"Optional singleton" pattern

optional singleton pattern.php

<?php
// See also http://en.mnapoli.fr/the-optional-singleton-pattern/

class MyService
{
    private static $singletonInstance = null;
    
    /**
     * Keep the constructor public
     */
    public function __construct() {
    }

    /**
     * Returns an instance of the class (Singleton design pattern)
     * @return MyService
     */
    public static function getInstance() {
        if (self::$singletonInstance === null) {
            self::$singletonInstance = new self();
        }
        return self::$singletonInstance;
    }

}

// Singleton usage
$myService = MyService::getInstance();

// Classic usage
$myService = new MyService();