.. include:: /Includes.rst.txt .. index:: Events; EvaluateModifierFunctionEvent .. _EvaluateModifierFunctionEvent: ============================= EvaluateModifierFunctionEvent ============================= .. versionadded:: 12.0 This event is a substitution of the :php:`$GLOBALS['TYPO3_CONF_VARS']['SC_OPTIONS']['t3lib/class.t3lib_tsparser.php']['preParseFunc']` hook. The PSR-14 event :php:`\TYPO3\CMS\Core\TypoScript\AST\Event\EvaluateModifierFunctionEvent` allows custom TypoScript functions using the :typoscript:`:=` operator. Example ======= A simple TypoScript example looks like this: .. code-block:: typoscript :caption: EXT:my_extension/Configuration/TypoScript/setup.typoscript someIdentifier = originalValue someIdentifier := myModifierFunction(myFunctionArgument) To implement :typoscript:`myModifierFunction`, an extension needs to register an event listener in an extension's :file:`Services.yaml`: .. literalinclude:: _EvaluateModifierFunctionEvent/_Services.yaml :language: yaml :caption: EXT:my_extension/Configuration/Services.yaml Read :ref:`how to configure dependency injection in extensions `. The corresponding event listener class could look like this: .. literalinclude:: _EvaluateModifierFunctionEvent/_MyEventListener.php :language: php :caption: EXT:my_extension/Classes/TypoScript/EventListener/MyEventListener.php API === .. include:: /CodeSnippets/Events/Core/EvaluateModifierFunctionEvent.rst.txt