How would I use django.forms to prepopulate a choice field with rows from a model?

问题

I have a ChoiceField in my form class, presumably a list of users. How do I prepopulate this with a list of users from my User model?

What I have now is:

class MatchForm(forms.Form):

  choices = []

  user1_auto = forms.CharField()
  user1 = forms.ChoiceField(choices=choices)
  user2_auto = forms.CharField()
  user2 = forms.ChoiceField(choices=choices)

  def __init__(self):
      user_choices = User.objects.all()
      for choice in user_choices:
          self.choices.append(
              (choice.id, choice.get_full_name())
          )

This doesn't seem to work (otherwise I wouldn't be here). Thoughts?

To clarify, when I attempt to render this form in a template, it simply outputs nothing, unless I remove the ChoiceFields and __init__() method.

Also, what if I only want a list of the users' full names in my field? That is, I'd like to control the display output of each user object (so ModelChoiceField isn't really an option).

回答1:

It looks like you may be looking for ModelChoiceField.

user2 = forms.ModelChoiceField(queryset=User.objects.all())

This won't show fullnames, though, it'll just call __unicode__ on each object to get the displayed value.

Where you don't just want to display __unicode__, I do something like this:

class MatchForm(forms.Form):
    user1 = forms.ChoiceField(choices = [])

    def __init__(self, *args, **kwargs):
        super(MatchForm, self).__init__(*args, **kwargs)
        self.fields['user1'].choices = [(x.pk, x.get_full_name()) for x in User.objects.all()]

回答2:

class MatchForm(forms.Form):
  choices = tuple(User.objects.all().values_list())

  user1_auto = forms.CharField()
  user1 = forms.ChoiceField(choices=choices)
  user2_auto = forms.CharField()
  user2 = forms.ChoiceField(choices=choices)

This should work.

来源：https://stackoverflow.com/questions/4593292/how-would-i-use-django-forms-to-prepopulate-a-choice-field-with-rows-from-a-mode