Django ModelForm instance with custom queryset for a specific field

Question

I have a model not unlike the following:

class Bike(models.Model):
    made_at = models.ForeignKey(Factory)
    added_on = models.DateField(auto_add_now=True)

All users may work at a number of factories and therefore their user profiles all have a ManyToManyField to Factory.

Now I want to construct a ModelForm for Bike but I want the made_at list to consist of only factories at which the current user works. The idea is that users should be able to add bikes that they've assembled and enter which of the factories the bike was made at.

How do I do that?

Answer 1

You question might be a dupe of this.

S. Lott's answer there is the ticket to solve your problem. He answered:

ForeignKey is represented by django.forms.ModelChoiceField, which is a ChoiceField whose choices are a model QuerySet. See the reference for ModelChoiceField.

So, provide a QuerySet to the field's queryset attribute. Depends on how your form is built. If you build an explicit form, you'll have fields named directly.

form.rate.queryset = Rate.objects.filter(company_id=the_company.id) If you take the default ModelForm object, form.fields["rate"].queryset = ...

This is done explicitly in the view. No hacking around.

Answer 2

try something like this in the view

form  = BikeForm()
form.fields["made_at"].queryset = Factory.objects.filter(user__factory)

modify the Factory queryset so that it identifies the factory which the user works at.

Answer 3

Nowaday, you should use:

    form.base_fields['alumno_item'].queryset = AlumnoItem.objects.prefetch_related(
        'alumno',
        'alumno__estudiante',
        'alumno__estudiante__profile',
        'item'
    )