How to set default selected value in django ModelForm ForeignKey

Question

I want to set select option preselected on my Model's ForeignKeyField in ModelForm. Below are my model and form. I want to only set preselected value=1 for State field in my ModelForm. So that it shown to the user as already selected option.

Customer Model:


class Customer(models.Model):
    """
    Customer model
    """

    GENDER_CHOICES = (('M', 'M'),
                     ('F', 'F'))
    SDW_CHOICES = (('S/o', 'S/o'),
                   ('D/o', 'D/o'),
                   ('W/o', 'W/o'))

    name = models.CharField(verbose_name='customer name', max_length=50,
                            help_text='max length 50 characters')
    guardian_name = models.CharField(verbose_name='customer guardian name', max_length=50,
                                     help_text='max length 50 characters')
    phone_no_1 = models.CharField(verbose_name='customer phone number 1', max_length=10, null=True, blank=True,
                                  help_text='max length 10 digits')
    phone_no_2 = models.CharField(verbose_name='customer phone number 2', max_length=10, null=True, blank=True,
                                  help_text='max length 10 digits')
    address = models.CharField(verbose_name='customer address', max_length=150,
                               help_text='max length 150 characters')
    state = models.ForeignKey(State, help_text='Please select from list')
    district = models.ForeignKey(District, help_text='Please select from list')
    village_or_city = models.ForeignKey(VillageOrCity, help_text='Please select from list')
    created_on = models.DateTimeField(verbose_name='customer added on', auto_now_add=True)
    updated_on = models.DateTimeField(verbose_name='customer last modified', auto_now=True)
    remark = models.TextField(max_length=150, null=True, blank=True, help_text='max length 150 characters')
    gender = models.CharField(max_length=1, choices=GENDER_CHOICES, help_text='Please select from list')
    image = models.ImageField(upload_to=MEDIA_ROOT, default=DEFAULT_USER_IMAGE)
    sdw = models.CharField(verbose_name='Son/daughter/wife of', max_length=3, choices=SDW_CHOICES,
                           help_text='Please select from list')
    caste = models.ForeignKey(Caste, help_text='Please select from list')
    created_by = models.ForeignKey(User, related_name='created_by', null=True)
    updated_by = models.ForeignKey(User, related_name='updated_by', null=True)


CreateCustomerForm:

class CreateCustomerForm(forms.ModelForm):
"""
CreateCustomerForm class. Renders Customer model form
"""

class Meta:

    model = Customer
    fields = ('name', 'sdw', 'guardian_name', 'phone_no_1',
              'phone_no_2', 'address', 'state', 'district',
              'village_or_city', 'remark', 'gender', 'caste',
              'image'
              )
    widgets = {
                'name': forms.TextInput(attrs={'placeholder': 'Enter customer name',
                                               'required': 'required',
                                               'autofocus': 'autofocus', 'size': "50"
                                               }
                                        ),
                'sdw': forms.Select(attrs={'required': 'required',
                                           }
                                    ),
                'guardian_name': forms.TextInput(attrs={'placeholder': 'Enter guardian name',
                                                        'required': 'required', 'size': "50"
                                                        }
                                                 ),
                'phone_no_1': forms.TextInput(attrs={'placeholder': 'Enter phone number',
                                                     'size': "50"
                                                     }
                                              ),
                'phone_no_2': forms.TextInput(attrs={'placeholder': 'Enter phone number',
                                                     'size': "50"
                                                     }
                                              ),
                'address': forms.TextInput(attrs={'placeholder': 'Enter address',
                                                  'required': 'required', 'size': "50"
                                                  }
                                                 ),
                'state': forms.Select(attrs={'required': 'required',
                                             }
                                      ),
                'district': forms.Select(attrs={'required': 'required',
                                                }
                                         ),
                'village_or_city': forms.Select(attrs={'required': 'required',
                                                       }
                                                ),
                'remark': forms.Textarea(attrs={'placeholder': 'Enter remark',
                                                 }
                                          ),
                'gender': forms.Select(attrs={'required': 'required',
                                              }
                                       ),
                'caste': forms.Select(attrs={'required': 'required',
                                             }
                                      ),
                }

Answer 1

Set initial data in Django's CBV using initial.

class CreateCustomerView(LoginRequiredMixin, CreateView):
    """
    Handles request for '/add/customer/'
    """

    initial = {'state': '1'
               }
    form_class = CreateCustomerForm
    template_name = CREATE_CUSTOMER_TEMPLATE

It will render the template with pre-populated data.

Answer 2

When loading the form, you can set the initial value for ChoiceFields, so this should work

default_state = State.objects.get(id=1)
form = CreateCustomerForm(initial={'state': default_state})

Take a look at Setting the selected value on a Django forms.ChoiceField for alternative approaches to setting a default value