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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35 | class CacheFileStorage |
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36 | { |
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37 | /** |
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38 | * @var Storage |
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39 | */ |
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40 | private $storage; |
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41 | |||
42 | /** |
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43 | * @var JsonConverter |
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44 | */ |
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45 | private $converter; |
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46 | |||
47 | /** |
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48 | * Creates a new storage. |
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49 | * |
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50 | * @param Storage $storage The file storage. |
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51 | * @param JsonConverter $converter The cache file converter. |
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52 | * @param JsonEncoder $jsonEncoder The JSON encoder. |
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53 | * @param JsonDecoder $jsonDecoder The JSON decoder. |
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54 | */ |
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55 | 1 | public function __construct( |
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67 | |||
68 | /** |
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69 | * Loads a cache file from a file path. |
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70 | * |
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71 | * @param string $path The path to the cache file. |
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72 | * |
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73 | * @return CacheFile The loaded cache file. |
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74 | * |
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75 | * @throws FileNotFoundException If the file does not exist. |
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76 | * @throws ReadException If the file cannot be read. |
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77 | * @throws InvalidConfigException If the file contains invalid |
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78 | * configuration. |
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79 | */ |
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80 | public function loadCacheFile($path) |
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97 | |||
98 | /** |
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99 | * Saves a cache file. |
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100 | * |
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101 | * The cache file is saved to the same path that it was read from. |
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102 | * |
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103 | * @param CacheFile $cacheFile The cache file to save. |
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104 | * |
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105 | * @throws WriteException If the file cannot be written. |
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106 | */ |
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107 | public function saveCacheFile(CacheFile $cacheFile) |
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114 | |||
115 | /** |
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116 | * Returns whether a cache file exists. |
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117 | * |
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118 | * @param string $path The cache file path. |
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119 | * |
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120 | * @return bool Returns `true` if the cache file exists and `false` otherwise. |
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121 | */ |
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122 | public function fileExists($path) |
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126 | |||
127 | View Code Duplication | private function encode(stdClass $jsonData, $path) |
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139 | |||
140 | View Code Duplication | private function decode($json, $path) |
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152 | } |
In PHP it is possible to write to properties without declaring them. For example, the following is perfectly valid PHP code:
Generally, it is a good practice to explictly declare properties to avoid accidental typos and provide IDE auto-completion: