Django form with multiple checkboxes - django

Question

I am really new to Django! I have a page that displays items with checkboxes next to them. The number of items/checkboxes varies. When a button is pressed, I want the corresponding checked item to be modified.
So far, I have tried to wrap it all in one form:
<form method="post">
{% csrf_token %}
{% for event in items %}
{{ event.eventID }}
<input type="checkbox" value="{{ event.eventID }}" name="choices">
{% endfor %}
<button type="submit">Approve</button>
</form>
I want to collect them in a Django form field. I am trying to use ModelMultipleChoiceField:
class ApproveEventForm(forms.Form):
choices = forms.ModelMultipleChoiceField(queryset = Event.objects.all(), widget=forms.CheckboxSelectMultiple())
And in my views, I want to edit the selected items:
def approve_event(request):
if request.method == "POST":
form = ApproveEventForm(request.POST)
print(form.errors)
if form.is_valid():
for item in form.cleaned_data['choices']:
item.approved = True
item.save()
else:
form = ApproveEventForm()
unapproved = Event.objects.filter(approved=False)
return render(request, 'app/approve_event.html', {'items': unapproved, 'form': form})
My form is not valid and form.errors prints: choices "" is not a valid value for a primary key.
How can I fix this? Or is there another way to access the selected items?
Edit: passed the form to the template.

Answer 1

Managed to fix it using MultipleChoiceField instead of ModelMultipleChoiceField. Then populated the choices with existing event IDs and passed it to the template.
In forms:
choices = forms.MultipleChoiceField(widget = forms.CheckboxSelectMultiple())
In views:
form.fields['choices'].choices = [(x.eventID, "Event ID: " + x.eventID) for x in unapproved]
Had to change some of the logic for finding and editing Event objects too.