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 PHPCompatibility_Sniff 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 PHPCompatibility_Sniff, and based on these observations, apply Extract Interface, too.
1 | <?php |
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22 | abstract class PHPCompatibility_Sniff implements PHP_CodeSniffer_Sniff |
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23 | { |
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24 | |||
25 | /* The testVersion configuration variable may be in any of the following formats: |
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26 | * 1) Omitted/empty, in which case no version is specified. This effectively |
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27 | * disables all the checks provided by this standard. |
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28 | * 2) A single PHP version number, e.g. "5.4" in which case the standard checks that |
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29 | * the code will run on that version of PHP (no deprecated features or newer |
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30 | * features being used). |
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31 | * 3) A range, e.g. "5.0-5.5", in which case the standard checks the code will run |
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32 | * on all PHP versions in that range, and that it doesn't use any features that |
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33 | * were deprecated by the final version in the list, or which were not available |
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34 | * for the first version in the list. |
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35 | * PHP version numbers should always be in Major.Minor format. Both "5", "5.3.2" |
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36 | * would be treated as invalid, and ignored. |
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37 | * This standard doesn't support checking against PHP4, so the minimum version that |
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38 | * is recognised is "5.0". |
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39 | */ |
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40 | |||
41 | private function getTestVersion() |
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82 | |||
83 | View Code Duplication | public function supportsAbove($phpVersion) |
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96 | |||
97 | View Code Duplication | public function supportsBelow($phpVersion) |
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110 | |||
111 | /** |
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112 | * Returns the name(s) of the interface(s) that the specified class implements. |
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113 | * |
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114 | * Returns FALSE on error or if there are no implemented interface names. |
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115 | * |
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116 | * {@internal Duplicate of same method as introduced in PHPCS 2.7. |
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117 | * Once the minimum supported PHPCS version for this sniff library goes beyond |
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118 | * that, this method can be removed and call to it replaced with |
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119 | * `$phpcsFile->findImplementedInterfaceNames($stackPtr)` calls.}} |
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120 | * |
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121 | * @param PHP_CodeSniffer_File $phpcsFile The file being scanned. |
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122 | * @param int $stackPtr The position of the class token. |
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123 | * |
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124 | * @return array|false |
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125 | */ |
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126 | public function findImplementedInterfaceNames($phpcsFile, $stackPtr) |
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169 | |||
170 | |||
171 | /** |
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172 | * Checks if a function call has parameters. |
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173 | * |
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174 | * Expects to be passed the T_STRING stack pointer for the function call. |
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175 | * If passed a T_STRING which is *not* a function call, the behaviour is unreliable. |
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176 | * |
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177 | * @link https://github.com/wimg/PHPCompatibility/issues/120 |
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178 | * @link https://github.com/wimg/PHPCompatibility/issues/152 |
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179 | * |
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180 | * @param PHP_CodeSniffer_File $phpcsFile The file being scanned. |
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181 | * @param int $stackPtr The position of the function call token. |
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182 | * |
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183 | * @return bool |
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184 | */ |
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185 | public function doesFunctionCallHaveParameters(PHP_CodeSniffer_File $phpcsFile, $stackPtr) |
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218 | |||
219 | |||
220 | /** |
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221 | * Count the number of parameters a function call has been passed. |
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222 | * |
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223 | * Expects to be passed the T_STRING stack pointer for the function call. |
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224 | * If passed a T_STRING which is *not* a function call, the behaviour is unreliable. |
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225 | * |
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226 | * @link https://github.com/wimg/PHPCompatibility/issues/111 |
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227 | * @link https://github.com/wimg/PHPCompatibility/issues/114 |
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228 | * @link https://github.com/wimg/PHPCompatibility/issues/151 |
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229 | * |
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230 | * @param PHP_CodeSniffer_File $phpcsFile The file being scanned. |
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231 | * @param int $stackPtr The position of the function call token. |
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232 | * |
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233 | * @return int |
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234 | */ |
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235 | public function getFunctionCallParameterCount(PHP_CodeSniffer_File $phpcsFile, $stackPtr) |
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243 | |||
244 | |||
245 | /** |
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246 | * Get information on all parameters passed to a function call. |
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247 | * |
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248 | * Expects to be passed the T_STRING stack pointer for the function call. |
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249 | * If passed a T_STRING which is *not* a function call, the behaviour is unreliable. |
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250 | * |
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251 | * Will return an multi-dimentional array with the start token pointer, end token |
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252 | * pointer and raw parameter value for all parameters. Index will be 1-based. |
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253 | * If no parameters are found, will return an empty array. |
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254 | * |
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255 | * @param PHP_CodeSniffer_File $phpcsFile The file being scanned. |
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256 | * @param int $stackPtr The position of the function call token. |
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257 | * |
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258 | * @return array |
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259 | */ |
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260 | public function getFunctionCallParameters(PHP_CodeSniffer_File $phpcsFile, $stackPtr) |
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332 | |||
333 | |||
334 | /** |
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335 | * Get information on a specific parameter passed to a function call. |
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336 | * |
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337 | * Expects to be passed the T_STRING stack pointer for the function call. |
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338 | * If passed a T_STRING which is *not* a function call, the behaviour is unreliable. |
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339 | * |
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340 | * Will return a array with the start token pointer, end token pointer and the raw value |
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341 | * of the parameter at a specific offset. |
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342 | * If the specified parameter is not found, will return false. |
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343 | * |
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344 | * @param PHP_CodeSniffer_File $phpcsFile The file being scanned. |
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345 | * @param int $stackPtr The position of the function call token. |
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346 | * @param int $paramOffset The 1-based index position of the parameter to retrieve. |
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347 | * |
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348 | * @return array|false |
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349 | */ |
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350 | public function getFunctionCallParameter(PHP_CodeSniffer_File $phpcsFile, $stackPtr, $paramOffset) |
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361 | |||
362 | |||
363 | /** |
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364 | * Verify whether a token is within a class scope. |
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365 | * |
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366 | * @param PHP_CodeSniffer_File $phpcsFile The file being scanned. |
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367 | * @param int $stackPtr The position of the token. |
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368 | * @param bool $strict Whether to strictly check for the T_CLASS |
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369 | * scope or also accept interfaces and traits |
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370 | * as scope. |
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371 | * |
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372 | * @return bool True if within class scope, false otherwise. |
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373 | */ |
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374 | public function inClassScope(PHP_CodeSniffer_File $phpcsFile, $stackPtr, $strict = true) |
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403 | |||
404 | |||
405 | /** |
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406 | * Returns the fully qualified class name for a new class instantiation. |
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407 | * |
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408 | * Returns an empty string if the class name could not be reliably inferred. |
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409 | * |
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410 | * @param PHP_CodeSniffer_File $phpcsFile The file being scanned. |
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411 | * @param int $stackPtr The position of a T_NEW token. |
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412 | * |
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413 | * @return string |
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414 | */ |
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415 | public function getFQClassNameFromNewToken(PHP_CodeSniffer_File $phpcsFile, $stackPtr) |
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447 | |||
448 | |||
449 | /** |
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450 | * Returns the fully qualified name of the class that the specified class extends. |
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451 | * |
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452 | * Returns an empty string if the class does not extend another class or if |
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453 | * the class name could not be reliably inferred. |
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454 | * |
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455 | * @param PHP_CodeSniffer_File $phpcsFile The file being scanned. |
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456 | * @param int $stackPtr The position of a T_CLASS token. |
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457 | * |
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458 | * @return string |
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459 | */ |
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460 | public function getFQExtendedClassName(PHP_CodeSniffer_File $phpcsFile, $stackPtr) |
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480 | |||
481 | |||
482 | /** |
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483 | * Returns the class name for the static usage of a class. |
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484 | * This can be a call to a method, the use of a property or constant. |
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485 | * |
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486 | * Returns an empty string if the class name could not be reliably inferred. |
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487 | * |
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488 | * @param PHP_CodeSniffer_File $phpcsFile The file being scanned. |
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489 | * @param int $stackPtr The position of a T_NEW token. |
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490 | * |
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491 | * @return string |
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492 | */ |
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493 | public function getFQClassNameFromDoubleColonToken(PHP_CodeSniffer_File $phpcsFile, $stackPtr) |
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539 | |||
540 | |||
541 | /** |
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542 | * Get the Fully Qualified name for a class/function/constant etc. |
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543 | * |
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544 | * Checks if a class/function/constant name is already fully qualified and |
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545 | * if not, enrich it with the relevant namespace information. |
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546 | * |
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547 | * @param PHP_CodeSniffer_File $phpcsFile The file being scanned. |
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548 | * @param int $stackPtr The position of the token. |
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549 | * @param string $name The class / function / constant name. |
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550 | * |
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551 | * @return string |
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552 | */ |
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553 | public function getFQName(PHP_CodeSniffer_File $phpcsFile, $stackPtr, $name) |
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574 | |||
575 | |||
576 | /** |
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577 | * Is the class/function/constant name namespaced or global ? |
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578 | * |
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579 | * @param string $FQName Fully Qualified name of a class, function etc. |
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580 | * I.e. should always start with a `\` ! |
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581 | * |
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582 | * @return bool True if namespaced, false if global. |
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583 | */ |
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584 | public function isNamespaced($FQName) { |
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591 | |||
592 | |||
593 | /** |
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594 | * Determine the namespace name an arbitrary token lives in. |
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595 | * |
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596 | * @param PHP_CodeSniffer_File $phpcsFile Instance of phpcsFile. |
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597 | * @param int $stackPtr The token position for which to determine the namespace. |
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598 | * |
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599 | * @return string Namespace name or empty string if it couldn't be determined or no namespace applies. |
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600 | */ |
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601 | public function determineNamespace(PHP_CodeSniffer_File $phpcsFile, $stackPtr) |
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651 | |||
652 | /** |
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653 | * Get the complete namespace name for a namespace declaration. |
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654 | * |
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655 | * For hierarchical namespaces, the name will be composed of several tokens, |
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656 | * i.e. MyProject\Sub\Level which will be returned together as one string. |
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657 | * |
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658 | * @param PHP_CodeSniffer_File $phpcsFile Instance of phpcsFile. |
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659 | * @param int|bool $stackPtr The position of a T_NAMESPACE token. |
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660 | * |
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661 | * @return string|false Namespace name or false if not a namespace declaration. |
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662 | * Namespace name can be an empty string for global namespace declaration. |
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663 | */ |
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664 | public function getDeclaredNamespaceName(PHP_CodeSniffer_File $phpcsFile, $stackPtr ) |
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704 | |||
705 | |||
706 | /** |
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707 | * Returns the method parameters for the specified T_FUNCTION token. |
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708 | * |
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709 | * Each parameter is in the following format: |
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710 | * |
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711 | * <code> |
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712 | * 0 => array( |
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713 | * 'name' => '$var', // The variable name. |
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714 | * 'pass_by_reference' => false, // Passed by reference. |
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715 | * 'type_hint' => string, // Type hint for array or custom type |
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716 | * ) |
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717 | * </code> |
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718 | * |
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719 | * Parameters with default values have an additional array index of |
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720 | * 'default' with the value of the default as a string. |
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721 | * |
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722 | * {@internal Duplicate of same method as contained in the `PHP_CodeSniffer_File` |
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723 | * class, but with some improvements which were only introduced in PHPCS 2.7. |
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724 | * Once the minimum supported PHPCS version for this sniff library goes beyond |
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725 | * that, this method can be removed and calls to it replaced with |
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726 | * `$phpcsFile->getMethodParameters($stackPtr)` calls.}} |
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727 | * |
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728 | * @param PHP_CodeSniffer_File $phpcsFile Instance of phpcsFile. |
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729 | * @param int $stackPtr The position in the stack of the T_FUNCTION token |
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730 | * to acquire the parameters for. |
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731 | * |
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732 | * @return array |
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733 | * @throws PHP_CodeSniffer_Exception If the specified $stackPtr is not of |
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734 | * type T_FUNCTION. |
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735 | */ |
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736 | public function getMethodParameters(PHP_CodeSniffer_File $phpcsFile, $stackPtr) |
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881 | |||
882 | }//end class |
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883 |
Duplicated code is one of the most pungent code smells. If you need to duplicate the same code in three or more different places, we strongly encourage you to look into extracting the code into a single class or operation.
You can also find more detailed suggestions in the “Code” section of your repository.