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:
Complex classes like Autopromote often do a lot of different things. To break such a class down, we need to identify a cohesive component within that class. A common approach to find such a component is to look for fields/methods that share the same prefixes, or suffixes. You can also have a look at the cohesion graph to spot any un-connected, or weakly-connected components.
Once you have determined the fields that belong together, you can apply the Extract Class refactoring. If the component makes sense as a sub-class, Extract Subclass is also a candidate, and is often faster.
While breaking up the class, it is a good idea to analyze how other classes use Autopromote, and based on these observations, apply Extract Interface, too.
1 | <?php |
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28 | class Autopromote { |
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29 | /** |
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30 | * Get the groups for the given user based on $wgAutopromote. |
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31 | * |
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32 | * @param User $user The user to get the groups for |
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33 | * @return array Array of groups to promote to. |
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34 | */ |
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35 | public static function getAutopromoteGroups( User $user ) { |
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50 | |||
51 | /** |
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52 | * Get the groups for the given user based on the given criteria. |
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53 | * |
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54 | * Does not return groups the user already belongs to or has once belonged. |
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55 | * |
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56 | * @param User $user The user to get the groups for |
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57 | * @param string $event Key in $wgAutopromoteOnce (each one has groups/criteria) |
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58 | * |
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59 | * @return array Groups the user should be promoted to. |
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60 | * |
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61 | * @see $wgAutopromoteOnce |
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62 | */ |
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63 | public static function getAutopromoteOnceGroups( User $user, $event ) { |
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89 | |||
90 | /** |
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91 | * Recursively check a condition. Conditions are in the form |
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92 | * array( '&' or '|' or '^' or '!', cond1, cond2, ... ) |
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93 | * where cond1, cond2, ... are themselves conditions; *OR* |
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94 | * APCOND_EMAILCONFIRMED, *OR* |
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95 | * array( APCOND_EMAILCONFIRMED ), *OR* |
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96 | * array( APCOND_EDITCOUNT, number of edits ), *OR* |
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97 | * array( APCOND_AGE, seconds since registration ), *OR* |
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98 | * similar constructs defined by extensions. |
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99 | * This function evaluates the former type recursively, and passes off to |
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100 | * self::checkCondition for evaluation of the latter type. |
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101 | * |
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102 | * @param mixed $cond A condition, possibly containing other conditions |
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103 | * @param User $user The user to check the conditions against |
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104 | * @return bool Whether the condition is true |
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105 | */ |
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106 | private static function recCheckCondition( $cond, User $user ) { |
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152 | |||
153 | /** |
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154 | * As recCheckCondition, but *not* recursive. The only valid conditions |
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155 | * are those whose first element is APCOND_EMAILCONFIRMED/APCOND_EDITCOUNT/ |
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156 | * APCOND_AGE. Other types will throw an exception if no extension evaluates them. |
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157 | * |
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158 | * @param array $cond A condition, which must not contain other conditions |
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159 | * @param User $user The user to check the condition against |
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160 | * @throws MWException |
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161 | * @return bool Whether the condition is true for the user |
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162 | */ |
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163 | private static function checkCondition( $cond, User $user ) { |
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209 | } |
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210 |