TYPO3 provides an API class for creating so-called 'Feature Toggles'. Feature toggles provide an easy way to add new implementations of features next to their legacy version. By using a feature toggle, the integrator or site admin can decide when to switch to the new feature.
The API checks against a system-wide option array within
$GLOBALS['TYPO3_CONF_VARS']['SYS']['features'] which an integrator
or admin can set in the
Both TYPO3 Core and Extensions can provide alternative functionality for a certain feature.
Examples for features are:
Throw exceptions in new code instead of just returning a string message as error message.
Disable obsolete functionality which might still be used, but slows down the system.
Enable alternative PageNotFound handling for an installation.
Naming of Feature Toggles¶
Feature names should NEVER be named "enable" or have a negation, or contain versions or years.
Core Feature Toggles¶
Some examples for feature toggles in the TYPO3 Core:
redirects.hitCount: Enables hit statistics in the redirects backend module
TypoScript.strictSyntax: If on, TypoScript is parsed in strict syntax modes. Enabling this feature means old condition syntax (which is deprecated) will trigger deprecation messages.
Enable / Disable Feature Toggle¶
Features can be toggled in the Settings module via Feature Toggles:
Internally, the changes are written to
'SYS' => [ 'features' => [ 'redirects.hitCount' => true, ], ]
Feature Toggles in TypoScript¶
To check wether a feature is enabled in TypoScript was introduced in v9.5 in forge#86881
Support for feature toggle check in the symfony expression language DefaultFunctionProvider is provided.
With the new function
feature() the feature toggle can be checked.
[feature("TypoScript.strictSyntax")] # This condition matches if the feature toggle "TypoScript.strictSyntax" is true [END] [feature("TypoScript.strictSyntax") === false] # This condition matches if the feature toggle "TypoScript.strictSyntax" is false [END]