How to save parent objects within the form_valid - django

Question

I have a class based view. I am trying to save an object with it's association. I have the following error :
NOT NULL constraint failed: boxes_suggestion.box_id
More explanation: I have a SuggestionBox (Model) and each Participant could add Comments into it. it's sort of a doodle clone.
detail.html
<h3>{{box.title}}</h3>
<form action="." method="post">{% csrf_token %}
{{ form.as_p }}
<input id="box_id_value" type="hidden" name="box_id_value" value='{{box.id}}' />
<input type="submit" class="btn btn-info" value="Add suggies 1" />
</form>
views.py
class SuggiesForm(FormView):
'''
Display the form
Otherwise
Process the form
1-Get the suggestion_box_id
2-Save the comment associated with that suggestion box.
'''
template_name = 'boxes/detail.html'
form_class = SuggestionForm
success_url = '/boxes/success'
box_instance = ''
def get_context_data(self, **kwargs):
'''
Retrieve the id of the Suggestion Box
'''
context = super(SuggiesForm, self).get_context_data(**kwargs)
#Find The appropriate Box so that user can add Suggies
context['box'] = Box.objects.get(pk=self.kwargs['pk'])
box_instance = context['box']
return context
def form_valid(self, form):
'''
'''
form.save(commit=False)
#box = box_instance
form.box = Box.objects.first()
form.participant = Suggestion.objects.first()
form.save()
return super(SuggiesForm, self).form_valid(form)
models.py
#python_2_unicode_compatible
class Box(models.Model):
"""
Box model
"""
def __str__(self):
return self.title
id = models.UUIDField(primary_key=True, default=uuid.uuid4, editable=False)
title = models.CharField(max_length=40, blank=True, null=True)
identify = models.BooleanField(default=False)
activate = models.BooleanField(default=False)
created_at = models.DateField(auto_now_add=True)
updated_at = models.DateField(auto_now=True)
#expiration_date = models.DateField(auto=Date in Future, blank=True, null=False)
#slug = AutoSlugField(_('slug'), populate_from="id")
#url(slug)
#python_2_unicode_compatible
class Participant(models.Model):
"""
Participant Model
"""
def __str__(self):
return self.email
id = models.UUIDField(primary_key=True, default=uuid.uuid4, editable=False)
email = models.EmailField(blank=True, null=True, default='anonymous#email.com')
username = models.CharField(max_length=40, blank=True, null=True)
box = models.ForeignKey(Box, on_delete=models.CASCADE)
created_at = models.DateField(auto_now_add=True)
updated_at = models.DateField(auto_now=True)
#python_2_unicode_compatible
class Suggestion(models.Model):
"""
For adding comments (or suggestions)
"""
def __str__(self):
return self.comment[0:10]
id = models.UUIDField(primary_key=True, default=uuid.uuid4, editable=False)
comment = models.CharField("",max_length=250, blank=True, null=True)
box = models.ForeignKey(Participant, on_delete=models.CASCADE)
created_at = models.DateField(auto_now_add=True)
updated_at = models.DateField(auto_now=True)

Answer 1

You correctly used commit=False, but then added the attributes onto the form object itself instead of the object returned from the save. It should be:
object = form.save(commit=False)
object.box = Box.objects.first()
object.participant = Suggestion.objects.first()
object.save()