This abuse of the twig templating engine can be used to generate menus given a fairly nice declaration syntax. Currently, it will generate a semi customized bootstrap menu

_area_subnav.html.twig

{% block subnav %}
  
    {# This is how you declare a menu #}

    {% include '::subnav.html.twig' with { pages: [
        { name: 'Manage', dropdown: [
            { route: 'customers', name: 'Customers' },
            { route: 'orders', name: 'Orders' },
            { route: 'chargebacks', name:'Chargebacks', role: 'ROLE_ADMIN' }
        ] },
        { route: 'settings', name: 'Settings' },
        { route: 'sales_report', name: 'Sales Report', role: 'ROLE_ADMIN' },
        { route: 'today_report', name: 'Today Report', params: { date: 'today' }, role: 'ROLE_ADMIN' }
    ] } %}
{% endblock %}

subnav.html.twig

<ul class="nav nav-pills {{ class|default }}">
    {% for route,name in pages|default([]) %}
        {% if name|keys|length > 0 %}
            {% set route = name.route|default %}
            {% set params = name.params|default({}) %}
            {% set role = name.role|default %}
            {% set class = name.class|default %}
            {% set anchor_class = name.anchor_class|default %}
            {% set dropdown = name.dropdown|default %}
            {% set name = name.name %}
        {% endif %}
        {% if dropdown|default %}
            {% set anchor_class = anchor_class|default ~ ' dropdown-toggle' %}
        {% endif %}
        {% if not role|default or is_granted(role) %}
            {% set class = (is_current_route(route) ? ' active' : '') %}
    <li class="{{ class }}">
        <a class="{{ anchor_class|default }}"
            {% if dropdown|default %}
                data-toggle="dropdown"
                href="#"
            {% else %}
                href="{{ path(route, params|default([])) }}"
            {% endif %}
                {# I'm so ashamed. Next to this is the end of the opening 'a' tag #}>

            {{ name }}
            {% if dropdown|default %}
                <i class="caret"></i>
            {% endif %}
        </a>
        {% if dropdown|default %}{% include '::subnav_dropdown.html.twig' with { dropdown: dropdown } %}{% endif %}
    </li>
        {% endif %}
    {% endfor %}
</ul>

subnav_dropdown.html.twig

<ul class="dropdown-menu">
    {% for route,name in dropdown|default([]) %}
        {% if name|keys|length > 0 %}
            {% set route = name.route %}
            {% set params = name.params|default({}) %}
            {% set role = name.role|default %}
            {% set class = name.class|default %}
            {% set anchor_class = name.anchor_class|default %}
            {% set name = name.name %}
        {% endif %}
        {% if not role|default() or is_granted(role) %}
            {% set class = (is_current_route(route) ? ' active' : '') %}
            <li class="{{ class }}"><a href="{{ path(route, params|default([])) }}" class="{{ anchor_class|default }}">{{ name }}</a></li>
        {% endif %}
    {% endfor %}
</ul>