Complex classes like Container 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 Container, and based on these observations, apply Extract Interface, too.
| 1 | <?php |
||
| 15 | class Container implements ContainerInterface { |
||
| 16 | private $currentRule; |
||
| 17 | private $currentRuleName; |
||
| 18 | private $instances; |
||
| 19 | private $rules; |
||
| 20 | private $factories; |
||
| 21 | |||
| 22 | /** |
||
| 23 | * Construct a new instance of the {@link Container} class. |
||
| 24 | */ |
||
| 25 | 89 | public function __construct() { |
|
| 32 | |||
| 33 | /** |
||
| 34 | * Deep clone rules. |
||
| 35 | */ |
||
| 36 | 1 | public function __clone() { |
|
| 40 | |||
| 41 | /** |
||
| 42 | * Clear all instances |
||
| 43 | * |
||
| 44 | */ |
||
| 45 | 1 | public function clearInstances() { |
|
| 48 | |||
| 49 | /** |
||
| 50 | * Deep clone an array. |
||
| 51 | * |
||
| 52 | * @param array $array The array to clone. |
||
| 53 | * @return array Returns the cloned array. |
||
| 54 | * @see http://stackoverflow.com/a/17729234 |
||
| 55 | */ |
||
| 56 | private function arrayClone(array $array) { |
||
| 57 | 1 | return array_map(function ($element) { |
|
| 58 | 1 | return ((is_array($element)) |
|
| 59 | 1 | ? $this->arrayClone($element) |
|
| 60 | 1 | : ((is_object($element)) |
|
| 61 | ? clone $element |
||
| 62 | 1 | : $element |
|
| 63 | ) |
||
| 64 | ); |
||
| 65 | 1 | }, $array); |
|
| 66 | } |
||
| 67 | |||
| 68 | /** |
||
| 69 | * Normalize a container entry ID. |
||
| 70 | * |
||
| 71 | * @param string $id The ID to normalize. |
||
| 72 | * @return string Returns a normalized ID as a string. |
||
| 73 | */ |
||
| 74 | 90 | private function normalizeID($id) { |
|
| 77 | |||
| 78 | /** |
||
| 79 | * Set the current rule to the default rule. |
||
| 80 | * |
||
| 81 | * @return $this |
||
| 82 | */ |
||
| 83 | 1 | public function defaultRule() { |
|
| 86 | |||
| 87 | /** |
||
| 88 | * Set the current rule. |
||
| 89 | * |
||
| 90 | * @param string $id The ID of the rule. |
||
| 91 | * @return $this |
||
| 92 | */ |
||
| 93 | 89 | public function rule($id) { |
|
| 104 | |||
| 105 | /** |
||
| 106 | * Get the class name of the current rule. |
||
| 107 | * |
||
| 108 | * @return string Returns a class name. |
||
| 109 | */ |
||
| 110 | 2 | public function getClass() { |
|
| 113 | |||
| 114 | /** |
||
| 115 | * Set the name of the class for the current rule. |
||
| 116 | * |
||
| 117 | * @param string $className A valid class name. |
||
| 118 | * @return $this |
||
| 119 | */ |
||
| 120 | 8 | public function setClass($className) { |
|
| 124 | |||
| 125 | /** |
||
| 126 | * Get the rule that the current rule references. |
||
| 127 | * |
||
| 128 | * @return string Returns a reference name or an empty string if there is no reference. |
||
| 129 | */ |
||
| 130 | 3 | public function getAliasOf() { |
|
| 133 | |||
| 134 | /** |
||
| 135 | * Set the rule that the current rule is an alias of. |
||
| 136 | * |
||
| 137 | * @param string $alias The name of an entry in the container to point to. |
||
| 138 | * @return $this |
||
| 139 | */ |
||
| 140 | 4 | public function setAliasOf($alias) { |
|
| 150 | |||
| 151 | /** |
||
| 152 | * Add an alias of the current rule. |
||
| 153 | * |
||
| 154 | * Setting an alias to the current rule means that getting an item with the alias' name will be like getting the item |
||
| 155 | * with the current rule. If the current rule is shared then the same shared instance will be returned. You can add |
||
| 156 | * multiple aliases by passing additional arguments to this method. |
||
| 157 | * |
||
| 158 | * If {@link Container::addAlias()} is called with an alias that is the same as the current rule then an **E_USER_NOTICE** |
||
| 159 | * level error is raised and the alias is not added. |
||
| 160 | * |
||
| 161 | * @param string ...$alias The alias to set. |
||
| 162 | * @return $this |
||
| 163 | * @since 1.4 Added the ability to pass multiple aliases. |
||
| 164 | */ |
||
|
|
|||
| 165 | 8 | public function addAlias(...$alias) { |
|
| 177 | |||
| 178 | /** |
||
| 179 | * Remove an alias of the current rule. |
||
| 180 | * |
||
| 181 | * If {@link Container::removeAlias()} is called with an alias that references a different rule then an **E_USER_NOTICE** |
||
| 182 | * level error is raised, but the alias is still removed. |
||
| 183 | * |
||
| 184 | * @param string $alias The alias to remove. |
||
| 185 | * @return $this |
||
| 186 | */ |
||
| 187 | 2 | public function removeAlias($alias) { |
|
| 197 | |||
| 198 | /** |
||
| 199 | * Get all of the aliases of the current rule. |
||
| 200 | * |
||
| 201 | * This method is intended to aid in debugging and should not be used in production as it walks the entire rule array. |
||
| 202 | * |
||
| 203 | * @return array Returns an array of strings representing aliases. |
||
| 204 | */ |
||
| 205 | 6 | public function getAliases() { |
|
| 216 | |||
| 217 | /** |
||
| 218 | * Get the factory callback for the current rule. |
||
| 219 | * |
||
| 220 | * @return callable|null Returns the rule's factory or **null** if it has none. |
||
| 221 | */ |
||
| 222 | 2 | public function getFactory() { |
|
| 225 | |||
| 226 | /** |
||
| 227 | * Set the factory that will be used to create the instance for the current rule. |
||
| 228 | * |
||
| 229 | * @param callable|null $factory This callback will be called to create the instance for the rule. |
||
| 230 | * @return $this |
||
| 231 | */ |
||
| 232 | 10 | public function setFactory(callable $factory = null) { |
|
| 236 | |||
| 237 | /** |
||
| 238 | * Whether or not the current rule is shared. |
||
| 239 | * |
||
| 240 | * @return bool Returns **true** if the rule is shared or **false** otherwise. |
||
| 241 | */ |
||
| 242 | 2 | public function isShared() { |
|
| 245 | |||
| 246 | /** |
||
| 247 | * Set whether or not the current rule is shared. |
||
| 248 | * |
||
| 249 | * @param bool $shared Whether or not the current rule is shared. |
||
| 250 | * @return $this |
||
| 251 | */ |
||
| 252 | 38 | public function setShared($shared) { |
|
| 256 | |||
| 257 | /** |
||
| 258 | * Whether or not the current rule will inherit to subclasses. |
||
| 259 | * |
||
| 260 | * @return bool Returns **true** if the current rule inherits or **false** otherwise. |
||
| 261 | */ |
||
| 262 | 2 | public function getInherit() { |
|
| 265 | |||
| 266 | /** |
||
| 267 | * Set whether or not the current rule extends to subclasses. |
||
| 268 | * |
||
| 269 | * @param bool $inherit Pass **true** to have subclasses inherit this rule or **false** otherwise. |
||
| 270 | * @return $this |
||
| 271 | */ |
||
| 272 | 3 | public function setInherit($inherit) { |
|
| 276 | |||
| 277 | /** |
||
| 278 | * Get the constructor arguments for the current rule. |
||
| 279 | * |
||
| 280 | * @return array Returns the constructor arguments for the current rule. |
||
| 281 | */ |
||
| 282 | 2 | public function getConstructorArgs() { |
|
| 285 | |||
| 286 | /** |
||
| 287 | * Set the constructor arguments for the current rule. |
||
| 288 | * |
||
| 289 | * @param array $args An array of constructor arguments. |
||
| 290 | * @return $this |
||
| 291 | */ |
||
| 292 | 25 | public function setConstructorArgs(array $args) { |
|
| 296 | |||
| 297 | /** |
||
| 298 | * Set a specific shared instance into the container. |
||
| 299 | * |
||
| 300 | * When you set an instance into the container then it will always be returned by subsequent retrievals, even if a |
||
| 301 | * rule is configured that says that instances should not be shared. |
||
| 302 | * |
||
| 303 | * @param string $name The name of the container entry. |
||
| 304 | * @param mixed $instance This instance. |
||
| 305 | * @return $this |
||
| 306 | */ |
||
| 307 | 9 | public function setInstance($name, $instance) { |
|
| 311 | |||
| 312 | /** |
||
| 313 | * Add a method call to a rule. |
||
| 314 | * |
||
| 315 | * @param string $method The name of the method to call. |
||
| 316 | * @param array $args The arguments to pass to the method. |
||
| 317 | * @return $this |
||
| 318 | */ |
||
| 319 | 8 | public function addCall($method, array $args = []) { |
|
| 324 | |||
| 325 | /** |
||
| 326 | * Finds an entry of the container by its identifier and returns it. |
||
| 327 | * |
||
| 328 | * @param string $id Identifier of the entry to look for. |
||
| 329 | * @param array $args Additional arguments to pass to the constructor. |
||
| 330 | * |
||
| 331 | * @throws NotFoundException No entry was found for this identifier. |
||
| 332 | * @throws ContainerException Error while retrieving the entry. |
||
| 333 | * |
||
| 334 | * @return mixed Entry. |
||
| 335 | */ |
||
| 336 | 70 | public function getArgs($id, array $args = []) { |
|
| 358 | |||
| 359 | /** |
||
| 360 | * Make a rule based on an ID. |
||
| 361 | * |
||
| 362 | * @param string $nid A normalized ID. |
||
| 363 | * @return array Returns an array representing a rule. |
||
| 364 | */ |
||
| 365 | 66 | private function makeRule($nid) { |
|
| 415 | |||
| 416 | /** |
||
| 417 | * Make a function that creates objects from a rule. |
||
| 418 | * |
||
| 419 | * @param string $nid The normalized ID of the container item. |
||
| 420 | * @param array $rule The resolved rule for the ID. |
||
| 421 | * @return \Closure Returns a function that when called will create a new instance of the class. |
||
| 422 | * @throws NotFoundException No entry was found for this identifier. |
||
| 423 | */ |
||
| 424 | 44 | private function makeFactory($nid, array $rule) { |
|
| 425 | 44 | $className = empty($rule['class']) ? $nid : $rule['class']; |
|
| 426 | |||
| 427 | 44 | if (!empty($rule['factory'])) { |
|
| 428 | // The instance is created with a user-supplied factory function. |
||
| 429 | 6 | $callback = $rule['factory']; |
|
| 430 | 6 | $function = $this->reflectCallback($callback); |
|
| 431 | |||
| 432 | 6 | if ($function->getNumberOfParameters() > 0) { |
|
| 433 | 3 | $callbackArgs = $this->makeDefaultArgs($function, (array)$rule['constructorArgs'], $rule); |
|
| 434 | 3 | $factory = function ($args) use ($callback, $callbackArgs) { |
|
| 435 | 3 | return call_user_func_array($callback, $this->resolveArgs($callbackArgs, $args)); |
|
| 436 | 3 | }; |
|
| 437 | } else { |
||
| 438 | 3 | $factory = $callback; |
|
| 439 | } |
||
| 440 | |||
| 441 | // If a class is specified then still reflect on it so that calls can be made against it. |
||
| 442 | 6 | if (class_exists($className)) { |
|
| 443 | 6 | $class = new \ReflectionClass($className); |
|
| 444 | } |
||
| 445 | } else { |
||
| 446 | // The instance is created by newing up a class. |
||
| 447 | 38 | if (!class_exists($className)) { |
|
| 448 | 1 | throw new NotFoundException("Class $className does not exist.", 404); |
|
| 449 | } |
||
| 450 | 37 | $class = new \ReflectionClass($className); |
|
| 451 | 37 | $constructor = $class->getConstructor(); |
|
| 452 | |||
| 453 | 37 | if ($constructor && $constructor->getNumberOfParameters() > 0) { |
|
| 454 | 34 | $constructorArgs = $this->makeDefaultArgs($constructor, (array)$rule['constructorArgs'], $rule); |
|
| 455 | |||
| 456 | 34 | $factory = function ($args) use ($className, $constructorArgs) { |
|
| 457 | 34 | return new $className(...array_values($this->resolveArgs($constructorArgs, $args))); |
|
| 458 | 34 | }; |
|
| 459 | } else { |
||
| 460 | 4 | $factory = function () use ($className) { |
|
| 461 | 4 | return new $className; |
|
| 462 | 4 | }; |
|
| 463 | } |
||
| 464 | } |
||
| 465 | |||
| 466 | // Add calls to the factory. |
||
| 467 | 43 | if (isset($class) && !empty($rule['calls'])) { |
|
| 468 | 4 | $calls = []; |
|
| 469 | |||
| 470 | // Generate the calls array. |
||
| 471 | 4 | foreach ($rule['calls'] as $call) { |
|
| 472 | 4 | list($methodName, $args) = $call; |
|
| 473 | 4 | $method = $class->getMethod($methodName); |
|
| 474 | 4 | $calls[] = [$methodName, $this->makeDefaultArgs($method, $args, $rule)]; |
|
| 475 | } |
||
| 476 | |||
| 477 | // Wrap the factory in one that makes the calls. |
||
| 478 | 4 | $factory = function ($args) use ($factory, $calls) { |
|
| 479 | 4 | $instance = $factory($args); |
|
| 480 | |||
| 481 | 4 | foreach ($calls as $call) { |
|
| 482 | 4 | call_user_func_array( |
|
| 483 | 4 | [$instance, $call[0]], |
|
| 484 | 4 | $this->resolveArgs($call[1], [], $instance) |
|
| 485 | ); |
||
| 486 | } |
||
| 487 | |||
| 488 | 4 | return $instance; |
|
| 489 | 4 | }; |
|
| 490 | } |
||
| 491 | |||
| 492 | 43 | return $factory; |
|
| 493 | } |
||
| 494 | |||
| 495 | /** |
||
| 496 | * Create a shared instance of a class from a rule. |
||
| 497 | * |
||
| 498 | * This method has the side effect of adding the new instance to the internal instances array of this object. |
||
| 499 | * |
||
| 500 | * @param string $nid The normalized ID of the container item. |
||
| 501 | * @param array $rule The resolved rule for the ID. |
||
| 502 | * @param array $args Additional arguments passed during creation. |
||
| 503 | * @return object Returns the the new instance. |
||
| 504 | * @throws NotFoundException Throws an exception if the class does not exist. |
||
| 505 | */ |
||
| 506 | 24 | private function createSharedInstance($nid, array $rule, array $args) { |
|
| 507 | 24 | if (!empty($rule['factory'])) { |
|
| 508 | // The instance is created with a user-supplied factory function. |
||
| 509 | 3 | $callback = $rule['factory']; |
|
| 510 | 3 | $function = $this->reflectCallback($callback); |
|
| 511 | |||
| 512 | 3 | if ($function->getNumberOfParameters() > 0) { |
|
| 513 | 1 | $callbackArgs = $this->resolveArgs( |
|
| 514 | 1 | $this->makeDefaultArgs($function, (array)$rule['constructorArgs'], $rule), |
|
| 515 | 1 | $args |
|
| 516 | ); |
||
| 517 | |||
| 518 | 1 | $this->instances[$nid] = null; // prevent cyclic dependency from infinite loop. |
|
| 519 | 1 | $this->instances[$nid] = $instance = call_user_func_array($callback, $callbackArgs); |
|
| 520 | } else { |
||
| 521 | 2 | $this->instances[$nid] = $instance = $callback(); |
|
| 522 | } |
||
| 523 | |||
| 524 | // Reflect on the instance so that calls can be made against it. |
||
| 525 | 3 | if (is_object($instance)) { |
|
| 526 | 3 | $class = new \ReflectionClass(get_class($instance)); |
|
| 527 | } |
||
| 528 | } else { |
||
| 529 | 21 | $className = empty($rule['class']) ? $nid : $rule['class']; |
|
| 530 | 21 | if (!class_exists($className)) { |
|
| 531 | 1 | throw new NotFoundException("Class $className does not exist.", 404); |
|
| 532 | } |
||
| 533 | 20 | $class = new \ReflectionClass($className); |
|
| 534 | 20 | $constructor = $class->getConstructor(); |
|
| 535 | |||
| 536 | 20 | if ($constructor && $constructor->getNumberOfParameters() > 0) { |
|
| 537 | // Instantiate the object first so that this instance can be used for cyclic dependencies. |
||
| 538 | 19 | $this->instances[$nid] = $instance = $class->newInstanceWithoutConstructor(); |
|
| 539 | |||
| 540 | 19 | $constructorArgs = $this->resolveArgs( |
|
| 541 | 19 | $this->makeDefaultArgs($constructor, (array)$rule['constructorArgs'], $rule), |
|
| 542 | 19 | $args |
|
| 543 | ); |
||
| 544 | 18 | $constructor->invokeArgs($instance, $constructorArgs); |
|
| 545 | } else { |
||
| 546 | 2 | $this->instances[$nid] = $instance = new $class->name; |
|
| 547 | } |
||
| 548 | } |
||
| 549 | |||
| 550 | // Call subsequent calls on the new object. |
||
| 551 | 22 | if (isset($class) && !empty($rule['calls'])) { |
|
| 552 | 2 | foreach ($rule['calls'] as $call) { |
|
| 553 | 2 | list($methodName, $args) = $call; |
|
| 554 | 2 | $method = $class->getMethod($methodName); |
|
| 555 | |||
| 556 | 2 | $args = $this->resolveArgs( |
|
| 557 | 2 | $this->makeDefaultArgs($method, $args, $rule), |
|
| 558 | 2 | [], |
|
| 559 | 2 | $instance |
|
| 560 | ); |
||
| 561 | |||
| 562 | 2 | $method->invokeArgs($instance, $args); |
|
| 563 | } |
||
| 564 | } |
||
| 565 | |||
| 566 | 22 | return $instance; |
|
| 567 | } |
||
| 568 | |||
| 569 | |||
| 570 | /** |
||
| 571 | * Find the class implemented by an ID. |
||
| 572 | * |
||
| 573 | * This tries to see if a rule exists for a normalized ID and what class it evaluates to. |
||
| 574 | * |
||
| 575 | * @param string $nid The normalized ID to look up. |
||
| 576 | * @return string|null Returns the name of the class associated with the rule or **null** if one could not be found. |
||
| 577 | */ |
||
| 578 | 6 | private function findRuleClass($nid) { |
|
| 589 | |||
| 590 | /** |
||
| 591 | * Make an array of default arguments for a given function. |
||
| 592 | * |
||
| 593 | * @param \ReflectionFunctionAbstract $function The function to make the arguments for. |
||
| 594 | * @param array $ruleArgs An array of default arguments specifically for the function. |
||
| 595 | * @param array $rule The entire rule. |
||
| 596 | * @return array Returns an array in the form `name => defaultValue`. |
||
| 597 | */ |
||
| 598 | 59 | private function makeDefaultArgs(\ReflectionFunctionAbstract $function, array $ruleArgs, array $rule = []) { |
|
| 636 | |||
| 637 | /** |
||
| 638 | * Replace an array of default args with called args. |
||
| 639 | * |
||
| 640 | * @param array $defaultArgs The default arguments from {@link Container::makeDefaultArgs()}. |
||
| 641 | * @param array $args The arguments passed into a creation. |
||
| 642 | * @param mixed $instance An object instance if the arguments are being resolved on an already constructed object. |
||
| 643 | * @return array Returns an array suitable to be applied to a function call. |
||
| 644 | * @throws MissingArgumentException Throws an exception when a required parameter is missing. |
||
| 645 | */ |
||
| 646 | 59 | private function resolveArgs(array $defaultArgs, array $args, $instance = null) { |
|
| 678 | |||
| 679 | /** |
||
| 680 | * Create an instance of a container item. |
||
| 681 | * |
||
| 682 | * This method either creates a new instance or returns an already created shared instance. |
||
| 683 | * |
||
| 684 | * @param string $nid The normalized ID of the container item. |
||
| 685 | * @param array $args Additional arguments to pass to the constructor. |
||
| 686 | * @return object Returns an object instance. |
||
| 687 | */ |
||
| 688 | 66 | private function createInstance($nid, array $args) { |
|
| 701 | |||
| 702 | /** |
||
| 703 | * Call a callback with argument injection. |
||
| 704 | * |
||
| 705 | * @param callable $callback The callback to call. |
||
| 706 | * @param array $args Additional arguments to pass to the callback. |
||
| 707 | * @return mixed Returns the result of the callback. |
||
| 708 | * @throws ContainerException Throws an exception if the callback cannot be understood. |
||
| 709 | */ |
||
| 710 | 4 | public function call(callable $callback, array $args = []) { |
|
| 727 | |||
| 728 | /** |
||
| 729 | * Returns true if the container can return an entry for the given identifier. Returns false otherwise. |
||
| 730 | * |
||
| 731 | * @param string $id Identifier of the entry to look for. |
||
| 732 | * |
||
| 733 | * @return boolean |
||
| 734 | */ |
||
| 735 | 5 | public function has($id) { |
|
| 740 | |||
| 741 | /** |
||
| 742 | * Determines whether a rule has been defined at a given ID. |
||
| 743 | * |
||
| 744 | * @param string $id Identifier of the entry to look for. |
||
| 745 | * @return bool Returns **true** if a rule has been defined or **false** otherwise. |
||
| 746 | */ |
||
| 747 | 4 | public function hasRule($id) { |
|
| 751 | |||
| 752 | /** |
||
| 753 | * Returns true if the container already has an instance for the given identifier. Returns false otherwise. |
||
| 754 | * |
||
| 755 | * @param string $id Identifier of the entry to look for. |
||
| 756 | * |
||
| 757 | * @return bool |
||
| 758 | */ |
||
| 759 | 1 | public function hasInstance($id) { |
|
| 764 | |||
| 765 | /** |
||
| 766 | * Finds an entry of the container by its identifier and returns it. |
||
| 767 | * |
||
| 768 | * @param string $id Identifier of the entry to look for. |
||
| 769 | * |
||
| 770 | * @throws NotFoundException No entry was found for this identifier. |
||
| 771 | * @throws ContainerException Error while retrieving the entry. |
||
| 772 | * |
||
| 773 | * @return mixed Entry. |
||
| 774 | */ |
||
| 775 | 58 | public function get($id) { |
|
| 778 | |||
| 779 | /** |
||
| 780 | * Determine the reflection information for a callback. |
||
| 781 | * |
||
| 782 | * @param callable $callback The callback to reflect. |
||
| 783 | * @return \ReflectionFunctionAbstract Returns the reflection function for the callback. |
||
| 784 | */ |
||
| 785 | 9 | private function reflectCallback(callable $callback) { |
|
| 792 | } |
||
| 793 |
This check looks for
@paramannotations where the type inferred by our type inference engine differs from the declared type.It makes a suggestion as to what type it considers more descriptive.
Most often this is a case of a parameter that can be null in addition to its declared types.