wtforms: InputRequired doesn't accept 0 as valid

Hello,

I have a form that looks like this,

class VoteForm(Form):
    article_id = IntegerField('article_id', [validators.DataRequired()])
    vote_type  = IntegerField('vote_type', [validators.InputRequired(), validators.NumberRange(min = 0, max = 1)])

and create the form with,

form = VoteForm(data = request.json_body)

request.json_body is the dictionary {u'article_id': 1, u'vote_type': 0}.

I would expect that the value 0 is fine with InputRequired but it seems it is not.

About this issue

Original URL
State: closed
Created 10 years ago
Reactions: 1
Comments: 15 (1 by maintainers)

Commits related to this issue

Smarter missing input validation. Resolves #100 — committed to Guzzardo/wtforms by Guzzardo 10 years ago

Most upvoted comments

I believe this issue should be reopened. It is not at all intuitive that InputRequired validator should fail on BooleanField when the value is False, since InputRequired specifically tests for whether a value is specified rather than truthiness. This is especially annoying when building APIs.

Yes, there is a workaround. Nevertheless, InputRequired is broken according to its own spec. At the very least the documentation should reflect this fact. However, the change should just be merged into mainline.

To address backwards compatibility, just bump the major version to indicate a breaking change.

+17

boompig on Jul 6, 2017

Why this issue was closed and how to handle it? I have

class MyForm(wtforms.Form):
    hour = wtforms.IntegerField(validators=[validators.InputRequired(), validators.NumberRange(0, 23)])

and when I pass 0 as hour validation fails… Input is present so I don’t expect InputRequired() to complain.

warvariuc on Jul 22, 2015

why close this issue? the problem is still exist, i have to change the field‘s attribute to OPtional() to avoid the error …

ghost on Jan 18, 2017

Hi @wilbertom, I’ve read your diff, but what bothers me, why it’s not in the core. Is this solution bad?

warvariuc on Jul 22, 2015

My workaround is to replace the InputRequired validator with a AnyOf([True, False]).

Guzzardo on Sep 30, 2014

Also, neither InputRequired nor DataRequired accept False as a valid input for a BooleanField.

    def test_required_bool(self):
        class TestForm(wtforms.Form):
            required_bool = wtforms.BooleanField(validators=[wtforms.validators.InputRequired()])

        form = TestForm()
        self.assertFalse(form.validate(), form.errors)
        self.assertTrue('required_bool' in form.errors)

        form.process(required_bool=False)
        self.assertEqual(form.required_bool.data, False)
        self.assertTrue(form.validate(), form.errors) # Fails with form.errors containing {'required_bool': [u'This field is required.']}

This means that when a BooleanField is required, it is required to be True!

Guzzardo on Sep 30, 2014