Youshido /
GraphQL
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 Processor 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 Processor, and based on these observations, apply Extract Interface, too.
| 1 | <?php |
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| 39 | class Processor |
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| 40 | { |
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| 41 | |||
| 42 | const TYPE_NAME_QUERY = '__typename'; |
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| 43 | |||
| 44 | /** @var array */ |
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| 45 | protected $data; |
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| 46 | |||
| 47 | /** @var ResolveValidatorInterface */ |
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| 48 | protected $resolveValidator; |
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| 49 | |||
| 50 | /** @var ExecutionContext */ |
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| 51 | protected $executionContext; |
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| 52 | |||
| 53 | /** @var int */ |
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| 54 | protected $maxComplexity; |
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| 55 | |||
| 56 | 31 | public function __construct(AbstractSchema $schema) |
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| 57 | { |
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| 58 | /** |
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| 59 | * This will be removed in 1.4 when __construct signature is changed to accept ExecutionContext |
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| 60 | */ |
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| 61 | 31 | if (empty($this->executionContext)) { |
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| 62 | 31 | $this->executionContext = new ExecutionContext($schema); |
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| 63 | 31 | $this->executionContext->setContainer(new Container()); |
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| 64 | } |
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| 65 | 31 | $this->resolveValidator = new ResolveValidator($this->executionContext); |
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| 66 | 31 | } |
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| 67 | |||
| 68 | 29 | public function processPayload($payload, $variables = [], $reducers = []) |
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| 69 | { |
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| 70 | 29 | $this->data = []; |
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| 71 | |||
| 72 | try { |
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| 73 | 29 | $this->parseAndCreateRequest($payload, $variables); |
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| 74 | |||
| 75 | 29 | $queryType = $this->executionContext->getSchema()->getQueryType(); |
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| 76 | 29 | $mutationType = $this->executionContext->getSchema()->getMutationType(); |
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| 77 | |||
| 78 | 29 | if ($this->maxComplexity) { |
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| 79 | 1 | $reducers[] = new MaxComplexityQueryVisitor($this->maxComplexity); |
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| 80 | } |
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| 81 | |||
| 82 | 29 | $this->reduceQuery($queryType, $mutationType, $reducers); |
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| 83 | |||
| 84 | 29 | foreach ($this->executionContext->getRequest()->getOperationsInOrder() as $operation) { |
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| 85 | 29 | if ($operationResult = $this->executeOperation($operation, $operation instanceof Mutation ? $mutationType : $queryType)) { |
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| 86 | 29 | $this->data = array_merge($this->data, $operationResult); |
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| 87 | }; |
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| 88 | } |
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| 89 | |||
| 90 | 4 | } catch (\Exception $e) { |
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| 91 | 4 | $this->executionContext->addError($e); |
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| 92 | } |
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| 93 | |||
| 94 | 29 | return $this; |
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| 95 | } |
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| 96 | |||
| 97 | 29 | protected function parseAndCreateRequest($payload, $variables = []) |
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| 98 | { |
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| 99 | 29 | if (empty($payload)) { |
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| 100 | 1 | throw new \Exception('Must provide an operation.'); |
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| 101 | } |
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| 102 | |||
| 103 | 29 | $parser = new Parser(); |
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| 104 | 29 | $request = new Request($parser->parse($payload), $variables); |
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| 105 | |||
| 106 | 29 | (new RequestValidator())->validate($request); |
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| 107 | |||
| 108 | 29 | $this->executionContext->setRequest($request); |
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| 109 | 29 | } |
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| 110 | |||
| 111 | /** |
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| 112 | * @param Query|Field $query |
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| 113 | * @param AbstractObjectType $currentLevelSchema |
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| 114 | * |
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| 115 | * @return array|bool|mixed |
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| 116 | */ |
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| 117 | 29 | protected function executeOperation(Query $query, $currentLevelSchema) |
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| 133 | |||
| 134 | /** |
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| 135 | * @param Query $query |
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| 136 | * @param FieldInterface $field |
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| 137 | * @param $contextValue |
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| 138 | * |
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| 139 | * @return array|mixed|null |
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| 140 | */ |
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| 141 | 26 | protected function processQueryAST(Query $query, FieldInterface $field, $contextValue = null) |
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| 142 | { |
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| 143 | 26 | if (!$this->resolveValidator->validateArguments($field, $query, $this->executionContext->getRequest())) { |
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| 144 | return null; |
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| 145 | } |
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| 146 | |||
| 147 | 26 | $resolvedValue = $this->resolveFieldValue($field, $contextValue, $query->getFields(), $this->parseArgumentsValues($field, $query)); |
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| 148 | |||
| 149 | 26 | if (!$this->resolveValidator->isValidValueForField($field, $resolvedValue)) { |
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| 150 | 2 | return null; |
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| 151 | } |
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| 152 | |||
| 153 | 26 | return $this->collectValueForQueryWithType($query, $field->getType(), $resolvedValue); |
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| 154 | } |
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| 155 | |||
| 156 | /** |
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| 157 | * @param Query|Mutation $query |
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| 158 | * @param AbstractType $fieldType |
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| 159 | * @param mixed $resolvedValue |
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| 160 | * |
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| 161 | * @return array|mixed |
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| 162 | * @throws ResolveException |
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| 163 | */ |
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| 164 | 26 | protected function collectValueForQueryWithType(Query $query, AbstractType $fieldType, $resolvedValue) |
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| 165 | { |
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| 166 | 26 | if (is_null($resolvedValue)) { |
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| 167 | 7 | return null; |
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| 168 | } |
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| 169 | |||
| 170 | 24 | $value = []; |
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| 171 | |||
| 172 | 24 | $fieldType = $fieldType->getNullableType(); |
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| 173 | |||
| 174 | 24 | if (!$query->hasFields()) { |
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| 175 | 5 | $fieldType = $this->resolveValidator->resolveTypeIfAbstract($fieldType, $resolvedValue); |
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| 176 | |||
| 177 | 5 | if (!TypeService::isLeafType($fieldType->getNamedType())) { |
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| 178 | throw new ResolveException(sprintf('You have to specify fields for "%s"', $query->getName())); |
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| 179 | } |
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| 180 | 5 | if (TypeService::isScalarType($fieldType)) { |
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| 181 | 5 | return $this->getOutputValue($fieldType, $resolvedValue); |
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| 182 | } |
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| 183 | } |
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| 184 | |||
| 185 | 21 | if ($fieldType->getKind() == TypeMap::KIND_LIST) { |
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| 186 | 10 | if (!$this->resolveValidator->hasArrayAccess($resolvedValue)) return null; |
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| 187 | |||
| 188 | 10 | $namedType = $fieldType->getNamedType(); |
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| 189 | 10 | $validItemStructure = false; |
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| 190 | |||
| 191 | 10 | foreach ($resolvedValue as $resolvedValueItem) { |
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| 192 | 9 | $value[] = []; |
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| 193 | 9 | $index = count($value) - 1; |
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| 194 | |||
| 195 | 9 | $namedType = $this->resolveValidator->resolveTypeIfAbstract($namedType, $resolvedValueItem); |
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| 196 | |||
| 197 | 9 | if (!$validItemStructure) { |
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| 198 | 9 | if (!$namedType->isValidValue($resolvedValueItem)) { |
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| 199 | 1 | $this->executionContext->addError(new ResolveException(sprintf('Not valid resolve value in %s field', $query->getName()))); |
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| 200 | 1 | $value[$index] = null; |
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| 201 | 1 | continue; |
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| 202 | } |
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| 203 | 8 | $validItemStructure = true; |
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| 204 | } |
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| 205 | |||
| 206 | 10 | $value[$index] = $this->processQueryFields($query, $namedType, $resolvedValueItem, $value[$index]); |
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| 207 | } |
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| 208 | } else { |
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| 209 | 21 | $value = $this->processQueryFields($query, $fieldType, $resolvedValue, $value); |
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| 210 | } |
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| 211 | |||
| 212 | 21 | return $value; |
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| 213 | } |
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| 214 | |||
| 215 | /** |
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| 216 | * @param FieldAst $fieldAst |
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| 217 | * @param FieldInterface $field |
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| 218 | * |
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| 219 | * @param mixed $contextValue |
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| 220 | * |
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| 221 | * @return array|mixed|null |
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| 222 | * @throws ResolveException |
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| 223 | * @throws \Exception |
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| 224 | */ |
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| 225 | 20 | protected function processFieldAST(FieldAst $fieldAst, FieldInterface $field, $contextValue) |
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| 246 | |||
| 247 | 26 | protected function createResolveInfo($field, $fields) |
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| 251 | |||
| 252 | /** |
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| 253 | * @param $contextValue |
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| 254 | * @param FieldAst $fieldAst |
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| 255 | * @param FieldInterface $field |
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| 256 | * |
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| 257 | * @throws \Exception |
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| 258 | * |
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| 259 | * @return mixed |
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| 260 | */ |
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| 261 | 20 | protected function getPreResolvedValue($contextValue, FieldAst $fieldAst, FieldInterface $field) |
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| 262 | { |
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| 263 | 20 | if ($field->hasArguments() && !$this->resolveValidator->validateArguments($field, $fieldAst, $this->executionContext->getRequest())) { |
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| 264 | return null; |
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| 265 | } |
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| 266 | |||
| 267 | 20 | return $this->resolveFieldValue($field, $contextValue, [$fieldAst], $fieldAst->getKeyValueArguments()); |
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| 268 | |||
| 269 | } |
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| 270 | |||
| 271 | 26 | protected function resolveFieldValue(FieldInterface $field, $contextValue, array $fields, array $args) |
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| 275 | |||
| 276 | /** |
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| 277 | * @param $field FieldInterface |
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| 278 | * @param $query Query |
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| 279 | * |
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| 280 | * @return array |
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| 281 | */ |
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| 282 | 26 | protected function parseArgumentsValues(FieldInterface $field, Query $query) |
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| 293 | |||
| 294 | /** |
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| 295 | * @param $query Query|FragmentInterface |
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| 296 | * @param $queryType AbstractObjectType|TypeInterface|Field|AbstractType |
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| 297 | * @param $resolvedValue mixed |
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| 298 | * @param $value array |
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| 299 | * |
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| 300 | * @throws \Exception |
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| 301 | * |
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| 302 | * @return array |
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| 303 | */ |
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| 304 | 21 | protected function processQueryFields($query, AbstractType $queryType, $resolvedValue, $value) |
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| 376 | |||
| 377 | protected function getFieldValidatedValue(FieldInterface $field, $value) |
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| 381 | |||
| 382 | 23 | protected function getOutputValue(AbstractType $type, $value) |
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| 386 | |||
| 387 | 29 | public function getResponseData() |
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| 401 | |||
| 402 | /** |
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| 403 | * You can access ExecutionContext to check errors and inject dependencies |
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| 404 | * |
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| 405 | * @return ExecutionContext |
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| 406 | */ |
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| 407 | 9 | public function getExecutionContext() |
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| 411 | |||
| 412 | /** |
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| 413 | * Convenience function for attaching a MaxComplexityQueryVisitor($max) to the next processor run |
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| 414 | * |
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| 415 | * @param int $max |
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| 416 | */ |
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| 417 | 1 | public function setMaxComplexity($max) |
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| 421 | |||
| 422 | /** |
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| 423 | * Apply all of $reducers to this query. Example reducer operations: checking for maximum query complexity, |
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| 424 | * performing look-ahead query planning, etc. |
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| 425 | * |
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| 426 | * @param AbstractType $queryType |
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| 427 | * @param AbstractType $mutationType |
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| 428 | * @param AbstractQueryVisitor[] $reducers |
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| 429 | */ |
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| 430 | 29 | protected function reduceQuery($queryType, $mutationType, array $reducers) |
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| 438 | |||
| 439 | /** |
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| 440 | * Entry point for the `walkQuery` routine. Execution bounces between here, where the reducer's ->visit() method |
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| 441 | * is invoked, and `walkQuery` where we send in the scores from the `visit` call. |
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| 442 | * |
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| 443 | * @param Query $query |
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| 444 | * @param AbstractType $currentLevelSchema |
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| 445 | * @param AbstractQueryVisitor $reducer |
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| 446 | */ |
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| 447 | 2 | protected function doVisit(Query $query, $currentLevelSchema, $reducer) |
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| 474 | |||
| 475 | /** |
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| 476 | * Coroutine to walk the query and schema in DFS manner (see AbstractQueryVisitor docs for more info) and yield a |
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| 477 | * tuple of (queryNode, schemaNode, childScore) |
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| 478 | * |
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| 479 | * childScore costs are accumulated via values sent into the coroutine. |
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| 480 | * |
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| 481 | * Most of the branching in this function is just to handle the different types in a query: Queries, Unions, |
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| 482 | * Fragments (anonymous and named), and Fields. The core of the function is simple: recurse until we hit the base |
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| 483 | * case of a Field and yield that back up to the visitor up in `doVisit`. |
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| 484 | * |
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| 485 | * @param Query|Field|FragmentInterface $queryNode |
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| 486 | * @param FieldInterface $currentLevelAST |
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| 487 | * |
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| 488 | * @return \Generator |
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| 489 | */ |
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| 490 | 2 | protected function walkQuery($queryNode, FieldInterface $currentLevelAST) |
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| 543 | } |
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| 544 |
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There are different options of fixing this problem.
If you want to be on the safe side, you can add an additional type-check:
If you are sure that the expression is traversable, you might want to add a doc comment cast to improve IDE auto-completion and static analysis:
Mark the issue as a false-positive: Just hover the remove button, in the top-right corner of this issue for more options.