public function getComponentFactory($tagName)
    {
        //check for alias first
        if(isset($this->alias[$tagName])) {
            $tagName = $this->alias[$tagName];
        }

        if(
            isset($this->componentFactory[$tagName])
            && $this->componentFactory[$tagName] instanceof ComponentFactoryInterface
        ) {
            return $this->componentFactory[$tagName];
        }

        return null;
    }