GenericSingleton in PHP

GenericSingleton.php

<?php

class A1 {

    /**
     * @var array
     */
    private static $instanceDictionary = array();

    /**
     * @return self
     */
    public static function getInstance()
    {
        $calledClass = get_called_class();
        $dictionary = self::$instanceDictionary;
        if(!array_key_exists($calledClass, $dictionary)) {
            
            $reflectionClass = new \ReflectionClass($calledClass);
            $reflectionMethod = $reflectionClass->getMethod('createInstance');
            $reflectionMethod->setAccessible(true);
            $dictionary[$calledClass] = $reflectionMethod->invokeArgs(
                null, func_get_args()
            );
            
            self::$instanceDictionary = $dictionary;
        }

        return $dictionary[$calledClass];
    }

    /**
     * @return self
     */
    public static function createInstance()
    {
        var_dump('create '.get_called_class());
        $className = get_called_class();

        return new $className();
    }

    public $x1 = 10;
    
    /**
     *  thx. to radmen
     **/
    protected function __construct()
    {
    }
}

class A2 extends A1 {

    /**
     * Just to fix type hinting issues. otherwiese my PHPStorm ide assumes it to be A1 type
     * @return self
     */
    public static function getInstance()
    {
        return parent::getInstance();
    }

    public $x2 = 10;
}

class A3 extends A2 {
    
    /**
     * Just to fix type hinting issues. otherwiese my PHPStorm ide assumes it to be A1 type
     * @return self
     */
    public static function getInstance()
    {
        return parent::getInstance();
    }
    public $x3 = 10;
    public $x1 = 5;

}



$a1 = A1::getInstance();
$a2 = A2::getInstance();
$a3 = A3::getInstance();

$a1 = A1::getInstance();
$a2 = A2::getInstance();
$a3 = A3::getInstance();

var_dump($a1);
var_dump($a2);
var_dump($a3);

exit;

good job