Question

Being a Django newbie, I have a question to ask, which should be very simple, but I just can’t figure it out:

I have created a model like the one below:

from django.db import models
from django.core.exceptions import ValidationError

def validate_case_id(value):
    if value != "testing":
        raise ValidationError("type testing")

class case_form3_tb(models.Model):
    case_id = models.CharField(max_length=20, blank=True, null=True, verbose_name="Case ID", validators=[validate_case_id])
    wound_others = models.BooleanField(verbose_name="Others")
    wound_others_desc = models.CharField(max_length=200, blank=True, null=True, verbose_name="Others (Description)")    

I want to validate it in a way that if wound_others is ticked, then wound_others_desc must not be blank.

I just learn how to validate one single text field, but what if the text field is validated based on some other fields?

Thanks.

Answer 1

You should validate at the model level, i.e., write a clean() method for the model:

def clean(self):
    from django.core.exceptions import ValidationError
    if self.wound_others and not self.wound_others_desc:
        raise ValidationError('Description must not be blank.')

As a side note, the model name you chose is heavily anti-pythonic. You should always follow the CapWords convention for Python class names.