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 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 |
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31 | class Container extends Component implements ContainerInterface, FactoryInterface, ResolverInterface |
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32 | { |
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33 | /** |
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34 | * IoC bindings. |
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35 | * |
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36 | * @invisible |
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37 | * @var array |
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38 | */ |
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39 | protected $bindings = []; |
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40 | |||
41 | /** |
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42 | * Registered injectors. |
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43 | * |
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44 | * @invisible |
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45 | * @var array |
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46 | */ |
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47 | protected $injectors = []; |
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48 | |||
49 | /** |
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50 | * {@inheritdoc} |
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51 | */ |
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52 | public function has($alias) |
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56 | |||
57 | /** |
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58 | * {@inheritdoc} |
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59 | * |
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60 | * Context parameter will be passed to class injectors, which makes possible to use this method |
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61 | * as: |
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62 | * $this->container->get(DatabaseInterface::class, 'default'); |
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63 | * |
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64 | * @param string|null $context Call context. |
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65 | */ |
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66 | public function get($alias, $context = null) |
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71 | |||
72 | /** |
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73 | * {@inheritdoc} |
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74 | * |
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75 | * @param string|null $context Related to parameter caused injection if any. |
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76 | */ |
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77 | public function make($class, $parameters = [], $context = null) |
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144 | |||
145 | /** |
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146 | * {@inheritdoc} |
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147 | */ |
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148 | public function resolveArguments(ContextFunction $reflection, array $parameters = []) |
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210 | |||
211 | /** |
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212 | * {@inheritdoc} |
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213 | * |
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214 | * @return $this |
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215 | */ |
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216 | View Code Duplication | public function bind($alias, $resolver) |
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228 | |||
229 | /** |
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230 | * {@inheritdoc} |
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231 | * |
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232 | * @return $this |
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233 | */ |
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234 | View Code Duplication | public function bindSingleton($alias, $resolver) |
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246 | |||
247 | /** |
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248 | * {@inheritdoc} |
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249 | * |
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250 | * @return $this |
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251 | */ |
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252 | public function bindInjector($class, $injector) |
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258 | |||
259 | /** |
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260 | * {@inheritdoc} |
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261 | */ |
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262 | public function replace($alias, $resolver) |
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273 | |||
274 | /** |
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275 | * {@inheritdoc} |
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276 | */ |
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277 | public function restore($replacePayload) |
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288 | |||
289 | /** |
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290 | * {@inheritdoc} |
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291 | */ |
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292 | public function hasInstance($alias) |
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305 | |||
306 | /** |
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307 | * {@inheritdoc} |
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308 | */ |
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309 | public function removeBinding($alias) |
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313 | |||
314 | /** |
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315 | * Every declared Container binding. Must not be used in production code due container format is |
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316 | * vary. |
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317 | * |
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318 | * @return array |
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319 | */ |
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320 | public function getBindings() |
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324 | |||
325 | /** |
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326 | * Every binded injector. |
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327 | * |
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328 | * @return array |
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329 | */ |
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330 | public function getInjectors() |
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334 | |||
335 | /** |
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336 | * Automatically create class. |
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337 | * |
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338 | * @param string $class |
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339 | * @param array $parameters |
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340 | * @param string $context |
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341 | * @return object |
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342 | * @throws AutowireException |
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343 | */ |
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344 | protected function autowire($class, array $parameters, $context) |
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355 | |||
356 | /** |
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357 | * Check if given class has associated injector. |
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358 | * |
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359 | * @todo replace with Context on demand |
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360 | * @param \ReflectionClass $reflection |
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361 | * @return bool |
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362 | */ |
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363 | protected function hasInjector(\ReflectionClass $reflection) |
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371 | |||
372 | /** |
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373 | * Get injector associated with given class. |
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374 | * |
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375 | * @todo replace with Context on demand |
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376 | * @param \ReflectionClass $reflection |
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377 | * @return InjectorInterface |
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378 | */ |
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379 | protected function getInjector(\ReflectionClass $reflection) |
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387 | |||
388 | /** |
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389 | * Create instance of desired class. |
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390 | * |
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391 | * @param string $class |
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392 | * @param array $parameters Constructor parameters. |
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393 | * @param string|null $context |
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394 | * @param \ReflectionClass $reflection Instance of reflection associated with class, |
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395 | * reference. |
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396 | * @return object |
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397 | * @throws ContainerException |
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398 | */ |
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399 | private function createInstance( |
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446 | |||
447 | |||
448 | /** |
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449 | * Make sure instance conditions are met |
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450 | * |
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451 | * @param object $instance |
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452 | * @param \ReflectionClass $reflector |
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453 | * @param array $parameters |
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454 | * @return object |
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455 | */ |
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456 | private function registerInstance($instance, \ReflectionClass $reflector, array $parameters) |
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472 | } |
Unless you are absolutely sure that the expression can never be null because of other conditions, we strongly recommend to add an additional type check to your code: