Modified to add support for submenus.

README.md

For a recent project, I needed to include KnpMenuBundle in a Symfony2 project. This project was styled using the famous Twitter Bootstrap. I’ve found many articles describing how to do this but all of them didn’t exactly resulted in something I wanted: a web application with a navigation bar including icons and dropdown menu’s. In addition, I needed a “active” class indicating which item was visited, including parent/child items.

The files below belong to a tutorial which can be found here: http://nielsmouthaan.nl/symfony2-knpmenubundle-font-awesome-twitter-bootstrap-integration-navigation-bar-including-icons-and-dropdown-menus/

index.html.twig

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

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

{% block stylesheets %}	
	<link rel="stylesheet" href="//netdna.bootstrapcdn.com/twitter-bootstrap/2.1.0/css/bootstrap.no-icons.min.css">
	<link rel="stylesheet" href="//netdna.bootstrapcdn.com/font-awesome/2.0/css/font-awesome.css">
{% endblock %}

{% block body %}
	<div class="navbar navbar-fixed-top">
		<div class="navbar-inner">
			<a class="brand" href="#">Awesome!</a>
			{{ 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 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/twitter-bootstrap/2.1.0/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 %}
        {%- if item.level > 1 %}
            {%- set classes = classes|merge(['dropdown-submenu']) %}
        {%- else %}
            {%- set classes = classes|merge(['dropdown']) %}
        {%- endif %}
        {%- 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 matcher.isCurrent(item) 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 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) }}>{{ block('label') }}{% if item.level <= 1 %} <b class="caret"></b>{% endif %}</a>
{% endblock %}
 
{% block label %}{% if item.attribute('icon') is not empty %}
    		<i class="{{ item.attribute('icon') }}"></i> 
        {% endif %}{{ 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');
    	
		$menu->addChild('Projects', array('route' => 'acme_hello_projects'))
			->setAttribute('icon', 'icon-list');
			
		$menu->addChild('Employees', array('route' => 'acme_hello_employees'))
			->setAttribute('icon', 'icon-group');

        return $menu;
    }
    
    public function userMenu(FactoryInterface $factory, array $options)
    {
    	$menu = $factory->createItem('root');
    	$menu->setChildrenAttribute('class', 'nav pull-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', 'icon-user');
			
		$menu['User']->addChild('Edit profile', array('route' => 'acme_hello_profile'))
			->setAttribute('icon', 'icon-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() !== '/' && (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 fact, you don't need custom renderer at all. you can achieve this just in menu builder:

$sub = $menu->addChild('Sub', array(
    'uri' => '#',
    'linkAttributes' => array(
        'class' => 'dropdown-toggle',
        'data-toggle' => 'dropdown',
    ),
    'childrenAttributes' => array(
        'class' => 'dropdown-menu',
    ),
    'attributes' => array(
        'class' => 'dropdown',
    ),
));
foreach ($subMenuItems as $item) {
    $sub->addChild($item['name'], array(
        'route' => $item['route'],
    ));
}