Create an Embedded Controller¶

Start by adding a new controller function that queries for upcoming events, and renders a template. So far, this feels like any other controller, except it doesn’t have a route:

// src/Yoda/EventBundle/Controller/EventController.php
// ...

public function _upcomingEventsAction()
{
    $em = $this->getDoctrine()->getManager();

    $events = $em->getRepository('EventBundle:Event')
        ->getUpcomingEvents()
    ;

    return $this->render('EventBundle:Event:_upcomingEvents.html.twig', array(
        'events' => $events,
    ));
}

Create the template and grab the event-rendering code from index.html.twig. But hey, don’t extend the base layout. This controller is meant to just render “part” of a page, not the entire HTML body. I also need to rename entities to events, since that’s how I called the variable in the controller:

{# src/Yoda/EventBundle/Resources/views/Event/_upcomingEvents.html.twig #}
{% for event in events %}
    <article>
        <header class="map-container">
            <img src="http://maps.googleapis.com/maps/api/staticmap?center={{ event.location | url_encode }}&markers=color:red%7Ccolor:red%7C{{ event.location | url_encode }}&zoom=14&size=150x150&maptype=roadmap&sensor=false" />
        </header>
        <section>
            <h3>
                <a href="{{ path('event_show', {'slug': event.slug}) }}">{{ event.name }}</a>
            </h3>

            <dl>
                <dt>where:</dt>
                <dd>{{ event.location }}</dd>

                <dt>when:</dt>
                <dd>{{ event.time | date('g:ia / l M j, Y') }}</dd>

                <dt>who:</dt>
                <dd>Todo # of people</dd>
            </dl>
        </section>
    </article>
{% endfor %}

The new controller prints just a list of events, without a layout. We didn’t give it a route, but we don’t need to: we’re going to call it straight from Twig.

Oh, and what’s up with the underscore in front of the name? That’s just a standard I follow for controllers that render partial pages.

Getting render-happy in Twig¶

Ok, now I’ll show you the power behind this render weapon. Remove the query in indexAction and pass nothing into the template:

// src/Yoda/EventBundle/Controller/EventController.php
// ...

/**
 * @Template()
 * @Route("/", name="event")
 */
public function indexAction()
{
    return array();
}

Next, remove the big entities for loop that we just copied from index.html.twig and replace it with the render function:

{% extends 'EventBundle::layout.html.twig' %}

{% block body %}
    <section class="events">
        {# same <header> stuff as before #}
        {# ... #}

        {{ render(controller('EventBundle:Event:_upcomingEvents')) }}
    </section>
{% endblock %}

Try out the homepage in the dev environment. Hey, it looks just like before! render calls our controller, we build a partial HTML page, and then it gets printed. This handy function is great for re-using page chunks and is also key to using Symfony’s Caching.

Using render in the Error Template¶

Our goal was to list upcoming events on the 404 page. Well, that’s pretty easy now:

{# app/Resources/TwigBundle/views/Exception/error404.html.twig #}
{# ... #}

{% block body %}
    {# existing <section> ... #}

    <section class="events">
        {{ render(controller('EventBundle:Event:_upcomingEvents')) }}
    </section>
{% endblock %}

Move to an imaginary page in your prod environment. In other words, put the app.php back in the URL:

http://localhost:9000/app.php/foo

Ah, but don’t forget to clear your cache!

php app/console cache:clear --env=prod

Controller Arguments¶

Great! Now what if we wanted to show a different number of upcoming events on the homepage versus the error page? No problem: render let’s us pass arguments to the controller function. Pass a max argument of 1 from the error template:

{# app/Resources/TwigBundle/views/Exception/error404.html.twig #}
{# ... #}

<section class="events">
    {{ render(controller('EventBundle:Event:_upcomingEvents', {
        'max': 1
    })) }}
</section>

Next, add a $max argument to _upcomingEventsAction and give it a default value so that we don’t have to pass it in. Send this variable into the getUpcomingEvents() function:

// src/Yoda/EventBundle/Controller/EventController.php
// ...

public function _upcomingEventsAction($max = null)
{
    $em = $this->getDoctrine()->getManager();

    $events = $em->getRepository('EventBundle:Event')
        ->getUpcomingEvents($max)
    ;

    return $this->render('EventBundle:Event:_upcomingEvents.html.twig', array(
        'events' => $events,
    ));
}

In EventRepository, give the function a $max argument. Instead of returning immediately, set the query builder to a variable and then return it later. If $max is set, limit the number of results that will be returned:

// src/Yoda/EventBundle/Entity/EventRepository.php
// ...

public function getUpcomingEvents($max = null)
{
    $qb = $this
        ->createQueryBuilder('e')
        ->addOrderBy('e.time', 'ASC')
        ->andWhere('e.time > :now')
        ->setParameter('now', new \DateTime());

    if ($max) {
        $qb->setMaxResults($max);
    }

    return $qb
        ->getQuery()
        ->execute()
    ;
}

Clear your cache and then try it out. Hey, only 1 event! Not only can render call a controller, but we can control its arguments. Now you’re unstoppable.