Accessing additional fields from a grouper in a Django group_by - django

Question

How can I access fields other than the grouper in a Django group_by function?
class dateEvent(models.Model):
event = models.ForeignKey('Event', on_delete=models.CASCADE)
start_date_time = models.DateTimeField(auto_now=False, auto_now_add=False)
def __str__(self):
return "%s" % (self.event.title)
def description(self):
return "%s" % (self.event.description)
class Event(models.Model):
description = RichTextUploadingField(max_length=200)
view:
def my_view(request):
events = dateEvent.objects.all()
context = {
'events': events,
}
return render(request, 'view.html', context)
template:
<ul>
{% for event in dateEvents_list %}
<li><h5>Event: {{ event.grouper }}</h5>
<h6>Description: {{ event.description }}</h6> #How can access the description of the main event?
<ul>
{% for dateEvent in event.list %}
<li>date: {{ dateEvent.start_date_time }}</li>
{% endfor %}
</ul>
</li>
{% endfor %}
</ul>
I'd like to have the title, which is the grouper so it's fine, but also the description.

Answer 1

You can also access your grouper's list objects to get details about the "first record" in your group. So using:
event.grouper.list.0.<any_model_field_you_want>
Will work just fine. I have this in production and it solved my needs immediatly. I found this in a rejected feature request for Django here: https://code.djangoproject.com/ticket/13452
If you need to traverse your model's relationship tree you can do the following.
event.grouper.list.0.<related_model_name>.<any_model_field_you_want>

Answer 2

You can access model attributes from the grouper directly using event.grouper.<any-model-attribute>.
In your example here is how it would look:
<ul>
{% for event in dateEvents_list %}
<li><h5>Event: {{ event.grouper }}</h5>
<h6>Description: {{ event.grouper.description }}</h6>
<ul>
{% for dateEvent in event.list %}
<li>date: {{ dateEvent.start_date_time }}</li>
{% endfor %}
</ul>
</li>
{% endfor %}
</ul>
I can't find any documentation around this usage.