#35126: forms.NullBooleanField's validation logic is surprising
------------------------------+--------------------------------------
Reporter: Jeremy Lainé | Owner: nobody
Type: Bug | Status: new
Component: Forms | Version: 5.0
Severity: Normal | Resolution:
Keywords: | Triage Stage: Unreviewed
Has patch: 0 | Needs documentation: 0
Needs tests: 0 | Patch needs improvement: 0
Easy pickings: 0 | UI/UX: 0
------------------------------+--------------------------------------
Description changed by Jeremy Lainé:
Old description:
> Reading NullBooleanField's code lead me to believe that it would clean
> `"1"` to `True`, and `"0"` to `False`", just like `BooleanField` does:
>
> https://github.com/django/django/blob/10c7c7320baf1c655fcb91202169d77725c9c4bd/django/forms/fields.py#L850
>
> A simple field-level test works:
>
> {{{
> >>> from django import forms
> >>> field = forms.NullBooleanField()
> >>> field.clean("1")
> True
> >>> field.clean("0")
> False
> }}}
>
> But using this in an actual form fails, not the difference between the
> `BooleanField` and `NullBooleanField`:
>
> {{{
> >>> class DemoForm(forms.Form):
> ... field_a = forms.BooleanField()
> ... field_b = forms.NullBooleanField()
> ...
> >>> form = DemoForm({"field_a": "1", "field_b": "1"})
> >>> form.is_valid()
> >>> form.cleaned_data
> {'field_a': True, 'field_b': None}
> }}}
>
> The problem is that by default `NullBooleanField` uses a
> `NullBooleanSelect` which mangles the submitted data for some obscure
> backwards-compatibility reason:
>
> https://github.com/django/django/blob/10c7c7320baf1c655fcb91202169d77725c9c4bd/django/forms/widgets.py#L816
New description:
Reading NullBooleanField's code lead me to believe that it would clean
`"1"` to `True`, and `"0"` to `False`", just like `BooleanField` does:
https://github.com/django/django/blob/10c7c7320baf1c655fcb91202169d77725c9c4bd/django/forms/fields.py#L850
A simple field-level test works:
{{{
>>> from django import forms
>>> field = forms.NullBooleanField()
>>> field.clean("1")
True
>>> field.clean("0")
False
}}}
But using this in an actual form fails, note the difference between the
`BooleanField` and `NullBooleanField`:
{{{
>>> class DemoForm(forms.Form):
... field_a = forms.BooleanField()
... field_b = forms.NullBooleanField()
...
>>> form = DemoForm({"field_a": "1", "field_b": "1"})
>>> form.is_valid()
>>> form.cleaned_data
{'field_a': True, 'field_b': None}
}}}
The problem is that by default `NullBooleanField` uses a
`NullBooleanSelect` which mangles the submitted data for some obscure
backwards-compatibility reason:
https://github.com/django/django/blob/10c7c7320baf1c655fcb91202169d77725c9c4bd/django/forms/widgets.py#L816
--
--
Ticket URL: <https://code.djangoproject.com/ticket/35126#comment:1>
Django <https://code.djangoproject.com/>
The Web framework for perfectionists with deadlines.
--
You received this message because you are subscribed to the Google Groups
"Django updates" group.
To unsubscribe from this group and stop receiving emails from it, send an email
to django-updates+unsubscr...@googlegroups.com.
To view this discussion on the web visit
https://groups.google.com/d/msgid/django-updates/0107018d1d15e166-290ce659-0153-44d4-b39c-82467f3dd1d1-000000%40eu-central-1.amazonses.com.
