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 ClassLoader 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 ClassLoader, and based on these observations, apply Extract Interface, too.
1 | <?php |
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43 | class ClassLoader |
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44 | { |
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45 | // PSR-4 |
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46 | private $prefixLengthsPsr4 = array(); |
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47 | private $prefixDirsPsr4 = array(); |
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48 | private $fallbackDirsPsr4 = array(); |
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49 | |||
50 | // PSR-0 |
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51 | private $prefixesPsr0 = array(); |
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52 | private $fallbackDirsPsr0 = array(); |
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53 | |||
54 | private $useIncludePath = false; |
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55 | private $classMap = array(); |
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56 | private $classMapAuthoritative = false; |
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57 | private $missingClasses = array(); |
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58 | private $apcuPrefix; |
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59 | |||
60 | public function getPrefixes() |
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68 | |||
69 | public function getPrefixesPsr4() |
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73 | |||
74 | public function getFallbackDirs() |
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78 | |||
79 | public function getFallbackDirsPsr4() |
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83 | |||
84 | public function getClassMap() |
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88 | |||
89 | /** |
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90 | * @param array $classMap Class to filename map |
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91 | */ |
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92 | public function addClassMap(array $classMap) |
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100 | |||
101 | /** |
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102 | * Registers a set of PSR-0 directories for a given prefix, either |
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103 | * appending or prepending to the ones previously set for this prefix. |
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104 | * |
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105 | * @param string $prefix The prefix |
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106 | * @param array|string $paths The PSR-0 root directories |
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107 | * @param bool $prepend Whether to prepend the directories |
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108 | */ |
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109 | public function add($prefix, $paths, $prepend = false) |
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145 | |||
146 | /** |
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147 | * Registers a set of PSR-4 directories for a given namespace, either |
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148 | * appending or prepending to the ones previously set for this namespace. |
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149 | * |
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150 | * @param string $prefix The prefix/namespace, with trailing '\\' |
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151 | * @param array|string $paths The PSR-4 base directories |
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152 | * @param bool $prepend Whether to prepend the directories |
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153 | * |
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154 | * @throws \InvalidArgumentException |
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155 | */ |
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156 | public function addPsr4($prefix, $paths, $prepend = false) |
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193 | |||
194 | /** |
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195 | * Registers a set of PSR-0 directories for a given prefix, |
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196 | * replacing any others previously set for this prefix. |
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197 | * |
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198 | * @param string $prefix The prefix |
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199 | * @param array|string $paths The PSR-0 base directories |
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200 | */ |
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201 | public function set($prefix, $paths) |
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209 | |||
210 | /** |
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211 | * Registers a set of PSR-4 directories for a given namespace, |
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212 | * replacing any others previously set for this namespace. |
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213 | * |
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214 | * @param string $prefix The prefix/namespace, with trailing '\\' |
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215 | * @param array|string $paths The PSR-4 base directories |
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216 | * |
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217 | * @throws \InvalidArgumentException |
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218 | */ |
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219 | public function setPsr4($prefix, $paths) |
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232 | |||
233 | /** |
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234 | * Turns on searching the include path for class files. |
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235 | * |
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236 | * @param bool $useIncludePath |
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237 | */ |
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238 | public function setUseIncludePath($useIncludePath) |
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242 | |||
243 | /** |
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244 | * Can be used to check if the autoloader uses the include path to check |
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245 | * for classes. |
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246 | * |
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247 | * @return bool |
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248 | */ |
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249 | public function getUseIncludePath() |
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253 | |||
254 | /** |
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255 | * Turns off searching the prefix and fallback directories for classes |
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256 | * that have not been registered with the class map. |
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257 | * |
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258 | * @param bool $classMapAuthoritative |
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259 | */ |
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260 | public function setClassMapAuthoritative($classMapAuthoritative) |
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264 | |||
265 | /** |
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266 | * Should class lookup fail if not found in the current class map? |
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267 | * |
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268 | * @return bool |
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269 | */ |
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270 | public function isClassMapAuthoritative() |
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274 | |||
275 | /** |
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276 | * APCu prefix to use to cache found/not-found classes, if the extension is enabled. |
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277 | * |
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278 | * @param string|null $apcuPrefix |
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279 | */ |
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280 | public function setApcuPrefix($apcuPrefix) |
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284 | |||
285 | /** |
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286 | * The APCu prefix in use, or null if APCu caching is not enabled. |
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287 | * |
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288 | * @return string|null |
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289 | */ |
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290 | public function getApcuPrefix() |
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294 | |||
295 | /** |
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296 | * Registers this instance as an autoloader. |
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297 | * |
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298 | * @param bool $prepend Whether to prepend the autoloader or not |
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299 | */ |
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300 | public function register($prepend = false) |
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304 | |||
305 | /** |
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306 | * Unregisters this instance as an autoloader. |
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307 | */ |
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308 | public function unregister() |
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312 | |||
313 | /** |
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314 | * Loads the given class or interface. |
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315 | * |
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316 | * @param string $class The name of the class |
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317 | * @return bool|null True if loaded, null otherwise |
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318 | */ |
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319 | public function loadClass($class) |
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327 | |||
328 | /** |
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329 | * Finds the path to the file where the class is defined. |
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330 | * |
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331 | * @param string $class The name of the class |
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332 | * |
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333 | * @return string|false The path if found, false otherwise |
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334 | */ |
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335 | public function findFile($class) |
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369 | |||
370 | private function findFileWithExtension($class, $ext) |
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435 | } |
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436 | |||
446 |
This check marks implicit conversions of arrays to boolean values in a comparison. While in PHP an empty array is considered to be equal (but not identical) to false, this is not always apparent.
Consider making the comparison explicit by using
empty(..)
or! empty(...)
instead.