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 a statistic. |
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| 29 | * |
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| 30 | * @param $typeCode code of the category type. |
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| 31 | * @param $categoryCode code of the statistical category. |
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| 32 | * |
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| 33 | * @return Statistic. |
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| 34 | */ |
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| 35 | public function getStatistic($typeCode,$categoryCode) |
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| 46 | |||
| 47 | /** |
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| 48 | * Add a user statistic with no regard to existing Types and Categories. |
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| 49 | * |
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| 50 | * @param string $typeCode code of the category type. |
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| 51 | * @param string $typeDesc description of the category type. |
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| 52 | * @param string $categoryCode code of the statistical category. |
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| 53 | * @param string $categoryDesc description of the statistical category. |
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| 54 | * @param string $note free text description of the statistic. |
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| 55 | * @param string $segment_type (Internal|External) |
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| 56 | * |
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| 57 | * @return Statistic |
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| 58 | */ |
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| 59 | public function addStatisticRaw($typeCode,$typeDesc,$categoryCode,$categoryDesc,$segment_type,$note) |
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| 82 | |||
| 83 | /** |
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| 84 | * Add a user statistic based upon existing Types and Categories. |
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| 85 | * |
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| 86 | * @param string $typeCode code of the category type. |
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| 87 | * @param string $categoryCode code of the statistical category. |
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| 88 | * |
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| 89 | * @return Statistic |
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| 90 | */ |
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| 91 | public function addStatistic($typeCode,$categoryCode,$segmentType,$note) |
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| 122 | |||
| 123 | /** |
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| 124 | * Delete a user statistic. |
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| 125 | * |
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| 126 | * @param string $typeCode code of the category type. |
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| 127 | * @param string $categoryCode code of the statistical category. |
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| 128 | */ |
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| 129 | public function removeStatistic($typeCode,$categoryCode) |
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| 141 | |||
| 142 | /** |
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| 143 | * Update a user statistic. |
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| 144 | * |
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| 145 | */ |
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| 146 | public function updateStatistic($fromTypeCode,$fromCategoryCode,$toTypeCode,$toCategoryCode,$segementType,$note) |
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| 152 | |||
| 153 | /** |
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| 154 | * Get Stats By Type Code. |
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| 155 | * |
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| 156 | * @return Array of Statistics. |
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| 157 | */ |
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| 158 | View Code Duplication | public function getStatsByTypeCode($typeCode) |
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| 169 | |||
| 170 | /** |
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| 171 | * Get Stats by Type Desc. |
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| 172 | * |
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| 173 | * @return Array of statistics. |
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| 174 | */ |
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| 175 | View Code Duplication | public function getStatsByTypeDesc($typeDesc) |
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| 185 | |||
| 186 | /** |
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| 187 | * Get Stats by Category Code. |
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| 188 | * |
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| 189 | * @return Array of Statistics. |
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| 190 | */ |
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| 191 | View Code Duplication | public function getStatsByCategoryCode($categoryCode) |
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| 201 | |||
| 202 | /** |
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| 203 | * Get Stats by Category Desc. |
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| 204 | * |
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| 205 | * @return Array of Statistics. |
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| 206 | */ |
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| 207 | View Code Duplication | public function getStatsByCategoryDesc($categoryDesc) |
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| 217 | |||
| 218 | /** |
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| 219 | * Get Stats by Segment Type. |
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| 220 | * |
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| 221 | * @return Array of Statistics. |
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| 222 | */ |
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| 223 | public function getStatsBySegmentType($segmentType) |
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| 233 | |||
| 234 | /** |
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| 235 | * Search Stats by Note. |
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| 236 | * |
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| 237 | * @return Array of Statistics. |
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| 238 | */ |
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| 239 | public function searchStatsByNote($note) |
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| 249 | |||
| 250 | /** |
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| 251 | * Search Stats by Type Code. |
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| 252 | * |
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| 253 | * @return Array of Statistics. |
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| 254 | */ |
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| 255 | View Code Duplication | public function searchStatsByTypeCode($typeCode) |
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| 265 | |||
| 266 | /** |
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| 267 | * Search Stats by Type Code. |
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| 268 | * |
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| 269 | * @return Array of Statistics. |
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| 270 | */ |
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| 271 | View Code Duplication | public function searchStatsByTypeDesc($typeDesc) |
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| 281 | |||
| 282 | /** |
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| 283 | * Search Stats by Type Code. |
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| 284 | * |
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| 285 | * @return Array of Statistics. |
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| 286 | */ |
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| 287 | View Code Duplication | public function searchStatsByCategoryCode($categoryCode) |
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| 297 | |||
| 298 | /** |
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| 299 | * Search Stats by Type Code. |
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| 300 | * |
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| 301 | * @return Array of Statistics. |
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| 302 | */ |
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| 303 | View Code Duplication | public function searchStatsByCategoryDesc($categoryDesc) |
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| 313 | |||
| 314 | } |
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| 315 |
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.