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:
1 | <?php |
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21 | trait SetterTrait |
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22 | { |
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23 | /** |
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24 | * Set permission. |
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25 | * @param string $name |
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26 | * @param string $description |
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27 | * @return Item |
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28 | */ |
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29 | 8 | public function setPermission($name, $description = null) |
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39 | |||
40 | /** |
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41 | * Set role. |
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42 | * @param string $name |
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43 | * @param string $description |
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44 | * @return Item |
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45 | */ |
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46 | 8 | public function setRole($name, $description = null) |
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56 | |||
57 | /** |
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58 | * Set child. |
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59 | * @param string|Item $parent |
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60 | * @param string|Item $child |
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61 | * @return bool |
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62 | */ |
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63 | 8 | public function setChild($parent, $child) |
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85 | |||
86 | /** |
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87 | * Assigns an item (role or permission) to a user. |
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88 | * @param string|Item $item |
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89 | * @param string|integer $userId the user ID (see [[\yii\web\User::id]]) |
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90 | * @throws \Exception when given wrong item name |
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91 | * @return Assignment the assignment object |
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92 | */ |
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93 | 16 | public function setAssignment($item, $userId) |
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104 | |||
105 | 16 | protected function findItem($name, $description = null) |
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117 | |||
118 | /** |
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119 | * Assigns items to a user. |
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120 | * @param string|array $items |
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121 | * @param string|integer $userId |
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122 | */ |
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123 | 6 | public function setAssignments($items, $userId) |
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132 | |||
133 | /** |
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134 | * Returns all assignments in the system. |
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135 | * @return array |
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136 | */ |
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137 | public function getAllAssignments() |
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141 | |||
142 | /** |
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143 | * Returns all items in the system. |
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144 | * @return array |
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145 | */ |
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146 | 16 | public function getAllItems() |
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150 | } |
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151 |
This check looks for methods that are used by a trait but not required by it.
To illustrate, let’s look at the following code example
The trait
Idable
provides a methodequalsId
that in turn relies on the methodgetId()
. If this method does not exist on a class mixing in this trait, the method will fail.Adding the
getId()
as an abstract method to the trait will make sure it is available.