KNP Menu Bundle with Bootstrap 3 and Font Awesome 4 (see http://bit.ly/1sd1rJr , thanks to Niels Mouthaan!)

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 'knp_menu.html.twig' %}

{% block item %}
{% import "knp_menu.html.twig" as macros %}
{% if item.displayed %}
    {%- set attributes = item.attributes %}
    {%- set is_dropdown = attributes.dropdown|default(false) %}
    {%- set divider_prepend = attributes.divider_prepend|default(false) %}
    {%- set divider_append = attributes.divider_append|default(false) %}

{# unset bootstrap specific attributes #}
    {%- set attributes = attributes|merge({'dropdown': null, 'divider_prepend': null, 'divider_append': null }) %}

    {%- if 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 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 item.attribute('icon') is not empty  %}
    		<i class="{{ item.attribute('icon') }}"></i> 
    	{% endif %}
		{{ block('label') }}
	</a>
{% endblock %}

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

{% block label %}{{ item.label|trans }}{% 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'))
			->setAttribute('icon', 'fa fa-list');

		$menu->addChild('Employees', array('route' => 'acme_hello_employees'))
			->setAttribute('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'))
			->setAttribute('dropdown', true)
			->setAttribute('icon', 'fa fa-user');

		$menu['User']->addChild('Edit profile', array('route' => 'acme_hello_profile'))
			->setAttribute('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 }