How do you make django form validation dynamic?

Question

I have a form that needs to have either a valid url or a valid file for uploading:

class ResourceUpload(ModelForm):
   ...        
   uploadedfile = forms.Fi         


        

Answer 1

my solution
pros: it keeps the asterisk for the really required field and default error messages

class Form(forms.ModelForm):
    field1 = SelectField
    field2 = ...
    field3 = ...

    def __init__(self, *args, **kwargs):
        super(Form, self).__init__(*args, **kwargs)
        if kwargs['data']:
            if kwargs['data'].get('field1') == '1':
                self.fields['field2'].required = True
                self.fields['field3'].required = False
            elif kwargs['data'].get('field1') == '2':
                self.fields['field2'].required = False
                self.fields['field3'].required = True