Re: [Django] #22282: models.BooleanField.blank should be 'False' if BooleanField has choices

[Django]

#22282: models.BooleanField.blank should be 'False' if BooleanField has choices
-+-
 Reporter:  django@… |Owner:  nobody
 Type:  Uncategorized|   Status:  closed
Component:  Database layer   |  Version:  1.6
  (models, ORM)  |   Resolution:  needsinfo
 Severity:  Normal   | Triage Stage:
 Keywords:   |  Unreviewed
Has patch:  0|  Needs documentation:  0
  Needs tests:  0|  Patch needs improvement:  0
Easy pickings:  1|UI/UX:  0
-+-
Changes (by aaugustin):

 * status:  new => closed
 * needs_better_patch:   => 0
 * resolution:   => needsinfo
 * needs_tests:   => 0
 * needs_docs:   => 0


Comment:

 Let's start with form fields. A `BooleanField` is rendered by default as a
 checkbox. If it's mandatory (e.g. accept terms & conditions), you set
 `blank = False`. If it's optional, you set `blank = True`.

 Let's now look at model fields. Only the second case makes sense. That's
 why Django forces `blank = True`. You're right, Django could warn that
 `blank = False` is a misconfiguration that probably doesn't do what you
 expect.

 If I understand correctly, you'd like to use a different widget, maybe a
 radio list with two choices. If a value that doesn't match either of your
 choices is returned, as far as I can tell, `BooleanField.to_python` is
 going to raise a `ValidationError`.

 I don't understand why you're saying that "There's no way to make sure the
 value is not blank." On the contrary, Django enforces that you always get
 `True`, `False` or an exception at the model layer. As explained above,
 always getting `True` or an execption isn't interesting at the model
 layer.

 I'm not sure where "`BooleanField` assumes a `None` value to be `False`"
 comes from either.

 Could you show why your example doesn't work? Either an exception
 traceback or a failing test case will do. Thank you!

-- 
Ticket URL: 
Django 
The Web framework for perfectionists with deadlines.

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[Django] #22282: models.BooleanField.blank should be 'False' if BooleanField has choices

[Django]

#22282: models.BooleanField.blank should be 'False' if BooleanField has choices
--+
 Reporter:  django@…  |  Owner:  nobody
 Type:  Uncategorized | Status:  new
Component:  Database layer (models, ORM)  |Version:  1.6
 Severity:  Normal|   Keywords:
 Triage Stage:  Unreviewed|  Has patch:  0
Easy pickings:  1 |  UI/UX:  0
--+
 There's no way to override the 'blank' property on a boolean field.
 If you look at db/models/fields/__init__.py  under
 `BooleanField.__init__()` you'll see that `blank = True` is hard coded.

 This gets messy for a couple of reasons:

 * It means that doing something like this silently fails. Either it should
 raise an error (e.g. "blank cannot be set for BooleanField") or in
 `__init__` do a check to only set `blank=True` if `kwargs.get('blank')` is
 `None`

 {{{
 class MyObj(models.Model):
 is_good = models.BooleanField(blank=False) # fails silently since
 blank = True is hard coded
 }}}


 * It makes me question the strictness of the `blank` property, if a
 boolean field in a form can validate when in fact it is `False` and not
 `None` (OK, I'm assuming somewhere that BooleanField converts a `None`
 value to `False`?

 * Most importantly (and the case where this broke for me) is when I wanted
 to do something like:


 {{{
 class MyObj(models.Model):
 is_good = models.BooleanField(choices=(
(False, "Object is Bad"),
(True, "Object is Good")
 )

 }}}

 There's no way to make sure the value is not blank.

 My simple fix was to edit `BooleanField`'s `__init__` method to do:


 {{{
 def __init__(self, *args, **kwargs):
 if not kwargs.get('choices'):
 kwargs['blank'] = True
 Field.__init__(self, *args, **kwargs)
 }}}


 But now I think about it maybe the fact that `BooleanField` assumes a
 `None` value to be `False` is another problem as well. I know why -
 because the default widget is a tickbox, which have the same state for
 `None` and `False` - but maybe the converting of `None` to `False` should
 consider the widget type?

-- 
Ticket URL: 
Django 
The Web framework for perfectionists with deadlines.

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