CODEWITHSUNDEEP
pythondjangodjango-forms
Belmin Fernandez
Belmin Fernandez

Reputation: 8647

Django: How to check if the user left all fields blank (or to initial values)?

I know is_valid() on a bounded form checks if all required data is entered. This is not what I want. I want to check if any field was filled on the form.

Any ideas?

Elaborating:

I want to give the user the choice of not filling in the form at all. However, if they attempt to fill it in (ie: changed a value in a field from it's initial value---usually empty value), I want to validate it.

The view would be something like this:

def get_opinion(request):

    if request.method == 'POST':
        f = OpinionForm(request.POST)
        if form_is_blank(f):
            return HttpResponseRedirect(reverse('thank_you_anyway'))
        elif f.is_valid():
            #Process here
            return HttpResponseRedirect(reverse('thanks_for_participating'))
    else:
        initial = {'weekday': date.today().strftime('%A')}
        f = OpinionForm(initial=initial)

    return render_to_response(
        'get_opinion.html',
        {'form': f,},
        RequestContext(request)
    )

What I want is the form_is_blank() part.

Upvotes: 20

Views: 14570

Answers (5)

atufa shireen
atufa shireen

Reputation: 407

Use modelformset_Factory and pass your custom formset to it

Upvotes: 0

Belmin Fernandez
Belmin Fernandez

Reputation: 8647

Guess I have to answer my own question.

Apparently, there's an undocumented Form function: has_changed()

>>> f = MyForm({})
>>> f.has_changed()
False
>>> f = MyForm({'name': 'test'})
>>> f.has_changed()
True
>>> f = MyForm({'name': 'test'}, initial={'name': 'test'})
>>> f.has_changed()
False

So this would do nicely as the replacement for form_is_blank() (reverted of course).

Upvotes: 30

Mikhail Korobov
Mikhail Korobov

Reputation: 22248

You should set required=False for all fields in the form and override the clean method to do custom validation. See the current documentation for more.

Upvotes: 3

Jan Matejka
Jan Matejka

Reputation: 1970

To get this functionality work for subset of Forms used in the actual <form> tag you also need to define

class YourForm(forms.ModelForm):
    def full_clean(self):
        if not self.has_changed():
            self._errors = ErrorDict()
            return

        return super(YourForm, self).full_clean()

so when the user is prompted to fix validation errors it doesnt display errors from the forms which you want to validate only if some value isn't blank (or default).

Upvotes: 4

mouad
mouad

Reputation: 70059

If you have put required=True in your forms field or in the model blank=False so is_valid() should return False.

Upvotes: 1

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