如何在Django中删除字段并为ModelForm设置默认值？

Question

I have a ModelForm in my forms.py as follows:

class ChoiceForm(forms.ModelForm):
class Meta:
    model = Choice
    fields = ['choice_text', 'is_choice_correct']
    labels = {
        'choice_text': "",
        'is_choice_correct': ""
    }
    widgets = {
        "choice_text": forms.Textarea(),
        "is_choice_correct": "",
    }

Based on some conditions, I would like the is_correct_field , a boolean field to not display in the form and set default value for the field (because it is required) so that when I write form.save() in my views, there occurs no error.

However, I don't want to hide the form field. To make it more clear, here's what I want to say. I submit the form with only choice_text in my form. The form does not contain the field is_choice_correct , either hidden or displayed. When I save the form with form.save(), I want the is_choice_correct to be True.

Answer 1

Why not declare the default value for is_choice_correct on the model itself?

class Choice(models.Model):
    is_choice_correct = models.BooleanField(default=True)

Then exclude the field from the form as Exprator shows. If you want to include the field on the form only under some conditions, you can edit the form's .fields during __init__ .

class ChoiceForm(forms.ModelForm):

    def __init__(self,*args,**kwargs):
        super().__init__(*args,**kwargs) # important, call super() first or the form has no .fields attribute
        if my_condition:
            self.fields['is_choice_correct'] = Choice._meta.get_field('is_choice_correct').formfield()