Complex classes like Filterer 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 Filterer, and based on these observations, apply Extract Interface, too.
1 | <?php |
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13 | class Filterer |
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14 | { |
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15 | /** |
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16 | * @var array |
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17 | */ |
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18 | private $uniqueNameToQueryFieldMap; |
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19 | |||
20 | /** |
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21 | * Apply the filters to the query builders |
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22 | * |
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23 | * @param QueryBuilder $queryBuilder |
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24 | * @param Filter $filterDefinition |
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25 | * @param array $uniqueNameToQueryFieldMap |
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26 | * |
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27 | * @return QueryBuilder |
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28 | * @throws \Exception |
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29 | */ |
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30 | public function filter(QueryBuilder $queryBuilder, Filter $filterDefinition, $uniqueNameToQueryFieldMap) |
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40 | |||
41 | /** |
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42 | * Builds a filter group and, recursively, constructs a tree of conditions for the filters |
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43 | * |
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44 | * @param QueryBuilder $queryBuilder |
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45 | * @param Filter $filterDefinition |
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46 | * |
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47 | * @throws \Exception |
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48 | * @return Andx|Orx |
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49 | */ |
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50 | private function buildFilterGroup(QueryBuilder $queryBuilder, Filter $filterDefinition) |
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67 | |||
68 | /** |
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69 | * @param Composite $expressions |
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70 | * @param Filter $filterDefinition |
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71 | * @param QueryBuilder $queryBuilder |
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72 | * |
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73 | * @throws \Exception |
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74 | */ |
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75 | private function addExpressionsForFilter(Composite $expressions, Filter $filterDefinition, QueryBuilder $queryBuilder) |
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86 | |||
87 | /** |
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88 | * @param Composite $expressions |
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89 | * @param FilterCondition $filterCondition |
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90 | * @param QueryBuilder $queryBuilder |
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91 | * |
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92 | * @throws \Exception |
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93 | */ |
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94 | private function addExpressionsForFilterCondition(Composite $expressions, FilterCondition $filterCondition, QueryBuilder $queryBuilder) |
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103 | |||
104 | /** |
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105 | * @param FilterCondition $filterCondition |
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106 | * @param QueryBuilder $queryBuilder |
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107 | * |
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108 | * @return string |
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109 | */ |
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110 | private function buildUniqueToken(FilterCondition $filterCondition, QueryBuilder $queryBuilder) |
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116 | |||
117 | /** |
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118 | * @param FilterCondition $filterCondition |
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119 | * @param string $token |
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120 | * @param QueryBuilder $queryBuilder |
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121 | * |
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122 | * @throws \Exception |
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123 | * |
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124 | * @return Expr|string |
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125 | */ |
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126 | private function buildExpression(FilterCondition $filterCondition, $token, QueryBuilder $queryBuilder) |
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166 | |||
167 | /** |
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168 | * @param FilterCondition $filterCondition |
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169 | * @param string $identifier |
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170 | * @param QueryBuilder $queryBuilder |
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171 | * |
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172 | * @return Andx|Orx |
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173 | * |
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174 | * @throws \Exception |
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175 | */ |
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176 | private function buildExpressionForNullValue(FilterCondition $filterCondition, $identifier, QueryBuilder $queryBuilder) |
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206 | |||
207 | /** |
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208 | * @param FilterCondition $filterCondition |
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209 | * @param string $identifier |
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210 | * @param string $token |
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211 | * @param QueryBuilder $queryBuilder |
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212 | * |
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213 | * @return Andx|Orx|string |
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214 | * |
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215 | * @throws \Exception |
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216 | */ |
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217 | private function buildExpressionForCollection(FilterCondition $filterCondition, $identifier, $token, QueryBuilder $queryBuilder) |
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240 | |||
241 | /** |
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242 | * @param FilterCondition $filterCondition |
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243 | * @param string $token |
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244 | * @param QueryBuilder $queryBuilder |
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245 | */ |
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246 | private function setExpressionParameters(FilterCondition $filterCondition, $token, QueryBuilder $queryBuilder) |
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267 | } |
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268 |