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 UserStatistics 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 UserStatistics, and based on these observations, apply Extract Interface, too.
| 1 | <?php |
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| 11 | class UserStatistics extends Model |
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| 12 | { |
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| 13 | /** |
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| 14 | * Get the user's statistics. |
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| 15 | * |
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| 16 | * @return Array of Statistics. |
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| 17 | */ |
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| 18 | public function getStatistics() |
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| 26 | |||
| 27 | /** |
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| 28 | * Get the user's statistics. |
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| 29 | * |
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| 30 | * @return array of statistics. |
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| 31 | */ |
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| 32 | public function get() |
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| 40 | |||
| 41 | /** |
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| 42 | * Get a statistic. |
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| 43 | * |
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| 44 | * @param $typeCode code of the category type. |
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| 45 | * @param $categoryCode code of the statistical category. |
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| 46 | * |
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| 47 | * @return Statistic. |
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| 48 | */ |
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| 49 | public function getStatistic($typeCode,$categoryCode) |
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| 60 | |||
| 61 | /** |
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| 62 | * Add a user statistic with no regard to existing Types and Categories. |
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| 63 | * |
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| 64 | * @param string $typeCode code of the category type. |
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| 65 | * @param string $typeDesc description of the category type. |
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| 66 | * @param string $categoryCode code of the statistical category. |
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| 67 | * @param string $categoryDesc description of the statistical category. |
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| 68 | * @param string $note free text description of the statistic. |
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| 69 | * @param string $segment_type (Internal|External) |
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| 70 | * |
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| 71 | * @return Statistic |
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| 72 | */ |
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| 73 | public function addStatisticRaw($typeCode,$typeDesc,$categoryCode,$categoryDesc,$segment_type,$note) |
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| 96 | |||
| 97 | /** |
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| 98 | * Add a user statistic based upon existing Types and Categories. |
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| 99 | * |
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| 100 | * @param string $typeCode code of the category type. |
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| 101 | * @param string $categoryCode code of the statistical category. |
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| 102 | * |
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| 103 | * @return Statistic |
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| 104 | */ |
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| 105 | public function addStatistic($typeCode,$categoryCode,$segmentType,$note) |
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| 138 | |||
| 139 | /** |
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| 140 | * Delete a user statistic. |
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| 141 | * |
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| 142 | * @param string $typeCode code of the category type. |
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| 143 | * @param string $categoryCode code of the statistical category. |
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| 144 | */ |
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| 145 | public function removeStatistic($typeCode,$categoryCode) |
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| 164 | |||
| 165 | /** |
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| 166 | * Update a user statistic. |
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| 167 | * |
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| 168 | */ |
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| 169 | public function updateStatistic($fromTypeCode,$fromCategoryCode,$toTypeCode,$toCategoryCode,$segmentType,$note) |
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| 175 | |||
| 176 | /** |
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| 177 | * Get Stats By Type Code. |
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| 178 | * |
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| 179 | * @return Array of Statistics. |
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| 180 | */ |
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| 181 | View Code Duplication | public function getStatsByTypeCode($typeCode) |
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| 192 | |||
| 193 | /** |
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| 194 | * Get Stats by Type Desc. |
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| 195 | * |
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| 196 | * @return Array of statistics. |
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| 197 | */ |
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| 198 | View Code Duplication | public function getStatsByTypeDesc($typeDesc) |
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| 208 | |||
| 209 | /** |
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| 210 | * Get Stats by Category Code. |
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| 211 | * |
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| 212 | * @return Array of Statistics. |
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| 213 | */ |
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| 214 | View Code Duplication | public function getStatsByCategoryCode($categoryCode) |
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| 224 | |||
| 225 | /** |
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| 226 | * Get Stats by Category Desc. |
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| 227 | * |
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| 228 | * @return Array of Statistics. |
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| 229 | */ |
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| 230 | View Code Duplication | public function getStatsByCategoryDesc($categoryDesc) |
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| 240 | |||
| 241 | /** |
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| 242 | * Get Stats by Segment Type. |
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| 243 | * |
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| 244 | * @return Array of Statistics. |
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| 245 | */ |
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| 246 | public function getStatsBySegmentType($segmentType) |
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| 256 | |||
| 257 | /** |
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| 258 | * Search Stats by Note. |
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| 259 | * |
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| 260 | * @return Array of Statistics. |
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| 261 | */ |
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| 262 | public function searchStatsByNote($note) |
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| 272 | |||
| 273 | /** |
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| 274 | * Search Stats by Type Code. |
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| 275 | * |
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| 276 | * @return Array of Statistics. |
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| 277 | */ |
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| 278 | View Code Duplication | public function searchStatsByTypeCode($typeCode) |
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| 288 | |||
| 289 | /** |
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| 290 | * Search Stats by Type Code. |
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| 291 | * |
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| 292 | * @return Array of Statistics. |
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| 293 | */ |
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| 294 | View Code Duplication | public function searchStatsByTypeDesc($typeDesc) |
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| 304 | |||
| 305 | /** |
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| 306 | * Search Stats by Type Code. |
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| 307 | * |
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| 308 | * @return Array of Statistics. |
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| 309 | */ |
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| 310 | View Code Duplication | public function searchStatsByCategoryCode($categoryCode) |
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| 320 | |||
| 321 | /** |
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| 322 | * Search Stats by Type Code. |
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| 323 | * |
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| 324 | * @return Array of Statistics. |
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| 325 | */ |
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| 326 | View Code Duplication | public function searchStatsByCategoryDesc($categoryDesc) |
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| 336 | |||
| 337 | } |
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| 338 |
There are different options of fixing this problem.
If you want to be on the safe side, you can add an additional type-check:
If you are sure that the expression is traversable, you might want to add a doc comment cast to improve IDE auto-completion and static analysis:
Mark the issue as a false-positive: Just hover the remove button, in the top-right corner of this issue for more options.