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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| 8 | class MetadataManager |
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| 9 | { |
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| 10 | private $V3Edmx = null; |
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| 11 | private $oldEdmx = null; |
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| 12 | private $lastError = null; |
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| 13 | private $serializer = null; |
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| 14 | |||
| 15 | public function __construct($namespaceName = "Data", $containerName = "DefaultContainer") |
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| 27 | |||
| 28 | public function getEdmx() |
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| 32 | |||
| 33 | public function getEdmxXML() |
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| 37 | |||
| 38 | public function addEntityType($name, $accessType = "Public") |
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| 65 | |||
| 66 | private function startEdmxTransaction() |
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| 70 | |||
| 71 | /** |
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| 72 | * Pluralizes a word if quantity is not one. |
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| 73 | * |
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| 74 | * @param int $quantity Number of items |
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| 75 | * @param string $singular Singular form of word |
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| 76 | * @param string $plural Plural form of word; function will attempt to deduce plural form from singular if not provided |
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| 77 | * @return string Pluralized word if quantity is not one, otherwise singular |
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| 78 | */ |
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| 79 | View Code Duplication | public static function pluralize($quantity, $singular, $plural = null) |
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| 94 | |||
| 95 | private function revertEdmxTransaction() |
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| 99 | |||
| 100 | private function commitEdmxTransaction() |
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| 104 | |||
| 105 | public function addComplexType(\ReflectionClass $refClass, $name, $namespace = null, $baseResourceType = null) |
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| 109 | |||
| 110 | private function getLastError() |
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| 114 | } |
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| 115 |
PHP Analyzer performs a side-effects analysis of your code. A side-effect is basically anything that might be visible after the scope of the method is left.
Let’s take a look at an example:
If we look at the
getEmail()method, we can see that it has no side-effect. Whether you call this method or not, no future calls to other methods are affected by this. As such code as the following is useless:On the hand, if we look at the
setEmail(), this method _has_ side-effects. In the following case, we could not remove the method call: