Complex classes like Collection 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 Collection, and based on these observations, apply Extract Interface, too.
| 1 | <?php |
||
| 16 | class Collection implements CollectionContract { |
||
| 17 | |||
| 18 | /** |
||
| 19 | * Collection elements. |
||
| 20 | * |
||
| 21 | * @var array |
||
| 22 | */ |
||
| 23 | protected $elements = array(); |
||
| 24 | |||
| 25 | /** |
||
| 26 | * Collection type to enforce. |
||
| 27 | * |
||
| 28 | * @var Type |
||
| 29 | */ |
||
| 30 | private $type; |
||
| 31 | |||
| 32 | /** |
||
| 33 | * Where Collection is in loop. |
||
| 34 | * |
||
| 35 | * @var int |
||
| 36 | */ |
||
| 37 | protected $position = 0; |
||
| 38 | |||
| 39 | /** |
||
| 40 | * Collection constructor. |
||
| 41 | * |
||
| 42 | * @param string $type |
||
| 43 | * @param array $elements |
||
| 44 | */ |
||
| 45 | 57 | public function __construct( $type, array $elements = array() ) { |
|
| 62 | |||
| 63 | /** |
||
| 64 | * {@inheritdoc} |
||
| 65 | * |
||
| 66 | * @return string |
||
| 67 | */ |
||
| 68 | 12 | public function get_type() { |
|
| 71 | |||
| 72 | /** |
||
| 73 | * {@inheritdoc} |
||
| 74 | * |
||
| 75 | * @param mixed $element |
||
| 76 | * |
||
| 77 | * @return Collection |
||
| 78 | * |
||
| 79 | * @throws InvalidArgumentException |
||
| 80 | */ |
||
| 81 | 12 | public function add( $element ) { |
|
| 96 | |||
| 97 | /** |
||
| 98 | * {@inheritdoc} |
||
| 99 | * |
||
| 100 | * @return Collection |
||
| 101 | */ |
||
| 102 | public function clear() { |
||
| 105 | |||
| 106 | /** |
||
| 107 | * {@inheritdoc} |
||
| 108 | * |
||
| 109 | * @param callable $condition Condition to satisfy. |
||
| 110 | * |
||
| 111 | * @return bool |
||
| 112 | */ |
||
| 113 | public function contains( callable $condition ) { |
||
| 116 | |||
| 117 | /** |
||
| 118 | * {@inheritdoc} |
||
| 119 | * |
||
| 120 | * @param callable $condition Condition to satisfy. |
||
| 121 | * |
||
| 122 | * @return mixed |
||
| 123 | */ |
||
| 124 | public function find( callable $condition ) { |
||
| 129 | |||
| 130 | /** |
||
| 131 | * {@inheritdoc} |
||
| 132 | * |
||
| 133 | * @param callable $condition Condition to satisfy. |
||
| 134 | * |
||
| 135 | * @return int |
||
| 136 | */ |
||
| 137 | public function find_index( callable $condition ) { |
||
| 149 | |||
| 150 | /** |
||
| 151 | * Fetches the element at the provided index. |
||
| 152 | * |
||
| 153 | * @param int $index Index to get element from. |
||
| 154 | * |
||
| 155 | * @return mixed |
||
| 156 | * |
||
| 157 | * @throws OutOfRangeException |
||
| 158 | */ |
||
| 159 | 12 | public function at( $index ) { |
|
| 164 | |||
| 165 | /** |
||
| 166 | * {@inheritdoc} |
||
| 167 | * |
||
| 168 | * @param int $index Index to check for existence. |
||
| 169 | * |
||
| 170 | * @return bool |
||
| 171 | * |
||
| 172 | * @throws InvalidArgumentException |
||
| 173 | */ |
||
| 174 | 12 | public function index_exists( $index ) { |
|
| 185 | |||
| 186 | /** |
||
| 187 | * {@inheritdoc} |
||
| 188 | * |
||
| 189 | * @param callable $condition Condition to satisfy. |
||
| 190 | * |
||
| 191 | * @return mixed |
||
| 192 | */ |
||
| 193 | public function filter( callable $condition ) { |
||
| 204 | /** |
||
| 205 | * {@inheritdoc} |
||
| 206 | * |
||
| 207 | * @param callable $condition Condition to satisfy. |
||
| 208 | * |
||
| 209 | * @return mixed |
||
| 210 | */ |
||
| 211 | public function find_last( callable $condition ) { |
||
| 216 | |||
| 217 | /** |
||
| 218 | * {@inheritdoc} |
||
| 219 | * |
||
| 220 | * @param callable $condition |
||
| 221 | * @return int |
||
| 222 | */ |
||
| 223 | public function find_last_index( callable $condition ) { |
||
| 235 | |||
| 236 | /** |
||
| 237 | * {@inheritdoc} |
||
| 238 | * |
||
| 239 | * @param int $start Begining index to slice from. |
||
| 240 | * @param int $end End index to slice to. |
||
| 241 | * |
||
| 242 | * @return Collection |
||
| 243 | * |
||
| 244 | * @throws InvalidArgumentException |
||
| 245 | */ |
||
| 246 | public function slice( $start, $end ) { |
||
| 271 | |||
| 272 | /** |
||
| 273 | * {@inheritdoc} |
||
| 274 | * |
||
| 275 | * @param int $index Index to start at. |
||
| 276 | * @param mixed $element Element to insert. |
||
| 277 | * |
||
| 278 | * @return Collection |
||
| 279 | * |
||
| 280 | * @throws InvalidArgumentException |
||
| 281 | * @throws OutOfRangeException |
||
| 282 | */ |
||
| 283 | public function insert( $index, $element ) { |
||
| 294 | |||
| 295 | /** |
||
| 296 | * {@inheritdoc} |
||
| 297 | * |
||
| 298 | * @param int $index Index to start insertion at. |
||
| 299 | * @param array $elements Elements in insert. |
||
| 300 | * |
||
| 301 | * @return Collection |
||
| 302 | * |
||
| 303 | * @throws OutOfRangeException |
||
| 304 | */ |
||
| 305 | public function insert_range( $index, array $elements ) { |
||
| 323 | |||
| 324 | /** |
||
| 325 | * {@inheritdoc} |
||
| 326 | * |
||
| 327 | * @param callable $condition Condition to satisfy. |
||
| 328 | * |
||
| 329 | * @return Collection |
||
| 330 | */ |
||
| 331 | public function without( callable $condition ) { |
||
| 338 | |||
| 339 | /** |
||
| 340 | * {@inheritdoc} |
||
| 341 | * |
||
| 342 | * @param int $index Index to remove. |
||
| 343 | * |
||
| 344 | * @return Collection |
||
| 345 | * |
||
| 346 | * @throws OutOfRangeException |
||
| 347 | */ |
||
| 348 | public function remove_at( $index ) { |
||
| 360 | /** |
||
| 361 | * {@inheritdoc} |
||
| 362 | * |
||
| 363 | * @return Collection |
||
| 364 | */ |
||
| 365 | public function reverse() { |
||
| 370 | |||
| 371 | /** |
||
| 372 | * {@inheritdoc} |
||
| 373 | * |
||
| 374 | * @param callable $callback Sort callback. |
||
| 375 | * |
||
| 376 | * @return Collection |
||
| 377 | */ |
||
| 378 | public function sort( callable $callback ) { |
||
| 383 | |||
| 384 | /** |
||
| 385 | * {@inheritdoc} |
||
| 386 | * |
||
| 387 | * @return array |
||
| 388 | */ |
||
| 389 | 9 | public function to_array() { |
|
| 392 | |||
| 393 | /** |
||
| 394 | * {@inheritdoc} |
||
| 395 | * |
||
| 396 | * @param callable $callable Reducer function. |
||
| 397 | * |
||
| 398 | * @param null $initial Initial reducer value. |
||
| 399 | * |
||
| 400 | * @return mixed |
||
| 401 | */ |
||
| 402 | public function reduce( callable $callable, $initial = null ) { |
||
| 405 | |||
| 406 | /** |
||
| 407 | * {@inheritdoc} |
||
| 408 | * |
||
| 409 | * @param callable $condition Condition callback. |
||
| 410 | * |
||
| 411 | * @return bool |
||
| 412 | */ |
||
| 413 | public function every( callable $condition ) { |
||
| 427 | |||
| 428 | /** |
||
| 429 | * {@inheritdoc} |
||
| 430 | * |
||
| 431 | * @param int $num Number of elements to drop. |
||
| 432 | * |
||
| 433 | * @return Collection |
||
| 434 | * |
||
| 435 | * @throws InvalidArgumentException |
||
| 436 | */ |
||
| 437 | public function drop( $num ) { |
||
| 440 | |||
| 441 | /** |
||
| 442 | * {@inheritdoc} |
||
| 443 | * |
||
| 444 | * @param int $num Number of elements to drop. |
||
| 445 | * |
||
| 446 | * @return Collection |
||
| 447 | * |
||
| 448 | * @throws InvalidArgumentException |
||
| 449 | */ |
||
| 450 | public function drop_right( $num ) { |
||
| 455 | |||
| 456 | /** |
||
| 457 | * {@inheritdoc} |
||
| 458 | * |
||
| 459 | * @param callable $condition Condition callback. |
||
| 460 | * |
||
| 461 | * @return Collection |
||
| 462 | */ |
||
| 463 | public function drop_while( callable $condition ) { |
||
| 467 | /** |
||
| 468 | * {@inheritdoc} |
||
| 469 | * |
||
| 470 | * @return Collection |
||
| 471 | * |
||
| 472 | * @throws InvalidArgumentException |
||
| 473 | */ |
||
| 474 | public function tail() { |
||
| 477 | |||
| 478 | /** |
||
| 479 | * {@inheritdoc} |
||
| 480 | * |
||
| 481 | * @param int $num Number of elements to take. |
||
| 482 | * |
||
| 483 | * @return Collection |
||
| 484 | * |
||
| 485 | * @throws InvalidArgumentException |
||
| 486 | */ |
||
| 487 | public function take( $num ) { |
||
| 490 | |||
| 491 | /** |
||
| 492 | * {@inheritdoc} |
||
| 493 | * |
||
| 494 | * @param int $num Number of elements to take. |
||
| 495 | * |
||
| 496 | * @return Collection |
||
| 497 | * |
||
| 498 | * @throws InvalidArgumentException |
||
| 499 | */ |
||
| 500 | public function take_right( $num ) { |
||
| 503 | |||
| 504 | /** |
||
| 505 | * {@inheritdoc} |
||
| 506 | * |
||
| 507 | * @param callable $condition Callback function. |
||
| 508 | * |
||
| 509 | * @return Collection |
||
| 510 | */ |
||
| 511 | public function take_while( callable $condition ) { |
||
| 516 | |||
| 517 | /** |
||
| 518 | * {@inheritdoc} |
||
| 519 | * |
||
| 520 | * @param callable $callable Callback function. |
||
| 521 | */ |
||
| 522 | public function each( callable $callable ) { |
||
| 527 | |||
| 528 | /** |
||
| 529 | * {@inheritdoc} |
||
| 530 | * |
||
| 531 | * @param callable $callable Callback function. |
||
| 532 | * |
||
| 533 | * @return Collection |
||
| 534 | */ |
||
| 535 | 9 | public function map( callable $callable ) { |
|
| 554 | |||
| 555 | /** |
||
| 556 | * {@inheritdoc} |
||
| 557 | * |
||
| 558 | * @param callable $callable Reducer function. |
||
| 559 | * @param null $initial Initial value. |
||
| 560 | * |
||
| 561 | * @return mixed |
||
| 562 | */ |
||
| 563 | public function reduce_right( callable $callable, $initial = null ) { |
||
| 570 | |||
| 571 | /** |
||
| 572 | * {@inheritdoc} |
||
| 573 | * |
||
| 574 | * @return Collection |
||
| 575 | */ |
||
| 576 | public function shuffle() { |
||
| 582 | |||
| 583 | /** |
||
| 584 | * {@inheritdoc} |
||
| 585 | * |
||
| 586 | * @param array|Collection $elements Array of elements to merge. |
||
| 587 | * |
||
| 588 | * @return Collection |
||
| 589 | * |
||
| 590 | * @throws InvalidArgumentException |
||
| 591 | */ |
||
| 592 | public function merge( $elements ) { |
||
| 607 | |||
| 608 | /** |
||
| 609 | * {@inheritdoc} |
||
| 610 | * |
||
| 611 | * @return mixed |
||
| 612 | * |
||
| 613 | * @throws OutOfBoundsException |
||
| 614 | */ |
||
| 615 | public function first() { |
||
| 622 | |||
| 623 | /** |
||
| 624 | * {@inheritdoc} |
||
| 625 | * |
||
| 626 | * @return mixed |
||
| 627 | * |
||
| 628 | * @throws OutOfBoundsException |
||
| 629 | */ |
||
| 630 | public function last() { |
||
| 637 | |||
| 638 | /** |
||
| 639 | * {@inheritdoc} |
||
| 640 | * |
||
| 641 | * @return int |
||
| 642 | */ |
||
| 643 | 18 | public function count() { |
|
| 646 | |||
| 647 | /** |
||
| 648 | * {@inheritDoc} |
||
| 649 | * |
||
| 650 | * @return array |
||
| 651 | */ |
||
| 652 | public function serialize() { |
||
| 661 | |||
| 662 | /** |
||
| 663 | * Return the current element. |
||
| 664 | * |
||
| 665 | * @return mixed |
||
| 666 | */ |
||
| 667 | 3 | public function current() { |
|
| 670 | |||
| 671 | /** |
||
| 672 | * Move forward to next element. |
||
| 673 | */ |
||
| 674 | 3 | public function next() { |
|
| 677 | |||
| 678 | /** |
||
| 679 | * Return the key of the current element. |
||
| 680 | * |
||
| 681 | * @return mixed |
||
| 682 | */ |
||
| 683 | 3 | public function key() { |
|
| 686 | |||
| 687 | /** |
||
| 688 | * Checks if current position is valid. |
||
| 689 | * |
||
| 690 | * @return bool |
||
| 691 | */ |
||
| 692 | 3 | public function valid() { |
|
| 695 | |||
| 696 | /** |
||
| 697 | * Rewind the Iterator to the first element. |
||
| 698 | */ |
||
| 699 | 3 | public function rewind() { |
|
| 702 | |||
| 703 | /** |
||
| 704 | * Creates a new instance of the Collection |
||
| 705 | * from a trusted set of elements. |
||
| 706 | * |
||
| 707 | * @param array $elements Array of elements to pass into new collection. |
||
| 708 | * @param null|mixed $type |
||
| 709 | * |
||
| 710 | * @return static |
||
| 711 | */ |
||
| 712 | 9 | protected function new_from_trusted( array $elements, $type = null ) { |
|
| 718 | |||
| 719 | /** |
||
| 720 | * Sets the elements without validating them. |
||
| 721 | * |
||
| 722 | * @param array $elements Pre-validated elements to set. |
||
| 723 | */ |
||
| 724 | 18 | protected function set_from_trusted( array $elements ) { |
|
| 727 | |||
| 728 | /** |
||
| 729 | * Number of elements true for the condition. |
||
| 730 | * |
||
| 731 | * @param callable $condition Condition to check. |
||
| 732 | * @return int |
||
| 733 | */ |
||
| 734 | protected function count_while_true( callable $condition ) { |
||
| 746 | |||
| 747 | /** |
||
| 748 | * Validates a number to be used as an index. |
||
| 749 | * |
||
| 750 | * @param integer $index The number to be validated as an index. |
||
| 751 | * |
||
| 752 | * @throws OutOfRangeException |
||
| 753 | */ |
||
| 754 | 12 | protected function validate_index( $index ) { |
|
| 761 | } |
||
| 762 |
It seems like the type of the argument is not accepted by the function/method which you are calling.
In some cases, in particular if PHP’s automatic type-juggling kicks in this might be fine. In other cases, however this might be a bug.
We suggest to add an explicit type cast like in the following example: