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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23 | trait SetterTrait |
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24 | { |
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25 | /** |
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26 | * Set permission. |
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27 | * @param string $name |
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28 | * @param string $description |
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29 | * @return Item |
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30 | */ |
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31 | 11 | public function setPermission($name, $description = null) |
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41 | |||
42 | /** |
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43 | * Set role. |
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44 | * @param string $name |
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45 | * @param string $description |
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46 | * @return Item |
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47 | */ |
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48 | 10 | public function setRole($name, $description = null) |
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58 | |||
59 | /** |
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60 | * Set child. |
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61 | * @param string|Item $parent |
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62 | * @param string|Item $child |
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63 | * @return bool |
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64 | */ |
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65 | 10 | public function setChild($parent, $child) |
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87 | |||
88 | /** |
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89 | * Assigns an item (role or permission) to a user. |
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90 | * @param string|Item $item |
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91 | * @param string|integer $userId the user ID (see [[\yii\web\User::id]]) |
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92 | * @throws \Exception when given wrong item name |
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93 | * @return Assignment|null the assignment object or `null` when assignment was not found by name |
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94 | */ |
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95 | 20 | public function setAssignment($item, $userId) |
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113 | |||
114 | 20 | protected function findItem($name, $description = null) |
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126 | |||
127 | /** |
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128 | * Assigns items to a user. |
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129 | * @param string|array $items |
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130 | * @param string|integer $userId |
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131 | */ |
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132 | 10 | public function setAssignments($items, $userId) |
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141 | |||
142 | /** |
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143 | * Returns all assignments in the system. |
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144 | * @return array |
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145 | */ |
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146 | public function getAllAssignments() |
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150 | |||
151 | /** |
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152 | * Returns all items in the system. |
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153 | * @return array |
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154 | */ |
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155 | 20 | public function getAllItems() |
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159 | } |
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160 |
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.