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 | ||
| 11 | class UserStatistics extends Model | ||
| 12 | { | ||
| 13 | /** | ||
| 14 | * Get the user's statistics. | ||
| 15 | * | ||
| 16 | * @return Array of Statistics. | ||
| 17 | */ | ||
| 18 | public function getStatistics() | ||
| 26 | |||
| 27 | /** | ||
| 28 | * Get the user's statistics. | ||
| 29 | * | ||
| 30 | * @return array of statistics. | ||
| 31 | */ | ||
| 32 | public function get() | ||
| 40 | |||
| 41 | /** | ||
| 42 | * Get a statistic. | ||
| 43 | * | ||
| 44 | * @param $typeCode code of the category type. | ||
| 45 | * @param $categoryCode code of the statistical category. | ||
| 46 | * | ||
| 47 | * @return Statistic. | ||
| 48 | */ | ||
| 49 | public function getStatistic($typeCode,$categoryCode) | ||
| 60 | |||
| 61 | /** | ||
| 62 | * Add a user statistic with no regard to existing Types and Categories. | ||
| 63 | * | ||
| 64 | * @param string $typeCode code of the category type. | ||
| 65 | * @param string $typeDesc description of the category type. | ||
| 66 | * @param string $categoryCode code of the statistical category. | ||
| 67 | * @param string $categoryDesc description of the statistical category. | ||
| 68 | * @param string $note free text description of the statistic. | ||
| 69 | * @param string $segment_type (Internal|External) | ||
| 70 | * | ||
| 71 | * @return Statistic | ||
| 72 | */ | ||
| 73 | public function addStatisticRaw($typeCode,$typeDesc,$categoryCode,$categoryDesc,$segment_type,$note) | ||
| 96 | |||
| 97 | /** | ||
| 98 | * Add a user statistic based upon existing Types and Categories. | ||
| 99 | * | ||
| 100 | * @param string $typeCode code of the category type. | ||
| 101 | * @param string $categoryCode code of the statistical category. | ||
| 102 | * | ||
| 103 | * @return Statistic | ||
| 104 | */ | ||
| 105 | public function addStatistic($typeCode,$categoryCode,$segmentType,$note) | ||
| 138 | |||
| 139 | /** | ||
| 140 | * Delete a user statistic. | ||
| 141 | * | ||
| 142 | * @param string $typeCode code of the category type. | ||
| 143 | * @param string $categoryCode code of the statistical category. | ||
| 144 | */ | ||
| 145 | public function removeStatistic($typeCode,$categoryCode) | ||
| 164 | |||
| 165 | /** | ||
| 166 | * Update a user statistic. | ||
| 167 | * | ||
| 168 | */ | ||
| 169 | public function updateStatistic($fromTypeCode,$fromCategoryCode,$toTypeCode,$toCategoryCode,$segmentType,$note) | ||
| 175 | |||
| 176 | /** | ||
| 177 | * Get Stats By Type Code. | ||
| 178 | * | ||
| 179 | * @return Array of Statistics. | ||
| 180 | */ | ||
| 181 | View Code Duplication | public function getStatsByTypeCode($typeCode) | |
| 192 | |||
| 193 | /** | ||
| 194 | * Get Stats by Type Desc. | ||
| 195 | * | ||
| 196 | * @return Array of statistics. | ||
| 197 | */ | ||
| 198 | View Code Duplication | public function getStatsByTypeDesc($typeDesc) | |
| 208 | |||
| 209 | /** | ||
| 210 | * Get Stats by Category Code. | ||
| 211 | * | ||
| 212 | * @return Array of Statistics. | ||
| 213 | */ | ||
| 214 | View Code Duplication | public function getStatsByCategoryCode($categoryCode) | |
| 224 | |||
| 225 | /** | ||
| 226 | * Get Stats by Category Desc. | ||
| 227 | * | ||
| 228 | * @return Array of Statistics. | ||
| 229 | */ | ||
| 230 | View Code Duplication | public function getStatsByCategoryDesc($categoryDesc) | |
| 240 | |||
| 241 | /** | ||
| 242 | * Get Stats by Segment Type. | ||
| 243 | * | ||
| 244 | * @return Array of Statistics. | ||
| 245 | */ | ||
| 246 | public function getStatsBySegmentType($segmentType) | ||
| 256 | |||
| 257 | /** | ||
| 258 | * Search Stats by Note. | ||
| 259 | * | ||
| 260 | * @return Array of Statistics. | ||
| 261 | */ | ||
| 262 | public function searchStatsByNote($note) | ||
| 272 | |||
| 273 | /** | ||
| 274 | * Search Stats by Type Code. | ||
| 275 | * | ||
| 276 | * @return Array of Statistics. | ||
| 277 | */ | ||
| 278 | View Code Duplication | public function searchStatsByTypeCode($typeCode) | |
| 288 | |||
| 289 | /** | ||
| 290 | * Search Stats by Type Code. | ||
| 291 | * | ||
| 292 | * @return Array of Statistics. | ||
| 293 | */ | ||
| 294 | View Code Duplication | public function searchStatsByTypeDesc($typeDesc) | |
| 304 | |||
| 305 | /** | ||
| 306 | * Search Stats by Type Code. | ||
| 307 | * | ||
| 308 | * @return Array of Statistics. | ||
| 309 | */ | ||
| 310 | View Code Duplication | public function searchStatsByCategoryCode($categoryCode) | |
| 320 | |||
| 321 | /** | ||
| 322 | * Search Stats by Type Code. | ||
| 323 | * | ||
| 324 | * @return Array of Statistics. | ||
| 325 | */ | ||
| 326 | View Code Duplication | public function searchStatsByCategoryDesc($categoryDesc) | |
| 336 | |||
| 337 | } | ||
| 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.