ModelForm field included even when not in fields - django

Question

I have the following model:
class Test(models.Model):
name = models.CharField(max_length=100)
And the admin:
class TestForm(forms.ModelForm):
confirm_name = forms.CharField(max_length=100)
...
#admin.register(Test)
class TestAdmin(admin.ModelAdmin):
form = TestForm
fields = ('name',)
create_fields = ('name', 'confirm_name')
def get_fields(self, request, obj=None):
fields = super().get_fields(request, obj)
if not obj:
fields = self.create_fields
return fields
Everything works fine. But when you add a record and then try to edit it, I get the error "Please correct the error below." without showing any field errors. I checked the form errors and it says confirm_name should not be empty. Why is it still being included if it's not added in fields?

Answer 1

You need to use add_form instead of get_fields.
In your example
class CreateTestForm(forms.ModelForm):
name = models.CharField(max_length=100)
confirm_name = models.CharField(max_length=100)
#.... your validation logic
class UpdateTestForm(forms.ModelForm):
name = models.CharField(max_length=100)
and in your admin.py
#admin.register(Test)
class TestAdmin(admin.ModelAdmin):
form = TestForm
add_form = CreateTest
def get_form(self, request, obj=None, **kwargs):
"""
Use special form during test creation
"""
defaults = {}
if obj is None:
defaults['form'] = self.add_form
defaults.update(kwargs)
return super().get_form(request, obj, **defaults)
Credits from django.contrib.auth.admin

Answer 2

Field for admin form are from TestForm
class TestForm(forms.ModelForm):
confirm_name = forms.CharField(max_length=100)
You can use:
class CreateTestForm(forms.ModelForm):
confirm_name = forms.CharField(max_length=100)
class Meta:
model = Model
field = ('name', 'confirm_name')
class UpdateTestForm(forms.ModelForm):
class Meta:
model = Model
field = ('name',)
#admin.register(Test)
class TestAdmin(admin.ModelAdmin):
def get_form(self, request, obj=None, change=False, **kwargs):
if obj:
kwargs['form'] = UpdateTestForm
else:
kwargs['form'] = CreateTestForm
return super().get_form(request, obj, change, **kwargs)