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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| 29 | class ForeignDBFile extends LocalFile { |
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| 30 | /** |
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| 31 | * @param Title $title |
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| 32 | * @param FileRepo $repo |
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| 33 | * @param null $unused |
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| 34 | * @return ForeignDBFile |
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| 35 | */ |
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| 36 | static function newFromTitle( $title, $repo, $unused = null ) { |
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| 39 | |||
| 40 | /** |
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| 41 | * Create a ForeignDBFile from a title |
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| 42 | * Do not call this except from inside a repo class. |
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| 43 | * |
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| 44 | * @param stdClass $row |
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| 45 | * @param FileRepo $repo |
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| 46 | * @return ForeignDBFile |
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| 47 | */ |
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| 48 | View Code Duplication | static function newFromRow( $row, $repo ) { |
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| 55 | |||
| 56 | /** |
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| 57 | * @param string $srcPath |
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| 58 | * @param int $flags |
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| 59 | * @param array $options |
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| 60 | * @return FileRepoStatus |
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| 61 | * @throws MWException |
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| 62 | */ |
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| 63 | function publish( $srcPath, $flags = 0, array $options = [] ) { |
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| 66 | |||
| 67 | /** |
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| 68 | * @param string $oldver |
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| 69 | * @param string $desc |
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| 70 | * @param string $license |
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| 71 | * @param string $copyStatus |
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| 72 | * @param string $source |
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| 73 | * @param bool $watch |
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| 74 | * @param bool|string $timestamp |
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| 75 | * @param User $user User object or null to use $wgUser |
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| 76 | * @return bool |
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| 77 | * @throws MWException |
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| 78 | */ |
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| 79 | function recordUpload( $oldver, $desc, $license = '', $copyStatus = '', $source = '', |
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| 83 | |||
| 84 | /** |
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| 85 | * @param array $versions |
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| 86 | * @param bool $unsuppress |
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| 87 | * @return FileRepoStatus |
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| 88 | * @throws MWException |
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| 89 | */ |
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| 90 | function restore( $versions = [], $unsuppress = false ) { |
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| 93 | |||
| 94 | /** |
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| 95 | * @param string $reason |
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| 96 | * @param bool $suppress |
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| 97 | * @param User|null $user |
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| 98 | * @return FileRepoStatus |
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| 99 | * @throws MWException |
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| 100 | */ |
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| 101 | function delete( $reason, $suppress = false, $user = null ) { |
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| 104 | |||
| 105 | /** |
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| 106 | * @param Title $target |
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| 107 | * @return FileRepoStatus |
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| 108 | * @throws MWException |
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| 109 | */ |
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| 110 | function move( $target ) { |
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| 113 | |||
| 114 | /** |
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| 115 | * @return string |
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| 116 | */ |
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| 117 | function getDescriptionUrl() { |
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| 121 | |||
| 122 | /** |
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| 123 | * @param bool|Language $lang Optional language to fetch description in. |
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| 124 | * @return string |
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| 125 | */ |
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| 126 | function getDescriptionText( $lang = false ) { |
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| 173 | |||
| 174 | /** |
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| 175 | * Get short description URL for a file based on the page ID. |
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| 176 | * |
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| 177 | * @return string |
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| 178 | * @throws DBUnexpectedError |
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| 179 | * @since 1.27 |
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| 180 | */ |
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| 181 | public function getDescriptionShortUrl() { |
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| 200 | |||
| 201 | } |
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| 202 |
Let’s take a look at an example:
In the above example, the authenticate() method works fine as long as you just pass instances of MyUser. However, if you now also want to pass a different sub-classes of User which does not have a getDisplayName() method, the code will break.
Available Fixes
Change the type-hint for the parameter:
Add an additional type-check:
Add the method to the parent class: