Complex classes like Query 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 Query, and based on these observations, apply Extract Interface, too.
1 | <?php |
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44 | final class Query implements IteratorAggregate |
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45 | { |
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46 | public const TYPE_FIND = 1; |
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47 | public const TYPE_FIND_AND_UPDATE = 2; |
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48 | public const TYPE_FIND_AND_REMOVE = 3; |
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49 | public const TYPE_INSERT = 4; |
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50 | public const TYPE_UPDATE = 5; |
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51 | public const TYPE_REMOVE = 6; |
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52 | public const TYPE_DISTINCT = 9; |
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53 | public const TYPE_COUNT = 11; |
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54 | |||
55 | public const HINT_REFRESH = 1; |
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56 | // 2 was used for HINT_SLAVE_OKAY, which was removed in 2.0 |
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57 | public const HINT_READ_PREFERENCE = 3; |
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58 | public const HINT_READ_ONLY = 5; |
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59 | |||
60 | /** |
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61 | * The DocumentManager instance. |
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62 | * |
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63 | * @var DocumentManager |
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64 | */ |
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65 | private $dm; |
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66 | |||
67 | /** |
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68 | * The ClassMetadata instance. |
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69 | * |
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70 | * @var ClassMetadata |
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71 | */ |
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72 | private $class; |
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73 | |||
74 | /** |
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75 | * Whether to hydrate results as document class instances. |
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76 | * |
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77 | * @var bool |
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78 | */ |
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79 | private $hydrate = true; |
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80 | |||
81 | /** |
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82 | * Array of primer Closure instances. |
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83 | * |
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84 | * @var array |
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85 | */ |
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86 | private $primers = []; |
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87 | |||
88 | /** |
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89 | * @var bool |
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90 | */ |
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91 | private $rewindable = true; |
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92 | |||
93 | /** |
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94 | * Hints for UnitOfWork behavior. |
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95 | * |
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96 | * @var array |
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97 | */ |
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98 | private $unitOfWorkHints = []; |
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99 | |||
100 | /** |
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101 | * The Collection instance. |
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102 | * |
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103 | * @var Collection |
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104 | */ |
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105 | protected $collection; |
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106 | |||
107 | /** |
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108 | * Query structure generated by the Builder class. |
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109 | * |
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110 | * @var array |
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111 | */ |
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112 | private $query; |
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113 | |||
114 | /** @var Iterator|null */ |
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115 | private $iterator; |
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116 | |||
117 | /** |
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118 | * Query options |
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119 | * |
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120 | * @var array |
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121 | */ |
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122 | private $options; |
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123 | |||
124 | 164 | public function __construct(DocumentManager $dm, ClassMetadata $class, Collection $collection, array $query = [], array $options = [], bool $hydrate = true, bool $refresh = false, array $primers = [], bool $readOnly = false, bool $rewindable = true) |
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125 | { |
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126 | 164 | $primers = array_filter($primers); |
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127 | |||
128 | 164 | switch ($query['type']) { |
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129 | 164 | case self::TYPE_FIND: |
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130 | 38 | case self::TYPE_FIND_AND_UPDATE: |
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131 | 26 | case self::TYPE_FIND_AND_REMOVE: |
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132 | 23 | case self::TYPE_INSERT: |
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133 | 22 | case self::TYPE_UPDATE: |
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134 | 7 | case self::TYPE_REMOVE: |
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135 | 5 | case self::TYPE_DISTINCT: |
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136 | 3 | case self::TYPE_COUNT: |
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137 | 163 | break; |
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138 | |||
139 | default: |
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140 | 1 | throw new InvalidArgumentException('Invalid query type: ' . $query['type']); |
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141 | } |
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142 | |||
143 | 163 | $this->collection = $collection; |
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144 | 163 | $this->query = $query; |
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145 | 163 | $this->options = $options; |
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146 | 163 | $this->dm = $dm; |
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147 | 163 | $this->class = $class; |
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148 | 163 | $this->hydrate = $hydrate; |
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149 | 163 | $this->primers = $primers; |
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150 | |||
151 | 163 | $this->setReadOnly($readOnly); |
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152 | 163 | $this->setRefresh($refresh); |
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153 | 163 | $this->setRewindable($rewindable); |
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154 | |||
155 | 163 | if (! isset($query['readPreference'])) { |
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156 | 155 | return; |
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157 | } |
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158 | |||
159 | 8 | $this->unitOfWorkHints[self::HINT_READ_PREFERENCE] = $query['readPreference']; |
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160 | 8 | } |
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161 | |||
162 | 64 | public function __clone() |
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163 | { |
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164 | 64 | $this->iterator = null; |
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165 | 64 | } |
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166 | |||
167 | /** |
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168 | * Return an array of information about the query structure for debugging. |
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169 | * |
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170 | * The $name parameter may be used to return a specific key from the |
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171 | * internal $query array property. If omitted, the entire array will be |
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172 | * returned. |
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173 | */ |
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174 | 27 | public function debug(?string $name = null) |
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175 | { |
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176 | 27 | return $name !== null ? $this->query[$name] : $this->query; |
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177 | } |
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178 | |||
179 | /** |
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180 | * Execute the query and returns the results. |
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181 | * |
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182 | * @return Iterator|UpdateResult|InsertOneResult|DeleteResult|array|object|int|null |
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183 | * |
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184 | * @throws MongoDBException |
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185 | */ |
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186 | 123 | public function execute() |
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187 | { |
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188 | 123 | $results = $this->runQuery(); |
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189 | |||
190 | 122 | if (! $this->hydrate) { |
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191 | 9 | return $results; |
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192 | } |
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193 | |||
194 | 116 | $uow = $this->dm->getUnitOfWork(); |
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195 | |||
196 | /* If a single document is returned from a findAndModify command and it |
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197 | * includes the identifier field, attempt hydration. |
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198 | */ |
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199 | 116 | if (($this->query['type'] === self::TYPE_FIND_AND_UPDATE || |
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200 | 116 | $this->query['type'] === self::TYPE_FIND_AND_REMOVE) && |
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201 | 116 | is_array($results) && isset($results['_id'])) { |
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202 | 5 | $results = $uow->getOrCreateDocument($this->class->name, $results, $this->unitOfWorkHints); |
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203 | |||
204 | 5 | if (! empty($this->primers)) { |
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205 | 1 | $referencePrimer = new ReferencePrimer($this->dm, $uow); |
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206 | |||
207 | 1 | foreach ($this->primers as $fieldName => $primer) { |
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208 | 1 | $primer = is_callable($primer) ? $primer : null; |
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209 | 1 | $referencePrimer->primeReferences($this->class, [$results], $fieldName, $this->unitOfWorkHints, $primer); |
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210 | } |
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211 | } |
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212 | } |
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213 | |||
214 | 116 | return $results; |
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215 | } |
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216 | |||
217 | /** |
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218 | * Gets the ClassMetadata instance. |
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219 | */ |
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220 | public function getClass() : ClassMetadata |
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221 | { |
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222 | return $this->class; |
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223 | } |
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224 | |||
225 | public function getDocumentManager() : DocumentManager |
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226 | { |
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227 | return $this->dm; |
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228 | } |
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229 | |||
230 | /** |
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231 | * Execute the query and return its result, which must be an Iterator. |
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232 | * |
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233 | * If the query type is not expected to return an Iterator, |
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234 | * BadMethodCallException will be thrown before executing the query. |
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235 | * Otherwise, the query will be executed and UnexpectedValueException will |
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236 | * be thrown if {@link Query::execute()} does not return an Iterator. |
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237 | * |
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238 | * @see http://php.net/manual/en/iteratoraggregate.getiterator.php |
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239 | * |
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240 | * @throws BadMethodCallException If the query type would not return an Iterator. |
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241 | * @throws UnexpectedValueException If the query did not return an Iterator. |
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242 | * @throws MongoDBException |
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243 | */ |
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244 | 83 | public function getIterator() : Iterator |
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245 | { |
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246 | 83 | switch ($this->query['type']) { |
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247 | 83 | case self::TYPE_FIND: |
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248 | 6 | case self::TYPE_DISTINCT: |
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249 | 77 | break; |
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250 | |||
251 | default: |
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252 | 6 | throw new BadMethodCallException('Iterator would not be returned for query type: ' . $this->query['type']); |
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253 | } |
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254 | |||
255 | 77 | if ($this->iterator === null) { |
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256 | 77 | $result = $this->execute(); |
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257 | 77 | if (! $result instanceof Iterator) { |
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258 | throw new UnexpectedValueException('Iterator was not returned for query type: ' . $this->query['type']); |
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259 | } |
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260 | 77 | $this->iterator = $result; |
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261 | } |
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262 | |||
263 | 77 | return $this->iterator; |
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264 | } |
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265 | |||
266 | /** |
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267 | * Return the query structure. |
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268 | */ |
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269 | 14 | public function getQuery() : array |
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270 | { |
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271 | 14 | return $this->query; |
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272 | } |
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273 | |||
274 | /** |
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275 | * Execute the query and return the first result. |
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276 | * |
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277 | * @return array|object|null |
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278 | */ |
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279 | 64 | public function getSingleResult() |
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280 | { |
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281 | 64 | $clonedQuery = clone $this; |
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282 | 64 | $clonedQuery->query['limit'] = 1; |
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283 | |||
284 | 64 | return $clonedQuery->getIterator()->current() ?: null; |
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285 | } |
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286 | |||
287 | /** |
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288 | * Return the query type. |
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289 | */ |
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290 | public function getType() : int |
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291 | { |
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292 | return $this->query['type']; |
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293 | } |
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294 | |||
295 | /** |
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296 | * Sets whether or not to hydrate the documents to objects. |
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297 | */ |
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298 | public function setHydrate(bool $hydrate) : void |
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299 | { |
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300 | $this->hydrate = $hydrate; |
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301 | } |
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302 | |||
303 | /** |
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304 | * Set whether documents should be registered in UnitOfWork. If document would |
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305 | * already be managed it will be left intact and new instance returned. |
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306 | * |
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307 | * This option has no effect if hydration is disabled. |
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308 | */ |
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309 | 163 | public function setReadOnly(bool $readOnly) : void |
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310 | { |
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311 | 163 | $this->unitOfWorkHints[self::HINT_READ_ONLY] = $readOnly; |
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312 | 163 | } |
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313 | |||
314 | /** |
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315 | * Set whether to refresh hydrated documents that are already in the |
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316 | * identity map. |
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317 | * |
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318 | * This option has no effect if hydration is disabled. |
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319 | */ |
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320 | 163 | public function setRefresh(bool $refresh) : void |
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321 | { |
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322 | 163 | $this->unitOfWorkHints[self::HINT_REFRESH] = $refresh; |
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323 | 163 | } |
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324 | |||
325 | /** |
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326 | * Set to enable wrapping of resulting Iterator with CachingIterator |
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327 | */ |
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328 | 163 | public function setRewindable(bool $rewindable = true) : void |
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329 | { |
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330 | 163 | $this->rewindable = $rewindable; |
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331 | 163 | } |
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332 | |||
333 | /** |
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334 | * Execute the query and return its results as an array. |
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335 | * |
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336 | * @see IteratorAggregate::toArray() |
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337 | */ |
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338 | 11 | public function toArray() : array |
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342 | |||
343 | /** |
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344 | * Returns an array containing the specified keys and their values from the |
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345 | * query array, provided they exist and are not null. |
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346 | */ |
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347 | 121 | private function getQueryOptions(string ...$keys) : array |
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356 | |||
357 | /** |
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358 | * Decorate the cursor with caching, hydration, and priming behavior. |
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359 | * |
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360 | * Note: while this method could strictly take a MongoDB\Driver\Cursor, we |
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361 | * accept Traversable for testing purposes since Cursor cannot be mocked. |
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362 | * HydratingIterator, CachingIterator, and BaseIterator expect a Traversable |
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363 | * so this should not have any adverse effects. |
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364 | */ |
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365 | 107 | private function makeIterator(Traversable $cursor) : Iterator |
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366 | { |
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367 | 107 | if ($this->hydrate) { |
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368 | 99 | $cursor = new HydratingIterator($cursor, $this->dm->getUnitOfWork(), $this->class, $this->unitOfWorkHints); |
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369 | } |
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370 | |||
380 | |||
381 | /** |
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382 | * Returns an array with its keys renamed based on the translation map. |
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383 | * |
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384 | * @return array $rename Translation map (from => to) for renaming keys |
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385 | */ |
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386 | 112 | private function renameQueryOptions(array $options, array $rename) : array |
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407 | |||
408 | /** |
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409 | * Execute the query and return its result. |
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410 | * |
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411 | * The return value will vary based on the query type. Commands with results |
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412 | * (e.g. aggregate, inline mapReduce) may return an ArrayIterator. Other |
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413 | * commands and operations may return a status array or a boolean, depending |
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414 | * on the driver's write concern. Queries and some mapReduce commands will |
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415 | * return an Iterator. |
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416 | * |
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417 | * @return Iterator|UpdateResult|InsertOneResult|DeleteResult|array|object|int|null |
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418 | */ |
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419 | 123 | private function runQuery() |
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505 | |||
506 | 19 | private function isFirstKeyUpdateOperator() : bool |
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513 | } |
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514 |
Let’s take a look at an example:
In the above example, the authenticate() method works fine as long as you just pass instances of MyUser. However, if you now also want to pass a different implementation of User which does not have a getDisplayName() method, the code will break.
Available Fixes
Change the type-hint for the parameter:
Add an additional type-check:
Add the method to the interface: