<nav id="tabs">
    <ul>
        {% for tabId, tab in tabs %}
            {% if tab %}
                {% set tabIsSelected = ((selectedTab is not defined and loop.first) or (selectedTab is defined and selectedTab == tabId)) -%}
                {% set class = tab.class ?? '' -%}
                <li>
                    <a id="tab-{{ tabId }}" class="tab{% if tabIsSelected %} sel{% endif %} {{ class }}" href="{{ tab.url }}" title="{{ tab.label }}">
                        {{ tab.label }}
                        {% if class == 'error' %}<span data-icon="alert"></span>{% endif %}
                    </a>
                </li>
            {% endif %}
        {% endfor %}
    </ul>
</nav>