CODEWITHSUNDEEP
djangodjango-forms
Krystian Cybulski
Krystian Cybulski

Reputation: 11118

Django form with choice field not providing None as a choice

I have a choice field in a form defined as

REFERRAL_CHOICES = (
    (None, 'Please choose'),
    ('search', 'From a search engine'),
    ('social', 'From a social network'),
)
referral_source = forms.ChoiceField(
    choices=REFERRAL_CHOICES
)

I also have a clean_company_size function which checks if the field is set to a good value:

def clean_company_size(self):
    company_size = self.cleaned_data.get('company_size', None)
    if company_size is None:
        raise ValidationError('Please select a company size')

    return company_size

If I add a or company_size == 'None' condition to the above None check, all works well. However, I am curious why the None value is being cast to a string. What is the best way of accomplishing a default prompts in a choice field and having that field be required?

Upvotes: 1

Views: 1853

Answers (1)

furins
furins

Reputation: 5048

All POST and GET variables, as well as Select HTML tag values are initially sent as strings. Django converts them to -say- int when it is deductable from the model. In your case it is not possible to distinguish a "None" string from a "None" object, they are both possible values. You may prefer using "" instead of None in your REFERRAL_CHOICHES

Upvotes: 1

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