.This might or might not be intended. To make your intention clear, your code more readible and to avoid accidental bugs, we recommend to add an explicit initialization $myArray = array() either outside or inside the foreach loop.