TYPO3 /
Fluid
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 AbstractConditionViewHelper 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 AbstractConditionViewHelper, and based on these observations, apply Extract Interface, too.
| 1 | <?php |
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| 37 | abstract class AbstractConditionViewHelper extends AbstractViewHelper implements NodeFilterInterface |
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| 38 | { |
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| 39 | |||
| 40 | /** |
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| 41 | * @var boolean |
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| 42 | */ |
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| 43 | protected $escapeOutput = false; |
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| 44 | |||
| 45 | /** |
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| 46 | * Initializes the "then" and "else" arguments |
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| 47 | */ |
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| 48 | public function initializeArguments() |
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| 53 | |||
| 54 | /** |
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| 55 | * Renders <f:then> child if $condition is true, otherwise renders <f:else> child. |
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| 56 | * Method which only gets called if the template is not compiled. For static calling, |
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| 57 | * the then/else nodes are converted to closures and condition evaluation closures. |
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| 58 | * |
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| 59 | * @return string the rendered string |
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| 60 | * @api |
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| 61 | */ |
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| 62 | public function render() |
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| 69 | |||
| 70 | /** |
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| 71 | * @param array $arguments |
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| 72 | * @param \Closure $renderChildrenClosure |
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| 73 | * @param RenderingContextInterface $renderingContext |
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| 74 | * @return mixed |
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| 75 | */ |
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| 76 | public static function renderStatic(array $arguments, \Closure $renderChildrenClosure, RenderingContextInterface $renderingContext) |
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| 93 | |||
| 94 | /** |
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| 95 | * Static method which can be overridden by subclasses. If a subclass |
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| 96 | * requires a different (or faster) decision then this method is the one |
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| 97 | * to override and implement. |
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| 98 | * |
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| 99 | * @param array $arguments |
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| 100 | * @param RenderingContextInterface $renderingContext |
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| 101 | * @return bool |
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| 102 | */ |
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| 103 | public static function verdict(array $arguments, RenderingContextInterface $renderingContext) |
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| 107 | |||
| 108 | /** |
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| 109 | * Static method which can be overridden by subclasses. If a subclass |
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| 110 | * requires a different (or faster) decision then this method is the one |
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| 111 | * to override and implement. |
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| 112 | * |
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| 113 | * Note: method signature does not type-hint that an array is desired, |
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| 114 | * and as such, *appears* to accept any input type. There is no type hint |
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| 115 | * here for legacy reasons - the signature is kept compatible with third |
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| 116 | * party packages which depending on PHP version would error out if this |
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| 117 | * signature was not compatible with that of existing and in-production |
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| 118 | * subclasses that will be using this base class in the future. Let this |
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| 119 | * be a warning if someone considers changing this method signature! |
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| 120 | * |
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| 121 | * @deprecated Deprecated in favor of ClassName::verdict($arguments, renderingContext), will no longer be called in 3.0 |
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| 122 | * @param array|NULL $arguments |
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| 123 | * @return boolean |
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| 124 | * @api |
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| 125 | */ |
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| 126 | protected static function evaluateCondition($arguments = null) |
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| 130 | |||
| 131 | /** |
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| 132 | * @param array $closures |
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| 133 | * @param array $conditionClosures |
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| 134 | * @param RenderingContextInterface $renderingContext |
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| 135 | * @return string |
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| 136 | */ |
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| 137 | private static function evaluateElseClosures(array $closures, array $conditionClosures, RenderingContextInterface $renderingContext) |
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| 150 | |||
| 151 | /** |
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| 152 | * Returns value of "then" attribute. |
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| 153 | * If then attribute is not set, iterates through child nodes and renders ThenViewHelper. |
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| 154 | * If then attribute is not set and no ThenViewHelper and no ElseViewHelper is found, all child nodes are rendered |
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| 155 | * |
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| 156 | * @return mixed rendered ThenViewHelper or contents of <f:if> if no ThenViewHelper was found |
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| 157 | * @api |
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| 158 | */ |
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| 159 | protected function renderThenChild() |
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| 184 | |||
| 185 | /** |
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| 186 | * Returns value of "else" attribute. |
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| 187 | * If else attribute is not set, iterates through child nodes and renders ElseViewHelper. |
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| 188 | * If else attribute is not set and no ElseViewHelper is found, an empty string will be returned. |
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| 189 | * |
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| 190 | * @return string rendered ElseViewHelper or an empty string if no ThenViewHelper was found |
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| 191 | * @api |
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| 192 | */ |
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| 193 | protected function renderElseChild() |
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| 218 | |||
| 219 | /** |
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| 220 | * Condition ViewHelpers disallow child nodes that consist purely of whitespace, |
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| 221 | * thus avoiding whitespace in output inside f:if structures but not inside any |
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| 222 | * f:then or f:else nodes. |
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| 223 | * |
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| 224 | * @param NodeInterface $node |
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| 225 | * @return bool |
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| 226 | */ |
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| 227 | View Code Duplication | public function allowsChildNodeType(NodeInterface $node): bool |
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| 234 | |||
| 235 | /** |
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| 236 | * The compiled ViewHelper adds two new ViewHelper arguments: __thenClosure and __elseClosure. |
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| 237 | * These contain closures which are be executed to render the then(), respectively else() case. |
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| 238 | * |
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| 239 | * @param string $argumentsName |
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| 240 | * @param string $closureName |
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| 241 | * @param string $initializationPhpCode |
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| 242 | * @param ViewHelperNode $node |
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| 243 | * @param TemplateCompiler $compiler |
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| 244 | * @return string |
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| 245 | */ |
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| 246 | public function compile($argumentsName, $closureName, &$initializationPhpCode, ViewHelperNode $node, TemplateCompiler $compiler) |
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| 275 | } |
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| 276 |
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Let’s assume you have a class which uses late-static binding:
}
The code above will run fine in your PHP runtime. However, if you now create a sub-class and call the
getSomeVariable()on that sub-class, you will receive a runtime error:In the case above, it makes sense to update
SomeClassto useselfinstead: