Idea for a Factory abstract class

gistfile1.aw

interface FactoryInterface {
    public static function factory($classname, $options = null);
    public static function validate($classname);
    public static function getClassMap();
}

abstract class AbstractFactory {
       
    public static function factory($name, $options = null)
    {
        if (!is_string($name)) {
            throw new Exception\InvalidArgumentException(sprintf(
                'Expecting a string, received "%s"',
                (is_object($name) ? get_class($name) : gettype($name))
            ));
        }
        $class = self::validate($name);
        if ($class === false) {
            return false;
        }
        if (!class_exists($class)) {
            return false;
        }
        return new $class($options);
    }
    
    public static function validate($name)
    {
        $classMap = static::getClassMap();
        if (array_key_exists($name, $classMap)) {
            if (is_array($classMap[$name])) {
                $classname = $classMap[$name][0];
                $interface = $classMap[$name][1];
                if (in_array($interface, class_implements($classname))) {
                    return $classname;
                } else {
                    throw new Exception\RuntimeException("The class $classname doesn't implement $interface");
                }
            }
            return $classMap[$name];
        }
        throw new Exception\RuntimeException("I cannot load the class $name");
    }
    
}

class Foo { 
    public function hello() {
        echo "Hello world!\n";
    }
}

class FooFactory extends AbstractFactory implements FactoryInterface {
    public static function getClassMap()
    {
        return array (
            'foo' => 'Foo' // if the value is array($class, $interface) the $class must implement the $interface
        );
    }
}

$foo = FooFactory::factory('foo');
if (!$foo instanceof Foo) {
    die("ERROR\n");
}
$foo->hello();