How to get a list of unique related entries from within a related entries loop

Question

Bear with me as I am not sure the best way to explain this. But to try and summarise... how can I loop through related entries (locations) inside a a related entries loop (exams -> related to the current entry/page) but ONLY output the locations and ONLY output the unique locations (ie. I don't want it t show location1, location1, location2, location1. I just want it to show location1 and location2 (once - unique). This is where I am at, but not working yet.

Here is a screenshot to try and illstrate:

I only want Bushy to appear once, not 4 times.

So my page is setup like this; First I set the Mock Exams to find all the Mock Exams related to the current entry (page). Like so:

{% set mockExams = craft.entries
  .section('mockExams')
  .with('location')
  .relatedTo({
  targetElement: entry,
  field: 'mockExamCategory'
})
  .all() %}

I am then using this code to list all the mock exams in 2 separate areas on the page. This works fine and as expected.

However, I need to then get all the unique location entries that are related to the mock exams. I took me ages to fathom this out on how to to do this. I only managed with some great support through the Discord channel.

Anyway, the way this was finally achieved was as follows:

  {% set uniqueLocations = [] %}
  {% set uniqueLocationsIds = [] %}
  {% for entry in mockExams %}
    {% set locations = craft.entries.section('locations').relatedTo(entry.id).all() %}

    {% for location in locations %}
      {% if location.id not in uniqueLocationsIds %}
        {% set uniqueLocationsIds = uniqueLocationsIds|merge([location.id]) %}
        {% set uniqueLocations = uniqueLocations|merge([location]) %}
      {% endif %}
    {% endfor %}
  {% endfor %}

{% for location in uniqueLocations %}
  {{ location.title }}<br />
  {{ location.address }}
{% endfor %}

I have written this up for reference if anyone else comes across this.

But also for anyone more experienced in Craft - is this the most efficient way or is there a more efficient/streamlined approach?

Answer 1

How about this?

{% set uniqueLocations = craft.entries.section('locations').relatedTo(mockExams).all() %}

{% for location in uniqueLocations %}
  {{ location.title }}<br />
  {{ location.address }}
{% endfor %}