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 DoctrineExtension 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 DoctrineExtension, and based on these observations, apply Extract Interface, too.
1 | <?php |
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23 | class DoctrineExtension extends \Twig_Extension |
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24 | { |
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25 | /** |
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26 | * Number of maximum characters that one single line can hold in the interface |
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27 | * |
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28 | * @var int |
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29 | */ |
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30 | private $maxCharWidth = 100; |
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31 | |||
32 | /** |
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33 | * Define our functions |
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34 | * |
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35 | * @return \Twig_SimpleFilter[] |
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36 | */ |
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37 | public function getFilters() |
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38 | { |
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39 | return array( |
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40 | new \Twig_SimpleFilter('doctrine_minify_query', array($this, 'minifyQuery'), array('deprecated' => true)), |
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41 | new \Twig_SimpleFilter('doctrine_pretty_query', array($this, 'formatQuery'), array('is_safe' => array('html'))), |
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42 | new \Twig_SimpleFilter('doctrine_replace_query_parameters', array($this, 'replaceQueryParameters')), |
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43 | ); |
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44 | } |
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45 | |||
46 | /** |
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47 | * Get the possible combinations of elements from the given array |
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48 | * |
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49 | * @param array $elements |
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50 | * @param integer $combinationsLevel |
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51 | * |
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52 | * @return array |
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53 | */ |
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54 | private function getPossibleCombinations(array $elements, $combinationsLevel) |
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55 | { |
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56 | $baseCount = count($elements); |
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57 | $result = array(); |
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58 | |||
59 | if (1 === $combinationsLevel) { |
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60 | foreach ($elements as $element) { |
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61 | $result[] = array($element); |
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62 | } |
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63 | |||
64 | return $result; |
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65 | } |
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66 | |||
67 | $nextLevelElements = $this->getPossibleCombinations($elements, $combinationsLevel - 1); |
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68 | |||
69 | foreach ($nextLevelElements as $nextLevelElement) { |
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70 | $lastElement = $nextLevelElement[$combinationsLevel - 2]; |
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71 | $found = false; |
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72 | |||
73 | foreach ($elements as $key => $element) { |
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74 | if ($element == $lastElement) { |
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75 | $found = true; |
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76 | continue; |
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77 | } |
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78 | |||
79 | if ($found == true && $key < $baseCount) { |
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80 | $tmp = $nextLevelElement; |
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81 | $newCombination = array_slice($tmp, 0); |
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82 | $newCombination[] = $element; |
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83 | $result[] = array_slice($newCombination, 0); |
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84 | } |
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85 | } |
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86 | } |
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87 | |||
88 | return $result; |
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89 | } |
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90 | |||
91 | /** |
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92 | * Shrink the values of parameters from a combination |
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93 | * |
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94 | * @param array $parameters |
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95 | * @param array $combination |
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96 | * |
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97 | * @return string |
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98 | */ |
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99 | private function shrinkParameters(array $parameters, array $combination) |
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133 | |||
134 | /** |
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135 | * Attempt to compose the best scenario minified query so that a user could find it without expanding it |
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136 | * |
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137 | * @param string $query |
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138 | * @param array $keywords |
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139 | * @param integer $required |
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140 | * |
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141 | * @return string |
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142 | */ |
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143 | private function composeMiniQuery($query, array $keywords, $required) |
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186 | |||
187 | /** |
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188 | * Minify the query |
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189 | * |
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190 | * @param string $query |
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191 | * |
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192 | * @return string |
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193 | */ |
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194 | public function minifyQuery($query) |
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234 | |||
235 | /** |
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236 | * Escape parameters of a SQL query |
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237 | * DON'T USE THIS FUNCTION OUTSIDE ITS INTENDED SCOPE |
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238 | * |
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239 | * @internal |
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240 | * |
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241 | * @param mixed $parameter |
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242 | * |
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243 | * @return string |
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244 | */ |
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245 | public static function escapeFunction($parameter) |
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246 | { |
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247 | $result = $parameter; |
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248 | |||
249 | switch (true) { |
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250 | // Check if result is non-unicode string using PCRE_UTF8 modifier |
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251 | case is_string($result) && !preg_match('//u', $result): |
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252 | $result = '0x'. strtoupper(bin2hex($result)); |
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253 | break; |
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254 | |||
255 | case is_string($result): |
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256 | $result = "'".addslashes($result)."'"; |
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257 | break; |
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258 | |||
259 | case is_array($result): |
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260 | foreach ($result as &$value) { |
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261 | $value = static::escapeFunction($value); |
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262 | } |
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263 | |||
264 | $result = implode(', ', $result); |
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265 | break; |
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266 | |||
267 | case is_object($result): |
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268 | $result = addslashes((string) $result); |
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269 | break; |
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270 | |||
271 | case null === $result: |
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272 | $result = 'NULL'; |
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273 | break; |
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274 | |||
275 | case is_bool($result): |
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276 | $result = $result ? '1' : '0'; |
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277 | break; |
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278 | } |
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279 | |||
280 | return $result; |
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281 | } |
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282 | |||
283 | /** |
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284 | * Return a query with the parameters replaced |
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285 | * |
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286 | * @param string $query |
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287 | * @param array $parameters |
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288 | * |
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289 | * @return string |
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290 | */ |
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291 | public function replaceQueryParameters($query, array $parameters) |
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318 | |||
319 | /** |
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320 | * Formats and/or highlights the given SQL statement. |
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321 | * |
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322 | * @param string $sql |
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323 | * @param bool $highlightOnly If true the query is not formatted, just highlighted |
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324 | * |
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325 | * @return string |
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326 | */ |
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327 | public function formatQuery($sql, $highlightOnly = false) |
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350 | |||
351 | /** |
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352 | * Get the name of the extension |
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353 | * |
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354 | * @return string |
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355 | */ |
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356 | public function getName() |
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360 | } |
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361 |
When comparing two booleans, it is generally considered safer to use the strict comparison operator.