favorites.html.twig

{% extends "AppBundle::base.html.twig" %}
{% block title %}Something{% endblock %}
{% block body %}
	<h1>Favorites</h1>
  <p>Here are you favorites.</p>
  <div id="favorites-container">
    {% include "AppBundle:user:favorites_list.html.twig" %}
  </div>
  
  <button id="load-btn">Next Page</button>
{% endblock %}
{% block javascripts %}
  {{ parent() }}
	<script type="text/javascript">
		$("#load-btn").on("click", function() {
		    fetch('/u/headzoo/favorites')
          .then(function(resp) {
            $('#favorites-container').html(resp);
          });
		});
	</script>
{% endblock %}

favorites_list.html.twig

<ul>
  {% for e in events %}
    <li>{{ e }}</li>
  {% endfor %}
</ul>

UserController.php

<?php
class UserController extends Controller
{
  /**
   * @Route("/u/{username}/favorites", name="profile_favorites")
   *
   * @param string $username
   * @return Response
   */
  public function favoritesAction(Request $request, $username)
  {
    $em = $this->getDoctrine()->getManager();
    $user = $this->findUserOrThrow($username);
    
    // Get the last 25 videos the user favorited.
    $events = $em->getRepository("AppBundle:Favorite")
      ->findByUser($user, 25);
    
    // For ajax requests, send the list of favorites as a "snippet" of html.
    if ($request->isXmlHttpRequest()) {
      return $this->render("AppBundle:user:favorites_list.html.twig", [
        "user"   => $user,
        "events" => $events
      ]);
      
    // Otherwise send the whole page.
    } else {
      return $this->render("AppBundle:user:favorites.html.twig", [
        "user"   => $user,
        "events" => $events
      ]);
    }
  }
}