Field Validation in Admin when field are dependent on other fields - django-admin

Question

How can i apply validation in admin on various fields when they are dependent on each other ?
e.g. Let say in i have a Field A(BooleanField) and Field B (CharField) what i want to do is if in admin user select the Field A(checkbox) and does not enter anything in Field B
and if he tries to save ,it should throw an error like a normal blank=False gives. So how can i do this kind of validation in admin .
E.g Use Case
I have a table having the following structure :-
INTERVIEW_TYPES = (
('default', 'None'),
('Paired Visit','Paired Visit'),
('Time Series', 'Time Series'),
),
class Interview(models.Model):
ic_number = models.CharField(verbose_name ="Visit Configuration Number",max_length=20,unique=True,null =True,blank=True)
ic_description = models.TextField(verbose_name ="Visit Configuration Description",null = True,blank=True)
title = models.CharField(verbose_name ="Visit Configuration Title",max_length=80,unique=True)
starting_section = models.ForeignKey(Section)
interview_type = models.CharField(verbose_name = "Mapped Visit",choices=CHOICES.INTERVIEW_TYPES, max_length=80, default="Time Series")
select_rating = models.CharField(choices=CHOICES.QUESTION_RATING, max_length=80, default="Select Rating")
view_notes = models.CharField(choices=CHOICES.VIEW_NOTES, max_length=80, default="Display Notes")
revisit = models.BooleanField(default=False)
.....and so on ......
class Meta:
verbose_name = 'Visit Configuration'
verbose_name_plural = 'Visit Configurations'
# ordering = ('rpn_number',)
def __unicode__(self):
return self.title
Its admin.py
class InterviewAdmin(admin.ModelAdmin):
list_display = ('id','title', 'starting_section','ic_number','show_prior_responses')
raw_id_fields = ('starting_section',)
admin.site.register(Interview, InterviewAdmin)
In admin , If i select the checkbox of revisit and in the field interview_type(which will show a dropdown having choices None,Paired Visit , Time Series) if a User has selected None from that dropdown and then press save button it should throw me an error like a normal blank=False shows, saying "This field is required"
How can i do this kind validation where fields are dependent on each other ?
Please Ignore syntax error is any .
Thanks

Answer 1

I got confused in response_change and overriding clean method finally this is what i did
override clean method by making a model form in admin.py
class InterviewAdminForm(forms.ModelForm):
class Meta:
model = Interview
def clean(self, *args, **kwargs):
cleaned_data = super(InterviewAdminForm, self).clean(*args, **kwargs)
if self.cleaned_data['interview_type'] == "default" \
and self.cleaned_data['Revisit'] == True:
raise forms.ValidationError({'interview_type': ["error message",]})
return cleaned_data
class InterviewAdmin(admin.ModelAdmin):
# call the form for Validation
form = InterviewAdminForm
#....and so on ....