Hide region when block menu is empty

Question

I got the 2nd level main menu in a block in the sidebar, drupal 8 correctly hides the menu (and the block) when the user browses a page that is not in this menu, but the theme continues to show the empty region. The condition {% if page.region %} is true. is there any way to solve this problem?

Answer 1

It is better to use construction

{% if page.region|render|striptags|trim|length > 0 %} ... {% endif %}

So you can check if there is some content or not.

Answer 2

I you use menu_block module, this patch will fix the problem of a region showing up even when there are no subitems for a menu. Only tested on menu block version 8.x-1.5.

Answer 3

You can use {% if page.region|render|striptags %} to make sure the regions actually has content. See also the discussion here: [meta] Themes improperly check renderable arrays when determining visibility.

Answer 4

I did it this way to reduce the number of renders.

{% set render_sidebar_first = page.sidebar_first|render %}
{% if render_sidebar_first and render_sidebar_first|striptags|trim|length > 0 %}
  {% block sidebar_first %}
    <aside class="{{ sidebar_class }}" role="complementary">
        {{ render_sidebar_first }}
    </aside>
  {% endblock %}
{% endif %}