Skip to content

HTTPS clone URL

Subversion checkout URL

You can clone with
or
.
Download ZIP
Browse files

Fixed #8620 -- Updated the Form metaclass to support excluding fields…

… by shadowing them.
  • Loading branch information...
commit b16dd1fe019b38d0dcdf4a400e9377fb06b33178 1 parent ac5ec7b
@loic loic authored
View
5 django/forms/forms.py
@@ -90,6 +90,11 @@ def __new__(mcs, name, bases, attrs):
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
View
7 docs/ref/forms/api.txt
@@ -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
View
3  docs/releases/1.7.txt
@@ -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
^^^^^^^^^^^^^^^^^^^^
View
14 docs/topics/forms/modelforms.txt
@@ -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``
-----------------------------------------------------------------
View
23 tests/model_forms/tests.py
@@ -1815,3 +1815,26 @@ class Meta:
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'])
Please sign in to comment.
Something went wrong with that request. Please try again.