Django ModelForms: cleanest way to hide fields and enforce defaults - django

Question

Let's say I have a single ModelForm which can be filled out by different tiers of users. The Admin can edit any field of that form; but for other users, I need to have certain fields pre-defined, and read-only and/or hidden.
Using my CBV's get_form_kwargs method, I have made the form aware of the user that's bringing it up, and, in its __init__ method I react accordingly, tweaking the form's exclude, and the fields' required and initial properties; and then, in my view's form_valid, I further enforce the values. But, frankly, I'm neither sure that every operation I do is actually needed, nor whether there's some gaping hole I'm not aware of.
So, what's the best, cleanest way of doing this?

Answer 1

Assuming there aren't a lot of combinations, I would create a different form that meets the different needs of your users. Then override def get_form_class and return the correct form based on your needs. This keeps the different use cases separate and gives flexibility if you need to change things in the future without breaking the other forms.
# models.py
class Foo(models.Model):
bar = model.CharField(max_length=100)
baz = model.CharField(max_length=100)
biz = model.CharField(max_length=100)
# forms.py
class FooForm(forms.ModelForm): # for admins
class Meta:
model = Foo
class FooForm(forms.ModelForm): # users who can't see bar
boo = forms.CharField()
class Meta:
model = Foo
exclude = ['bar']
class FooFormN(forms.ModelForm): # as many different scenarios as you need
def __init__(self, *args, **kwargs)
super(FooFormN, self).__init__(*args, **kwargs)
self.fields['biz'].widget.attrs['readonly'] = True
class Meta:
model = Foo
# views.py
class SomeView(UpdateView):
def get_form_class(self):
if self.request.user.groups.filter(name="some_group").exists():
return FooForm
# etc.