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
$myArrayis initialized the first time when the foreach loop is entered. You can also see that the value of thebarkey 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.