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 SchemaPluginBase 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 SchemaPluginBase, and based on these observations, apply Extract Interface, too.
1 | <?php |
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27 | abstract class SchemaPluginBase extends PluginBase implements SchemaPluginInterface, SchemaBuilderInterface, ContainerFactoryPluginInterface, CacheableDependencyInterface { |
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28 | |||
29 | /** |
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30 | * The field plugin manager. |
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31 | * |
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32 | * @var \Drupal\graphql\Plugin\FieldPluginManager |
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33 | */ |
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34 | protected $fieldManager; |
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35 | |||
36 | /** |
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37 | * The mutation plugin manager. |
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38 | * |
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39 | * @var \Drupal\graphql\Plugin\MutationPluginManager |
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40 | */ |
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41 | protected $mutationManager; |
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42 | |||
43 | /** |
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44 | * The subscription plugin manager. |
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45 | * |
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46 | * @var \Drupal\graphql\Plugin\SubscriptionPluginManager |
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47 | */ |
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48 | protected $subscriptionManager; |
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49 | |||
50 | /** |
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51 | * The type manager aggregator service. |
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52 | * |
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53 | * @var \Drupal\graphql\Plugin\TypePluginManagerAggregator |
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54 | */ |
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55 | protected $typeManagers; |
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56 | |||
57 | /** |
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58 | * Static cache of field definitions. |
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59 | * |
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60 | * @var array |
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61 | */ |
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62 | protected $fields = []; |
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63 | |||
64 | /** |
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65 | * Static cache of mutation definitions. |
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66 | * |
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67 | * @var array |
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68 | */ |
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69 | protected $mutations = []; |
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70 | |||
71 | /** |
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72 | * Static cache of subscription definitions. |
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73 | * |
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74 | * @var array |
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75 | */ |
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76 | protected $subscriptions = []; |
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77 | |||
78 | /** |
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79 | * Static cache of type instances. |
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80 | * |
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81 | * @var array |
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82 | */ |
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83 | protected $types = []; |
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84 | |||
85 | /** |
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86 | * The service parameters |
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87 | * |
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88 | * @var array |
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89 | */ |
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90 | protected $parameters; |
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91 | |||
92 | /** |
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93 | * The query provider service. |
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94 | * |
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95 | * @var \Drupal\graphql\GraphQL\QueryProvider\QueryProviderInterface |
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96 | */ |
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97 | protected $queryProvider; |
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98 | |||
99 | /** |
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100 | * The current user. |
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101 | * |
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102 | * @var \Drupal\Core\Session\AccountProxyInterface |
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103 | */ |
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104 | protected $currentUser; |
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105 | |||
106 | /** |
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107 | * {@inheritdoc} |
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108 | */ |
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109 | public static function create(ContainerInterface $container, array $configuration, $plugin_id, $plugin_definition) { |
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123 | |||
124 | /** |
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125 | * SchemaPluginBase constructor. |
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126 | * |
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127 | * @param array $configuration |
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128 | * The plugin configuration array. |
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129 | * @param string $pluginId |
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130 | * The plugin id. |
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131 | * @param array $pluginDefinition |
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132 | * The plugin definition array. |
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133 | * @param \Drupal\graphql\Plugin\FieldPluginManager $fieldManager |
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134 | * The field plugin manager. |
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135 | * @param \Drupal\graphql\Plugin\MutationPluginManager $mutationManager |
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136 | * The mutation plugin manager. |
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137 | * @param \Drupal\graphql\Plugin\SubscriptionPluginManager $subscriptionManager |
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138 | * The subscription plugin manager. |
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139 | * @param \Drupal\graphql\Plugin\TypePluginManagerAggregator $typeManagers |
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140 | * The type manager aggregator service. |
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141 | * @param \Drupal\graphql\GraphQL\QueryProvider\QueryProviderInterface $queryProvider |
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142 | * The query provider service. |
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143 | * @param \Drupal\Core\Session\AccountProxyInterface $currentUser |
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144 | * The current user. |
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145 | * @param array $parameters |
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146 | */ |
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147 | public function __construct( |
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168 | |||
169 | /** |
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170 | * {@inheritdoc} |
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171 | */ |
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172 | public function getSchema() { |
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210 | |||
211 | /** |
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212 | * {@inheritdoc} |
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213 | */ |
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214 | public function validateSchema() { |
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217 | |||
218 | /** |
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219 | * {@inheritdoc} |
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220 | */ |
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221 | public function getServer() { |
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263 | |||
264 | /** |
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265 | /** |
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266 | * {@inheritdoc} |
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267 | */ |
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268 | public function hasFields($type) { |
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271 | |||
272 | /** |
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273 | * {@inheritdoc} |
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274 | */ |
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275 | public function hasMutations() { |
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278 | |||
279 | /** |
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280 | * {@inheritdoc} |
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281 | */ |
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282 | public function hasSubscriptions() { |
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285 | |||
286 | /** |
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287 | * {@inheritdoc} |
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288 | */ |
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289 | public function hasType($name) { |
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292 | |||
293 | /** |
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294 | * {@inheritdoc} |
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295 | */ |
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296 | public function getFields($type) { |
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308 | |||
309 | /** |
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310 | * {@inheritdoc} |
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311 | */ |
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312 | public function getMutations() { |
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315 | |||
316 | /** |
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317 | * {@inheritdoc} |
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318 | */ |
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319 | public function getSubscriptions() { |
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322 | |||
323 | /** |
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324 | * {@inheritdoc} |
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325 | */ |
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326 | public function getTypes() { |
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331 | |||
332 | /** |
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333 | * {@inheritdoc} |
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334 | */ |
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335 | public function getSubTypes($name) { |
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339 | |||
340 | /** |
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341 | * {@inheritdoc} |
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342 | */ |
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343 | public function resolveType($name, $value, ResolveContext $context, ResolveInfo $info) { |
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361 | |||
362 | /** |
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363 | * {@inheritdoc} |
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364 | */ |
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365 | public function getType($name) { |
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380 | |||
381 | /** |
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382 | * {@inheritdoc} |
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383 | */ |
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384 | public function processMutations($mutations) { |
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387 | |||
388 | /** |
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389 | * {@inheritdoc} |
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390 | */ |
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391 | public function processSubscriptions($subscriptions) { |
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394 | |||
395 | /** |
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396 | * {@inheritdoc} |
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397 | */ |
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398 | public function processFields($fields) { |
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401 | |||
402 | /** |
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403 | * {@inheritdoc} |
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404 | */ |
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405 | public function processArguments($args) { |
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412 | |||
413 | /** |
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414 | * {@inheritdoc} |
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415 | */ |
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416 | public function processType($type) { |
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423 | |||
424 | /** |
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425 | * Retrieves the type instance for the given reference. |
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426 | * |
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427 | * @param array $type |
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428 | * The type reference. |
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429 | * |
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430 | * @return \GraphQL\Type\Definition\Type |
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431 | * The type instance. |
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432 | */ |
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433 | protected function buildType($type) { |
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442 | |||
443 | /** |
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444 | * Retrieves the field definition for a given field reference. |
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445 | * |
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446 | * @param array $field |
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447 | * The type reference. |
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448 | * |
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449 | * @return array |
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450 | * The field definition. |
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451 | */ |
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452 | View Code Duplication | protected function buildField($field) { |
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460 | |||
461 | /** |
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462 | * Retrieves the mutation definition for a given field reference. |
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463 | * |
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464 | * @param array $mutation |
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465 | * The mutation reference. |
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466 | * |
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467 | * @return array |
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468 | * The mutation definition. |
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469 | */ |
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470 | View Code Duplication | protected function buildMutation($mutation) { |
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478 | |||
479 | /** |
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480 | * Retrieves the subscription definition for a given field reference. |
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481 | * |
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482 | * @param array $mutation |
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483 | * The subscription reference. |
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484 | * |
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485 | * @return array |
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486 | * The subscription definition. |
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487 | */ |
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488 | View Code Duplication | protected function buildSubscription($subscription) { |
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496 | |||
497 | /** |
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498 | * {@inheritdoc} |
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499 | */ |
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500 | public function getCacheContexts() { |
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503 | |||
504 | /** |
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505 | * {@inheritdoc} |
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506 | */ |
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507 | public function getCacheTags() { |
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510 | |||
511 | /** |
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512 | * {@inheritdoc} |
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513 | */ |
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514 | public function getCacheMaxAge() { |
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517 | } |
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518 |
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.