Commit b16dd1fe authored by Loic Bistuer's avatar Loic Bistuer
Browse files

Fixed #8620 -- Updated the Form metaclass to support excluding fields by shadowing them.

parent ac5ec7b8

django/forms/forms.py

+5 −0
Original line number Diff line number Diff line
@@ -90,6 +90,11 @@ class DeclarativeFieldsMetaclass(MediaDefiningClass): 
            if hasattr(base, 'declared_fields'):

                declared_fields.update(base.declared_fields)



            # Field shadowing.

            for attr in base.__dict__.keys():

                if attr in declared_fields:

                    declared_fields.pop(attr)



        new_class.base_fields = declared_fields

        new_class.declared_fields = declared_fields

docs/ref/forms/api.txt

+7 −0
Original line number Diff line number Diff line
@@ -854,6 +854,13 @@ classes:: 
    <li>Instrument: <input type="text" name="instrument" /></li>

    <li>Haircut type: <input type="text" name="haircut_type" /></li>



.. versionadded:: 1.7



* It's possible to opt-out from a ``Field`` inherited from a parent class by

  shadowing it. While any non-``Field`` value works for this purpose, it's

  recommended to use ``None`` to make it explicit that a field is being

  nullified.



.. _form-prefix:



Prefixes for forms

docs/releases/1.7.txt

+3 −0
Original line number Diff line number Diff line
@@ -293,6 +293,9 @@ Forms 
  inheriting from both ``Form`` and ``ModelForm`` simultaneously have been

  removed as long as ``ModelForm`` appears first in the MRO.



* It's now possible to opt-out from a ``Form`` field declared in a parent class

  by shadowing it with a non-``Field`` value.



Internationalization

^^^^^^^^^^^^^^^^^^^^

docs/topics/forms/modelforms.txt

+14 −0
Original line number Diff line number Diff line
@@ -651,6 +651,18 @@ There are a couple of things to note, however. 
  because these classes rely on different metaclasses and a class can only have

  one metaclass.



.. versionadded:: 1.7



* It's possible to opt-out from a ``Field`` inherited from a parent class by

  shadowing it. While any non-``Field`` value works for this purpose, it's

  recommended to use ``None`` to make it explicit that a field is being

  nullified.



  You can only use this technique to opt out from a field defined declaratively

  by a parent class; it won't prevent the ``ModelForm`` metaclass from generating

  a default field. To opt-out from default fields, see

  :ref:`controlling-fields-with-fields-and-exclude`.



.. _modelforms-factory:



ModelForm factory function
@@ -749,6 +761,8 @@ instances of the model, you can specify an empty QuerySet:: 
   >>> AuthorFormSet(queryset=Author.objects.none())





.. _controlling-fields-with-fields-and-exclude:



Controlling which fields are used with ``fields`` and ``exclude``

-----------------------------------------------------------------

tests/model_forms/tests.py

+23 −0
Original line number Diff line number Diff line
@@ -1815,3 +1815,26 @@ class ModelFormInheritanceTests(TestCase): 
                fields = '__all__'



        self.assertEqual(list(ModelForm().fields.keys()), ['name', 'age'])



    def test_field_shadowing(self):

        class ModelForm(forms.ModelForm):

            class Meta:

                model = Writer

                fields = '__all__'



        class Mixin(object):

            age = None



        class Form(forms.Form):

            age = forms.IntegerField()



        class Form2(forms.Form):

            foo = forms.IntegerField()



        self.assertEqual(list(ModelForm().fields.keys()), ['name'])

        self.assertEqual(list(type(str('NewForm'), (Mixin, Form), {})().fields.keys()), [])

        self.assertEqual(list(type(str('NewForm'), (Form2, Mixin, Form), {})().fields.keys()), ['foo'])

        self.assertEqual(list(type(str('NewForm'), (Mixin, ModelForm, Form), {})().fields.keys()), ['name'])

        self.assertEqual(list(type(str('NewForm'), (ModelForm, Mixin, Form), {})().fields.keys()), ['name'])

        self.assertEqual(list(type(str('NewForm'), (ModelForm, Form, Mixin), {})().fields.keys()), ['name', 'age'])

        self.assertEqual(list(type(str('NewForm'), (ModelForm, Form), {'age': None})().fields.keys()), ['name'])