Complex classes like Search 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 Search, and based on these observations, apply Extract Interface, too.
| 1 | <?php | ||
| 28 | class Search | ||
| 29 | { | ||
| 30 | /** | ||
| 31 | * @var int | ||
| 32 | */ | ||
| 33 | private $size; | ||
| 34 | |||
| 35 | /** | ||
| 36 | * @var int | ||
| 37 | */ | ||
| 38 | private $from; | ||
| 39 | |||
| 40 | /** | ||
| 41 | * @var string|null | ||
| 42 | */ | ||
| 43 | private $scroll; | ||
| 44 | |||
| 45 | /** | ||
| 46 | * @var array|bool|string | ||
| 47 | */ | ||
| 48 | private $source; | ||
| 49 | |||
| 50 | /** | ||
| 51 | * @var array | ||
| 52 | */ | ||
| 53 | private $fields; | ||
| 54 | |||
| 55 | /** | ||
| 56 | * @var array | ||
| 57 | */ | ||
| 58 | private $scriptFields; | ||
| 59 | |||
| 60 | /** | ||
| 61 | * @var string | ||
| 62 | */ | ||
| 63 | private $timeout; | ||
| 64 | |||
| 65 | /** | ||
| 66 | * @var string | ||
| 67 | */ | ||
| 68 | private $searchType; | ||
| 69 | |||
| 70 | /** | ||
| 71 | * @var bool | ||
| 72 | */ | ||
| 73 | private $explain; | ||
| 74 | |||
| 75 | /** | ||
| 76 | * @var array | ||
| 77 | */ | ||
| 78 | private $stats; | ||
| 79 | |||
| 80 | /** | ||
| 81 | * @var string[] | ||
| 82 | */ | ||
| 83 | private $preference; | ||
| 84 | |||
| 85 | /** | ||
| 86 | * @var float | ||
| 87 | */ | ||
| 88 | private $minScore; | ||
| 89 | |||
| 90 | /** | ||
| 91 | * @var OrderedSerializer | ||
| 92 | */ | ||
| 93 | private $serializer; | ||
| 94 | |||
| 95 | /** | ||
| 96 | * @var SearchEndpointInterface[] | ||
| 97 | */ | ||
| 98 | private $endpoints = []; | ||
| 99 | |||
| 100 | /** | ||
| 101 | * Initializes serializer. | ||
| 102 | */ | ||
| 103 | public function __construct() | ||
| 104 |     { | ||
| 105 | $this->serializer = new OrderedSerializer( | ||
| 106 | [ | ||
| 107 | new CustomReferencedNormalizer(), | ||
| 108 | new CustomNormalizer(), | ||
| 109 | ] | ||
| 110 | ); | ||
| 111 | } | ||
| 112 | |||
| 113 | /** | ||
| 114 | * Adds query to search. | ||
| 115 | * | ||
| 116 | * @param BuilderInterface $query | ||
| 117 | * @param string $boolType | ||
| 118 | * | ||
| 119 | * @return Search | ||
| 120 | */ | ||
| 121 | public function addQuery(BuilderInterface $query, $boolType = '') | ||
| 122 |     { | ||
| 123 | $this | ||
| 124 |             ->getEndpoint('query') | ||
| 125 | ->addBuilder($query, ['bool_type' => $boolType]); | ||
| 126 | |||
| 127 | return $this; | ||
| 128 | } | ||
| 129 | |||
| 130 | /** | ||
| 131 | * Sets parameters for bool query. | ||
| 132 | * | ||
| 133 | * @param array $params Example values: | ||
| 134 | * - minimum_should_match => 1 | ||
| 135 | * - boost => 1. | ||
| 136 | * | ||
| 137 | * @return Search | ||
| 138 | */ | ||
| 139 | public function setBoolQueryParameters(array $params) | ||
| 140 |     { | ||
| 141 | $this | ||
|  | |||
| 142 |             ->getEndpoint('query') | ||
| 143 | ->setParameters($params); | ||
| 144 | |||
| 145 | return $this; | ||
| 146 | } | ||
| 147 | |||
| 148 | /** | ||
| 149 | * Returns contained query. | ||
| 150 | * | ||
| 151 | * @return BuilderInterface | ||
| 152 | */ | ||
| 153 | public function getQuery() | ||
| 154 |     { | ||
| 155 | return $this | ||
| 156 |             ->getEndpoint('query') | ||
| 157 | ->getBuilder(); | ||
| 158 | } | ||
| 159 | |||
| 160 | /** | ||
| 161 | * Destroys query part. | ||
| 162 | * | ||
| 163 | * @return Search | ||
| 164 | */ | ||
| 165 | public function destroyQuery() | ||
| 166 |     { | ||
| 167 |         $this->destroyEndpoint('query'); | ||
| 168 | |||
| 169 | return $this; | ||
| 170 | } | ||
| 171 | |||
| 172 | /** | ||
| 173 | * Adds a filter to search. | ||
| 174 | * | ||
| 175 | * @param BuilderInterface $filter Filter. | ||
| 176 | * @param string $boolType Possible boolType values: | ||
| 177 | * - must | ||
| 178 | * - must_not | ||
| 179 | * - should. | ||
| 180 | * | ||
| 181 | * @return Search | ||
| 182 | */ | ||
| 183 | public function addFilter(BuilderInterface $filter, $boolType = '') | ||
| 184 |     { | ||
| 185 |         $this->getEndpoint('query'); | ||
| 186 | |||
| 187 | $this | ||
| 188 |             ->getEndpoint('filter') | ||
| 189 | ->addBuilder($filter, ['bool_type' => $boolType]); | ||
| 190 | |||
| 191 | return $this; | ||
| 192 | } | ||
| 193 | |||
| 194 | /** | ||
| 195 | * Returns currently contained filters. | ||
| 196 | * | ||
| 197 | * @return BuilderInterface | ||
| 198 | */ | ||
| 199 | public function getFilters() | ||
| 200 |     { | ||
| 201 | return $this | ||
| 202 |             ->getEndpoint('filter') | ||
| 203 | ->getBuilder(); | ||
| 204 | } | ||
| 205 | |||
| 206 | /** | ||
| 207 | * Sets bool filter parameters. | ||
| 208 | * | ||
| 209 | * @param array $params Possible values: | ||
| 210 | * _cache => true | ||
| 211 | * false. | ||
| 212 | * | ||
| 213 | * @return Search | ||
| 214 | */ | ||
| 215 | public function setBoolFilterParameters($params) | ||
| 216 |     { | ||
| 217 | $this | ||
| 218 |             ->getEndpoint('filter') | ||
| 219 | ->setParameters($params); | ||
| 220 | |||
| 221 | return $this; | ||
| 222 | } | ||
| 223 | |||
| 224 | /** | ||
| 225 | * Destroys filter part. | ||
| 226 | */ | ||
| 227 | public function destroyFilters() | ||
| 231 | |||
| 232 | /** | ||
| 233 | * Adds a post filter to search. | ||
| 234 | * | ||
| 235 | * @param BuilderInterface $postFilter Post filter. | ||
| 236 | * @param string $boolType Possible boolType values: | ||
| 237 | * - must | ||
| 238 | * - must_not | ||
| 239 | * - should. | ||
| 240 | * | ||
| 241 | * @return Search | ||
| 242 | */ | ||
| 243 | public function addPostFilter(BuilderInterface $postFilter, $boolType = '') | ||
| 244 |     { | ||
| 245 | $this | ||
| 246 |             ->getEndpoint('post_filter') | ||
| 247 | ->addBuilder($postFilter, ['bool_type' => $boolType]); | ||
| 248 | |||
| 249 | return $this; | ||
| 250 | } | ||
| 251 | |||
| 252 | /** | ||
| 253 | * Returns all contained post filters. | ||
| 254 | * | ||
| 255 | * @return BuilderInterface | ||
| 256 | */ | ||
| 257 | public function getPostFilters() | ||
| 258 |     { | ||
| 259 | return $this | ||
| 260 |             ->getEndpoint('post_filter') | ||
| 261 | ->getBuilder(); | ||
| 262 | } | ||
| 263 | |||
| 264 | /** | ||
| 265 | * Sets bool post filter parameters. | ||
| 266 | * | ||
| 267 | * @param array $params Possible values: | ||
| 268 | * _cache => true | ||
| 269 | * false. | ||
| 270 | * | ||
| 271 | * @return Search | ||
| 272 | */ | ||
| 273 | public function setBoolPostFilterParameters($params) | ||
| 274 |     { | ||
| 275 | $this | ||
| 276 |             ->getEndpoint('post_filter') | ||
| 277 | ->setParameters($params); | ||
| 278 | |||
| 279 | return $this; | ||
| 280 | } | ||
| 281 | |||
| 282 | /** | ||
| 283 | * Returns min score value. | ||
| 284 | * | ||
| 285 | * @return float | ||
| 286 | */ | ||
| 287 | public function getMinScore() | ||
| 291 | |||
| 292 | /** | ||
| 293 | * Exclude documents which have a _score less than the minimum specified. | ||
| 294 | * | ||
| 295 | * @param float $minScore | ||
| 296 | * | ||
| 297 | * @return Search | ||
| 298 | */ | ||
| 299 | public function setMinScore($minScore) | ||
| 300 |     { | ||
| 301 | $this->minScore = $minScore; | ||
| 302 | |||
| 303 | return $this; | ||
| 304 | } | ||
| 305 | |||
| 306 | /** | ||
| 307 | * Paginate results from. | ||
| 308 | * | ||
| 309 | * @param int $from | ||
| 310 | * | ||
| 311 | * @return Search | ||
| 312 | */ | ||
| 313 | public function setFrom($from) | ||
| 314 |     { | ||
| 315 | $this->from = $from; | ||
| 316 | |||
| 317 | return $this; | ||
| 318 | } | ||
| 319 | |||
| 320 | /** | ||
| 321 | * Returns results offset value. | ||
| 322 | * | ||
| 323 | * @return int | ||
| 324 | */ | ||
| 325 | public function getFrom() | ||
| 329 | |||
| 330 | /** | ||
| 331 | * Set maximum number of results. | ||
| 332 | * | ||
| 333 | * @param int $size | ||
| 334 | * | ||
| 335 | * @return Search | ||
| 336 | */ | ||
| 337 | public function setSize($size) | ||
| 338 |     { | ||
| 339 | $this->size = $size; | ||
| 340 | |||
| 341 | return $this; | ||
| 342 | } | ||
| 343 | |||
| 344 | /** | ||
| 345 | * Returns maximum number of results query can request. | ||
| 346 | * | ||
| 347 | * @return int | ||
| 348 | */ | ||
| 349 | public function getSize() | ||
| 353 | |||
| 354 | /** | ||
| 355 | * Adds sort to search. | ||
| 356 | * | ||
| 357 | * @param AbstractSort $sort | ||
| 358 | * | ||
| 359 | * @return Search | ||
| 360 | */ | ||
| 361 | public function addSort(AbstractSort $sort) | ||
| 362 |     { | ||
| 363 | $this | ||
| 364 |             ->getEndpoint('sort') | ||
| 365 | ->addBuilder($sort); | ||
| 366 | |||
| 367 | return $this; | ||
| 368 | } | ||
| 369 | |||
| 370 | /** | ||
| 371 | * Returns sorts object. | ||
| 372 | * | ||
| 373 | * @return Sorts | ||
| 374 | */ | ||
| 375 | public function getSorts() | ||
| 376 |     { | ||
| 377 | return $this | ||
| 378 |             ->getEndpoint('sort') | ||
| 379 | ->getBuilder(); | ||
| 380 | } | ||
| 381 | |||
| 382 | /** | ||
| 383 | * Allows to control how the _source field is returned with every hit. | ||
| 384 | * | ||
| 385 | * @param array|bool|string $source | ||
| 386 | * | ||
| 387 | * @return Search | ||
| 388 | */ | ||
| 389 | public function setSource($source) | ||
| 390 |     { | ||
| 391 | $this->source = $source; | ||
| 392 | |||
| 393 | return $this; | ||
| 394 | } | ||
| 395 | |||
| 396 | /** | ||
| 397 | * Returns source value. | ||
| 398 | * | ||
| 399 | * @return array|bool|string | ||
| 400 | */ | ||
| 401 | public function getSource() | ||
| 405 | |||
| 406 | /** | ||
| 407 | * Allows to selectively load specific stored fields for each document represented by a search hit. | ||
| 408 | * | ||
| 409 | * @param array $fields | ||
| 410 | * | ||
| 411 | * @return Search | ||
| 412 | */ | ||
| 413 | public function setFields(array $fields) | ||
| 414 |     { | ||
| 415 | $this->fields = $fields; | ||
| 416 | |||
| 417 | return $this; | ||
| 418 | } | ||
| 419 | |||
| 420 | /** | ||
| 421 | * Returns field value. | ||
| 422 | * | ||
| 423 | * @return array | ||
| 424 | */ | ||
| 425 | public function getFields() | ||
| 429 | |||
| 430 | /** | ||
| 431 | * Allows to return a script evaluation (based on different fields) for each hit. | ||
| 432 | * | ||
| 433 | * @param array $scriptFields | ||
| 434 | * | ||
| 435 | * @return Search | ||
| 436 | */ | ||
| 437 | public function setScriptFields($scriptFields) | ||
| 438 |     { | ||
| 439 | $this->scriptFields = $scriptFields; | ||
| 440 | |||
| 441 | return $this; | ||
| 442 | } | ||
| 443 | |||
| 444 | /** | ||
| 445 | * Returns containing script fields. | ||
| 446 | * | ||
| 447 | * @return array | ||
| 448 | */ | ||
| 449 | public function getScriptFields() | ||
| 453 | |||
| 454 | /** | ||
| 455 | * Allows to highlight search results on one or more fields. | ||
| 456 | * | ||
| 457 | * @param Highlight $highlight | ||
| 458 | * | ||
| 459 | * @return Search | ||
| 460 | */ | ||
| 461 | public function setHighlight($highlight) | ||
| 462 |     { | ||
| 463 | $this | ||
| 464 |             ->getEndpoint('highlight') | ||
| 465 | ->addBuilder($highlight); | ||
| 466 | |||
| 467 | return $this; | ||
| 468 | } | ||
| 469 | |||
| 470 | /** | ||
| 471 | * Returns containing highlight object. | ||
| 472 | * | ||
| 473 | * @return Highlight | ||
| 474 | */ | ||
| 475 | public function getHighlight() | ||
| 476 |     { | ||
| 477 | return $this | ||
| 478 |             ->getEndpoint('highlight') | ||
| 479 | ->getBuilder(); | ||
| 480 | } | ||
| 481 | |||
| 482 | /** | ||
| 483 | * Sets explain property in request body search. | ||
| 484 | * | ||
| 485 | * @param bool $explain | ||
| 486 | * | ||
| 487 | * @return Search | ||
| 488 | */ | ||
| 489 | public function setExplain($explain) | ||
| 490 |     { | ||
| 491 | $this->explain = $explain; | ||
| 492 | |||
| 493 | return $this; | ||
| 494 | } | ||
| 495 | |||
| 496 | /** | ||
| 497 | * Returns if explain property is set in request body search. | ||
| 498 | * | ||
| 499 | * @return bool | ||
| 500 | */ | ||
| 501 | public function isExplain() | ||
| 505 | |||
| 506 | /** | ||
| 507 | * Sets a stats group. | ||
| 508 | * | ||
| 509 | * @param array $stats | ||
| 510 | * | ||
| 511 | * @return Search | ||
| 512 | */ | ||
| 513 | public function setStats($stats) | ||
| 514 |     { | ||
| 515 | $this->stats = $stats; | ||
| 516 | |||
| 517 | return $this; | ||
| 518 | } | ||
| 519 | |||
| 520 | /** | ||
| 521 | * Returns a stats group. | ||
| 522 | * | ||
| 523 | * @return array | ||
| 524 | */ | ||
| 525 | public function getStats() | ||
| 529 | |||
| 530 | /** | ||
| 531 | * Adds aggregation into search. | ||
| 532 | * | ||
| 533 | * @param AbstractAggregation $aggregation | ||
| 534 | * | ||
| 535 | * @return Search | ||
| 536 | */ | ||
| 537 | public function addAggregation(AbstractAggregation $aggregation) | ||
| 538 |     { | ||
| 539 | $this | ||
| 540 |             ->getEndpoint('aggregations') | ||
| 541 | ->addBuilder($aggregation); | ||
| 542 | |||
| 543 | return $this; | ||
| 544 | } | ||
| 545 | |||
| 546 | /** | ||
| 547 | * Returns contained aggregations. | ||
| 548 | * | ||
| 549 | * @return AbstractAggregation[] | ||
| 550 | */ | ||
| 551 | public function getAggregations() | ||
| 552 |     { | ||
| 553 | return $this | ||
| 554 |             ->getEndpoint('aggregations') | ||
| 555 | ->getBuilder(); | ||
| 556 | } | ||
| 557 | |||
| 558 | /** | ||
| 559 | * Adds suggester to search. | ||
| 560 | * | ||
| 561 | * @param AbstractSuggester $suggester | ||
| 562 | * | ||
| 563 | * @return Search | ||
| 564 | */ | ||
| 565 | public function addSuggester(AbstractSuggester $suggester) | ||
| 566 |     { | ||
| 567 | $this | ||
| 568 |             ->getEndpoint('suggest') | ||
| 569 | ->addBuilder($suggester); | ||
| 570 | |||
| 571 | return $this; | ||
| 572 | } | ||
| 573 | |||
| 574 | /** | ||
| 575 | * Returns all contained suggester's. | ||
| 576 | * | ||
| 577 | * @return AbstractSuggester[] | ||
| 578 | */ | ||
| 579 | public function getSuggesters() | ||
| 580 |     { | ||
| 581 | return $this | ||
| 582 |             ->getEndpoint('suggest') | ||
| 583 | ->getBuilder(); | ||
| 584 | } | ||
| 585 | |||
| 586 | /** | ||
| 587 | * Setter for scroll duration, effectively setting if search is scrolled or not. | ||
| 588 | * | ||
| 589 | * @param string|null $duration | ||
| 590 | * | ||
| 591 | * @return Search | ||
| 592 | */ | ||
| 593 | public function setScroll($duration = '5m') | ||
| 594 |     { | ||
| 595 | $this->scroll = $duration; | ||
| 596 | |||
| 597 | return $this; | ||
| 598 | } | ||
| 599 | |||
| 600 | /** | ||
| 601 | * Returns scroll duration. | ||
| 602 | * | ||
| 603 | * @return string|null | ||
| 604 | */ | ||
| 605 | public function getScroll() | ||
| 609 | |||
| 610 | /** | ||
| 611 | * Set search type. | ||
| 612 | * | ||
| 613 | * @param string $searchType | ||
| 614 | * | ||
| 615 | * @return Search | ||
| 616 | */ | ||
| 617 | public function setSearchType($searchType) | ||
| 618 |     { | ||
| 619 | $this->searchType = $searchType; | ||
| 620 | |||
| 621 | return $this; | ||
| 622 | } | ||
| 623 | |||
| 624 | /** | ||
| 625 | * Returns search type used. | ||
| 626 | * | ||
| 627 | * @return string | ||
| 628 | */ | ||
| 629 | public function getSearchType() | ||
| 633 | |||
| 634 | /** | ||
| 635 | * @return int | ||
| 636 | */ | ||
| 637 | public function getTimeout() | ||
| 641 | |||
| 642 | /** | ||
| 643 | * @param int $timeout | ||
| 644 | */ | ||
| 645 | public function setTimeout($timeout) | ||
| 649 | |||
| 650 | /** | ||
| 651 | * Setter for preference. | ||
| 652 | * | ||
| 653 | * Controls which shard replicas to execute the search request on. | ||
| 654 | * | ||
| 655 | * @param mixed $preferenceParams Possible values: | ||
| 656 | * _primary | ||
| 657 | * _primary_first | ||
| 658 | * _local | ||
| 659 | * _only_node:xyz (xyz - node id) | ||
| 660 | * _prefer_node:xyz (xyz - node id) | ||
| 661 | * _shards:2,3 (2 and 3 specified shards) | ||
| 662 | * custom value | ||
| 663 | * string[] combination of params. | ||
| 664 | * | ||
| 665 | * @return Search | ||
| 666 | */ | ||
| 667 | public function setPreference($preferenceParams) | ||
| 679 | |||
| 680 | /** | ||
| 681 | * Returns preference params as string. | ||
| 682 | * | ||
| 683 | * @return string | ||
| 684 | */ | ||
| 685 | public function getPreference() | ||
| 689 | |||
| 690 | /** | ||
| 691 | * Returns query url parameters. | ||
| 692 | * | ||
| 693 | * @return array | ||
| 694 | */ | ||
| 695 | public function getQueryParams() | ||
| 696 |     { | ||
| 697 | return array_filter( | ||
| 698 | [ | ||
| 699 | 'scroll' => $this->getScroll(), | ||
| 700 | 'timeout' => $this->getTimeout(), | ||
| 701 | 'search_type' => $this->getSearchType(), | ||
| 702 | 'preference' => $this->getPreference(), | ||
| 703 | ] | ||
| 704 | ); | ||
| 705 | } | ||
| 706 | |||
| 707 | /** | ||
| 708 |      * {@inheritdoc} | ||
| 709 | */ | ||
| 710 | public function toArray() | ||
| 711 |     { | ||
| 712 | $output = array_filter($this->serializer->normalize($this->endpoints)); | ||
| 713 | |||
| 714 | $params = [ | ||
| 715 | 'from' => 'from', | ||
| 716 | 'size' => 'size', | ||
| 717 | 'fields' => 'fields', | ||
| 718 | 'scriptFields' => 'script_fields', | ||
| 719 | 'explain' => 'explain', | ||
| 720 | 'stats' => 'stats', | ||
| 721 | 'minScore' => 'min_score', | ||
| 722 | 'source' => '_source', | ||
| 723 | ]; | ||
| 724 | |||
| 725 |         foreach ($params as $field => $param) { | ||
| 726 |             if ($this->$field !== null) { | ||
| 727 | $output[$param] = $this->$field; | ||
| 728 | } | ||
| 729 | } | ||
| 730 | |||
| 731 | return $output; | ||
| 732 | } | ||
| 733 | |||
| 734 | /** | ||
| 735 | * Returns endpoint instance. | ||
| 736 | * | ||
| 737 | * @param string $type Endpoint type. | ||
| 738 | * | ||
| 739 | * @return SearchEndpointInterface | ||
| 740 | */ | ||
| 741 | private function getEndpoint($type) | ||
| 742 |     { | ||
| 743 |         if (!array_key_exists($type, $this->endpoints)) { | ||
| 744 | $this->endpoints[$type] = SearchEndpointFactory::get($type); | ||
| 745 | } | ||
| 746 | |||
| 747 | return $this->endpoints[$type]; | ||
| 748 | } | ||
| 749 | |||
| 750 | /** | ||
| 751 | * Destroys search endpoint. | ||
| 752 | * | ||
| 753 | * @param string $type Endpoint type. | ||
| 754 | */ | ||
| 755 | private function destroyEndpoint($type) | ||
| 759 | } | ||
| 760 | 
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: