How do I set user field in form to the currently logged in user?

Question

I'm making an election information app, and I want to allow the currently logged-in user to be able to declare himself and only himself as a candidate in an election.

I'm using Django's built-in ModelForm and CreateView. My problem is that the Run for Office form (in other words, the 'create candidate' form) allows the user to select any user in the database to make a candidate.

I want the user field in the Run for Office to be automatically set to the currently logged-in user, and for this value to be hidden, so the logged-in user cannot change the value of the field to someone else.

views.py

class CandidateCreateView(CreateView):
    model = Candidate
    form_class = CandidateForm
    template_name = 'candidate_create.html'

    def form_valid(self, form):
        f = form.save(commit=False)
        f.save()
        return super(CandidateCreateView, self).form_valid(form)

forms.py

class CandidateForm(forms.ModelForm):
    class Meta:
        model = Candidate

models.py

class Candidate(models.Model):
    user = models.ForeignKey(UserProfile)
    office = models.ForeignKey(Office)
    election = models.ForeignKey(Election)
    description = models.TextField()

    def __unicode__(self):
        return unicode(self.user)

    def get_absolute_url(self):
        return reverse('candidate_detail', kwargs={'pk': str(self.id)})

Answer 1

1. Remove user field from rendered form (using exclude or fields, https://docs.djangoproject.com/en/dev/topics/forms/modelforms/#selecting-the-fields-to-use )

   class CandidateForm(forms.ModelForm):
       class Meta:
           model = Candidate
           exclude = ["user"]
   

2. Find user profile and set user field in the create view.

   class CandidateCreateView(CreateView):
       ...
       def form_valid(self, form):
           candidate = form.save(commit=False)
           candidate.user = UserProfile.objects.get(user=self.request.user)  # use your own profile here
           candidate.save()
           return HttpResponseRedirect(self.get_success_url())