How do I only display a list of users that have entries and hide the rest

Question

I want to list users that have created entries in a specific channel.

I tried it the Ben Parisak way, but that didn't work out.

here's the code that doesn't work (example 1):

{% set entryIds = craft.entries.section('agenda').datumBeginn('>= ' ~ todayMidnight).limit(null).ids() %}
{% set convivien = craft.users()
    .group('convivien')
    .status('active')
    .cf_convivien_hide('not 1')
    .relatedTo(entryIds)
    .orderBy('firstName')
    .all()
%}

If I had a user field within the agenda channel it would work. But I am trying to get the authors of those entries, and apparently they are not stored as a relation. Maybe this is intentional, maybe not.

Anyways: the workaround I found is really messy (example 2):

{% set entries = craft.entries.section('agenda').datumBeginn('>= ' ~ todayMidnight).limit(null).all() %}
{% set convivien = [] %}
{% for entry in entries %}
    {% set author = entry.author %}
    {% if author.groups[0].name == "Convivien" and not convivien|filter(item => item.id == author.id)|length %}{% set convivien = convivien|merge([{'name': author.name, 'id': author.id}]) %}{% endif %}
{% endfor %}
{% set convivien = convivien|sort %}

if code example 1 would work I could use the same code here:

<select name="convivien" id="veranstalter">
    <option value="">{{ "Kanton wählen"|t }}</option>
    {% for convivium in convivien %}
        <option value="{{ convivium.id }}"{% if convivienParam == convivium.id %} selected="selected"{% endif %}>{{ convivium.name }}</option>
    {% endfor %}
</select>

Does somebody know why example 1 is not working and how I could elegantly achieve this like I was Ben Parisak ;)

Answer 1

I would try it this way:

{% set authors = craft.entries.section('agenda').datumBeginn('>= ' ~ todayMidnight).select(['author']).all() %}

Authors should be a list of user ids.

Credit to an older post: Get array of titles instead of whole collection of entries' attributes

Answer 2

after some tinkering chatGPT came up with a rather elegant solution:

{# Today at midnight #}
{% set todayMidnight = now|date('Y-m-d 00:00:00') %}

{# All agenda entries from today #}
{% set entries = craft.entries.section('agenda').datumBeginn('>= ' ~ todayMidnight).limit(null).all() %}

{# Use map and arrow function to get the unique user IDs #}
{% set userIds = entries|map(entry => entry.author.id)|unique %}

{# Get the users based on the user IDs #}
{% set users = craft.users().group('convivien').status('active').cf_convivien_hide('not 1').id(userIds).orderBy('username').all() %}

{# Output the list of users #}
<ul>
  {% for user in users %}
    <li>{{ user.name }}</li>
  {% endfor %}
</ul>

I quite like this solution.