Attention

TYPO3 v8 has reached its end-of-life March 31st, 2020 and is not maintained by the community anymore.

You can order Extended Long Term Support (ELTS) here: TYPO3 ELTS.

Singletons

TYPO3 supports singleton patterns for classes. Singletons are instantiated only once per HTTP request regardless of the number of calls to GeneralUtility::makeInstance(). To use a singleton pattern, a class must implement the SingletonInterface:

namespace Vendor\MyNamespace;

class MySingletonClass implements \TYPO3\CMS\Core\SingletonInterface
{
    
}

This interface has no methods to implement.