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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136 | |||
137 | /** |
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138 | * {@inheritdoc} |
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139 | */ |
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140 | public function resolveArguments(ContextFunction $reflection, array $parameters = []) |
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202 | |||
203 | /** |
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204 | * {@inheritdoc} |
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205 | * |
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206 | * @return $this |
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207 | */ |
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208 | View Code Duplication | public function bind($alias, $resolver) |
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220 | |||
221 | /** |
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222 | * {@inheritdoc} |
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223 | * |
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224 | * @return $this |
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225 | */ |
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226 | View Code Duplication | public function bindSingleton($alias, $resolver) |
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238 | |||
239 | /** |
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240 | * {@inheritdoc} |
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241 | * |
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242 | * @return $this |
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243 | */ |
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244 | public function bindInjector($class, $injector) |
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250 | |||
251 | /** |
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252 | * {@inheritdoc} |
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253 | */ |
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254 | public function replace($alias, $resolver) |
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265 | |||
266 | /** |
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267 | * {@inheritdoc} |
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268 | */ |
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269 | public function restore($replacePayload) |
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280 | |||
281 | /** |
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282 | * {@inheritdoc} |
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283 | */ |
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284 | public function hasInstance($alias) |
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297 | |||
298 | /** |
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299 | * {@inheritdoc} |
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300 | */ |
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301 | public function removeBinding($alias) |
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305 | |||
306 | /** |
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307 | * Every declared Container binding. Must not be used in production code due container format is |
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308 | * vary. |
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309 | * |
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310 | * @return array |
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311 | */ |
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312 | public function getBindings() |
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316 | |||
317 | /** |
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318 | * Every binded injector. |
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319 | * |
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320 | * @return array |
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321 | */ |
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322 | public function getInjectors() |
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326 | |||
327 | /** |
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328 | * Automatically create class. |
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329 | * |
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330 | * @param string $class |
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331 | * @param array $parameters |
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332 | * @param string $context |
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333 | * @return object |
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334 | * @throws AutowireException |
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335 | */ |
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336 | protected function autowire($class, array $parameters, $context) |
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347 | |||
348 | /** |
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349 | * Check if given class has associated injector. |
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350 | * |
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351 | * @todo replace with Context on demand |
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352 | * @param \ReflectionClass $reflection |
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353 | * @return bool |
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354 | */ |
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355 | protected function hasInjector(\ReflectionClass $reflection) |
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363 | |||
364 | /** |
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365 | * Get injector associated with given class. |
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366 | * |
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367 | * @todo replace with Context on demand |
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368 | * @param \ReflectionClass $reflection |
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369 | * @return InjectorInterface |
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370 | */ |
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371 | protected function getInjector(\ReflectionClass $reflection) |
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379 | |||
380 | /** |
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381 | * Create instance of desired class. |
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382 | * |
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383 | * @param string $class |
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384 | * @param array $parameters Constructor parameters. |
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385 | * @param string|null $context |
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386 | * @param \ReflectionClass $reflection Instance of reflection associated with class, |
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387 | * reference. |
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388 | * @return object |
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389 | * @throws ContainerException |
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390 | */ |
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391 | private function createInstance( |
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438 | |||
439 | |||
440 | /** |
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441 | * Make sure instance conditions are met |
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442 | * |
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443 | * @param object $instance |
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444 | * @param \ReflectionClass $reflector |
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445 | * @param array $parameters |
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446 | * @return object |
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447 | */ |
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448 | private function registerInstance($instance, \ReflectionClass $reflector, array $parameters) |
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464 | } |
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: