Django - How to make a form for a model's foreign keys?

Question

Here\'s what I\'m trying to do. I\'m wondering if someone can suggest a good approach:

models.py:

class Color(models.Model):
    name = models.CharField         


        

Answer 1

I don't think you want to use a ModelForm here. It will never be valid without some hackery, since you won't have found or created the dog object before calling is_valid().

Instead, I'd just use a regular form, and then override the save method of DogRequest to find or create the dog.

Update: Responding to the followup question in the comment, I haven't tested this, but something like it should work.

class DogRequestForm(forms.Form):
    id = forms.IntegerField(required=False, widget=forms.HiddenInput())
    color = forms.ModelChoiceField(queryset=Color.objects.all())
    speed = forms.ModelChoiceField(queryset=Speed.objects.all())

and then when you create an instance of this form for your edit view you need to instantiate it with something like this:

data = {
    'id': dog_request_id,
    'color': dog_color,
    'speed': dog_speed,
}
form = DogRequestForm(data)

where you populate the current dog_request_id, dog_color and dog_speed from your existing DogRequest object.