Showing/Hiding children of a Structure based on categories

Question

I'm a newbie, so please excuse this if its a super simple question. I have a structure set up like so:

• Parent Section 1
  - Child 1A (category: pro-users)
  - Child 1B (category: pro-users)
  - Child 1c

• Parent Section 2
  - Child 2A 
  - Child 2B

I am wanting to output a navigation/landing page with the children viewable or not based on what category they are set to. So for example, on a specific page, I just want items with category "pro-users" (two entries specified above) to show up, with their parent title, and not any of the others. I also don't want the parent titles of sections that don't contain matching elements (Parent Section 2) to show. So, in this example where I just want the children with category "power-users" to show up, it would only show me:

PARENT SECTION 1
   Child 1A
   Child 1B

And nothing else. Please ask for more specifics if this doesn't make sense. I just can't figure out how to a) only show the children that are matching the categories I specify (in this case "pro-users") and to also not show the subsequent parent title if there are no matching children (as is the case for Parent Section 2).

Thanks in advance for your help, I really really appreciate it!

Answer 1

Something like this should do the trick! You want to get all the section parent entries, then search for child entries that are related to the category you want.

{% set parents = craft.entries.section('your_structure_handle').level(1) %}

{% for parent in parents %}
    {% set children = craft.entries.decendantOf(parent).relatedTo(category) %}
    {% if children|length %}
        <h1>{{parent.title}}</h1>
        <ul>
        {% for child in children %}
            <li>{{child.title}}</li>
        {% endfor %}
        </ul>
    {% endif %}
{% endfor %}