Symfony: display all flash messages in a twig template

base.html.twig

{% if app.session.flashbag.peekAll|length > 0 %}
            {% for type, messages in app.session.flashbag.all %}
                {% for message in messages %}
                    <div class="{{ type ? type : '' }}">
                        {{ message|trans({}, domain|default('messages')) }}
                    </div>
                {% endfor %}
            {% endfor %}
        {% endif %}