What is the Symfony2 equivalent of components in Symfony1?

I did some more research, and the simplest way I found was just this simple line in the template:

{% render 'MyBundle:MyController:myAction' %}

This outputs the result of the action, with the template specified by the action.

You can create Twig Extension with function widget and register it in the container. Also inject Kernel into this extension.

class WidgetFactoryExtension extends \Twig_Extension{    protected $kernel;    public function __construct($kernel)    {        $this->kernel= $kernel;    }    public function getFunctions()    {        return array(            'widget' => new \Twig_Function_Method($this, 'createWidget', array('is_safe' => array('html'))),        );    }    public function createWidget($name, array $options = array())    {        list($bundle, $widget) = explode(':', $name);        $widgetClass = $this->kernel->getBundle($bundle)->getNamespace() . '\\Widget\\' . $widget;        $widgetObj = new $widgetClass();        $widgetObj->setContainer($this->kernel->getContainer());        if ($options) {            $widgetObj->setOptions($options);        }        return $widgetObj;    }}

And after this write in templates:

{{ widget('QuestionsBundle:LastAnswers', {'answersCount' : 10}) }}{# class QuestionsBundle/Widget/LastAnswers #}