KNP Menu Bundle with Bootstrap 3 and Font Awesome 4 (+ fixed several bugs)

index.html.twig

{% extends '::base.html.twig' %}

{% block title %}My Awesome Page!{% endblock %}

{% block stylesheets %}	
	<link rel="stylesheet" href="//netdna.bootstrapcdn.com/bootstrap/3.1.1/css/bootstrap.min.css">
	<link rel="stylesheet" href="//netdna.bootstrapcdn.com/font-awesome/4.0.3/css/font-awesome.css">
{% endblock %}

{% block body %}
  <div class="navbar navbar-default navbar-fixed-top">
      <div class="container-fluid">
          {# Brand and toggle get grouped for better mobile display #}
          <div class="navbar-header">
              <button type="button" class="navbar-toggle" data-toggle="collapse" data-target="#admin-navbar-collapse-1">
                  <span class="sr-only">Toggle navigation</span>
                  <span class="icon-bar"></span>
                  <span class="icon-bar"></span>
                  <span class="icon-bar"></span>
              </button>
              <a class="navbar-brand" href="#">Awesome!</a>
          </div>

          {# Collect the nav links, forms, and other content for toggling #}
          <div class="collapse navbar-collapse" id="admin-navbar-collapse-1">
              {{ knp_menu_render('AcmeHelloBundle:MenuBuilder:mainMenu', {'currentClass': 'active', 'template': 'AcmeHelloBundle:Menu:knp_menu.html.twig'}) }}
              {{ knp_menu_render('AcmeHelloBundle:MenuBuilder:userMenu', {'currentClass': 'active', 'template': 'AcmeHelloBundle:Menu:knp_menu.html.twig'}) }}
          </div>
      </div>
  </div>
	<div class="content" style="margin-top: 60px;">
		Content goes here!
	</div>	 
{% endblock %}

{% block javascripts %}
	<script src="//ajax.googleapis.com/ajax/libs/jquery/1.8.1/jquery.min.js"></script>
	<script type="text/javascript" src="//netdna.bootstrapcdn.com/bootstrap/3.1.1/js/bootstrap.min.js"></script>
{% endblock %}

knp_menu.html.twig

{% extends '@KnpMenu/menu.html.twig' %}
{% import 'knp_menu.html.twig' as macros %}

{% block item %}
    {% if item.displayed %}
        {%- set attributes = item.attributes %}
        {%- set is_dropdown = item.getExtra('dropdown', false) %}
        {%- set icon = item.getExtra('icon') %}

        {%- if item.getExtra('divider_prepend') %}
            {{ block('dividerElement') }}
        {%- endif %}

        {# building the class of the item #}
        {%- set classes = item.attribute('class') is not empty ? [item.attribute('class')] : [] %}
        {%- if matcher.isCurrent(item) %}
            {%- set classes = classes|merge([options.currentClass]) %}
        {%- elseif matcher.isAncestor(item, options.depth) %}
            {%- set classes = classes|merge([options.ancestorClass]) %}
        {%- endif %}
        {%- if item.actsLikeFirst %}
            {%- set classes = classes|merge([options.firstClass]) %}
        {%- endif %}
        {%- if item.actsLikeLast %}
            {%- set classes = classes|merge([options.lastClass]) %}
        {%- endif %}

        {# building the class of the children #}
        {%- set childrenClasses = item.childrenAttribute('class') is not empty ? [item.childrenAttribute('class')] : [] %}
        {%- set childrenClasses = childrenClasses|merge(['menu_level_' ~ item.level]) %}

        {# adding classes for dropdown #}
        {%- if is_dropdown %}
            {%- set classes = classes|merge(['dropdown']) %}
            {%- set childrenClasses = childrenClasses|merge(['dropdown-menu']) %}
        {%- endif %}

        {# putting classes together #}
        {%- if classes is not empty %}
            {%- set attributes = attributes|merge({'class': classes|join(' ')}) %}
        {%- endif %}
        {%- set listAttributes = item.childrenAttributes|merge({'class': childrenClasses|join(' ') }) %}

        {# displaying the item #}
        <li{{ macros.attributes(attributes) }}>
            {%- if is_dropdown %}
                {{- block('dropdownElement') }}
            {%- elseif item.uri is not empty and (not item.current or options.currentAsLink) %}
                {{- block('linkElement') }}
            {%- else %}
                {{- block('spanElement') }}
            {%- endif %}
            {# render the list of children#}
            {{ block('list') }}
        </li>

        {%- if item.getExtra('divider_append') %}
            {{ block('dividerElement') }}
        {%- endif %}
    {% endif %}
{% endblock %}

{% block dividerElement %}
    {% if item.level == 1 %}
        <li class="divider-vertical"></li>
    {% else %}
        <li class="divider"></li>
    {% endif %}
{% endblock %}

{% block linkElement %}
    <a href="{{ item.uri }}"{{ macros.attributes(item.linkAttributes) }}>
        {%- if icon is not empty %}
            <i class="{{ icon }}"></i>
        {% endif %}
        {{- block('label') -}}
    </a>
{% endblock %}

{% block spanElement %}
    <span{{ macros.attributes(item.labelAttributes) }}>
        {%- if icon is not empty %}
            <i class="{{ icon }}"></i>
        {% endif %}
        {{- block('label') -}}
	</span>
{% endblock %}

{% block dropdownElement %}
    {%- set classes = item.linkAttribute('class') is not empty ? [item.linkAttribute('class')] : [] %}
    {%- set classes = classes|merge(['dropdown-toggle']) %}
    {%- set attributes = item.linkAttributes %}
    {%- set attributes = attributes|merge({'class': classes|join(' ')}) %}
    {%- set attributes = attributes|merge({'data-toggle': 'dropdown'}) %}
    <a href="#"{{ macros.attributes(attributes) }}>
        {%- if icon is not empty %}
            <i class="{{ icon }}"></i>
        {% endif %}
        {{- block('label') }}
        <b class="caret"></b>
    </a>
{% endblock %}

MenuBuilder.php

<?php

namespace Acme\HelloBundle\Menu;

use Knp\Menu\FactoryInterface;
use Symfony\Component\DependencyInjection\ContainerAware;

class MenuBuilder extends ContainerAware
{
    public function mainMenu(FactoryInterface $factory, array $options)
    {
        $menu = $factory->createItem('root');
        $menu->setChildrenAttribute('class', 'nav navbar-nav');

        $menu->addChild('Projects', array('route' => 'acme_hello_projects'))
            ->setExtra('icon', 'fa fa-list');

        $menu->addChild('Employees', array('route' => 'acme_hello_employees'))
            ->setExtra('icon', 'fa fa-group');

        return $menu;
    }

    public function userMenu(FactoryInterface $factory, array $options)
    {
        $menu = $factory->createItem('root');
        $menu->setChildrenAttribute('class', 'nav navbar-nav navbar-right');

        /*
        You probably want to show user specific information such as the username here. That's possible! Use any of the below methods to do this.

        if($this->container->get('security.context')->isGranted(array('ROLE_ADMIN', 'ROLE_USER'))) {} // Check if the visitor has any authenticated roles
        $username = $this->container->get('security.context')->getToken()->getUser()->getUsername(); // Get username of the current logged in user

        */
        $menu->addChild('User', array('label' => 'Hi visitor'))
            ->setExtras(array(
                'dropdown' => true,
                'icon' => 'fa fa-user',
            ));

        $menu['User']->addChild('Edit profile', array('route' => 'acme_hello_profile'))
            ->setExtra('icon', 'fa fa-edit');

        return $menu;
    }
}

RequestVoter.php

<?php

namespace Acme\HelloBundle\Menu;

use Knp\Menu\ItemInterface;
use Knp\Menu\Matcher\Voter\VoterInterface;
use Symfony\Component\DependencyInjection\ContainerInterface;

class RequestVoter implements VoterInterface
{

    private $container;

    public function __construct(ContainerInterface $container)
    {
        $this->container = $container;
    }

    public function matchItem(ItemInterface $item)
    {
    	if ($item->getUri() === $this->container->get('request')->getRequestUri()) {
    		// URL's completely match
            return true;
        } else if($item->getUri() !== $this->container->get('request')->getBaseUrl().'/' && (substr($this->container->get('request')->getRequestUri(), 0, strlen($item->getUri())) === $item->getUri())) {
        	// URL isn't just "/" and the first part of the URL match
	    	return true;
    	}
        return null;
    }

}

services.yml

services:
    acme.hello.menu.voter.request:
        class: Acme\HelloBundle\Menu\RequestVoter
        arguments:
            - @service_container
        tags:
            - { name: knp_menu.voter }

In > Symfony3.2 you should use the ContainerAwareTrait because Symfony\Component\DependencyInjection\ContainerAware is not supported anymore. Thanks for sharing.

Replace:
use Symfony\Component\DependencyInjection\ContainerAware;
with:
use Symfony\Component\DependencyInjection\ContainerAwareTrait;
and then add the trait in the class itself:
use ContainerAwareTrait;

Thank you for providing that. Can you please explain why the RequestVoter is needed?

Dropdown is supported by using:

$username = $this->tokenStorage->getToken()->getUsername();

$menu->addChild($username, [
    'extras' => [
        'dropdown' => true,
    ]
]);
$menu[$username]->addChild('Logout', array(
    'route' => 'fos_user_security_logout'
));