Fixed #24643 -- Added get_context_data() method to FormMixin

django/views/generic/edit.py

@@ -112,7 +112,14 @@ class FormMixin(six.with_metaclass(FormMixinBase, ContextMixin)):
         If the form is invalid, re-render the context data with the
         data-filled form and errors.
         """
-        return self.render_to_response(self.get_context_data(form=form))
+        return self.render_to_response(self.get_context_data())
+
+    def get_context_data(self, **kwargs):
+        """
+        Insert the form into the context dict.
+        """
+        kwargs.setdefault('form', self.get_form())
+        return super(FormMixin, self).get_context_data(**kwargs)
 
 
 class ModelFormMixin(FormMixin, SingleObjectMixin):
@@ -202,8 +209,7 @@ class ProcessFormView(View):
         """
         Handles GET requests and instantiates a blank version of the form.
         """
-        form = self.get_form()
-        return self.render_to_response(self.get_context_data(form=form))
+        return self.render_to_response(self.get_context_data())
 
     def post(self, request, *args, **kwargs):
         """

docs/ref/class-based-views/flattened-index.txt

@@ -168,7 +168,7 @@ FormView
 * :meth:`~django.views.generic.edit.FormMixin.form_invalid`
 * :meth:`~django.views.generic.edit.FormMixin.form_valid`
 * :meth:`~django.views.generic.edit.ProcessFormView.get`
-* :meth:`~django.views.generic.base.ContextMixin.get_context_data`
+* :meth:`~django.views.generic.edit.FormMixin.get_context_data`
 * :meth:`~django.views.generic.edit.FormMixin.get_form`
 * :meth:`~django.views.generic.edit.FormMixin.get_form_kwargs`
 * :meth:`~django.views.generic.base.View.http_method_not_allowed`
@@ -207,7 +207,7 @@ CreateView
 * :meth:`~django.views.generic.edit.FormMixin.form_invalid`
 * :meth:`~django.views.generic.edit.ModelFormMixin.form_valid`
 * :meth:`~django.views.generic.edit.ProcessFormView.get`
-* :meth:`~django.views.generic.base.ContextMixin.get_context_data`
+* :meth:`~django.views.generic.edit.FormMixin.get_context_data`
 * :meth:`~django.views.generic.edit.FormMixin.get_form`
 * :meth:`~django.views.generic.edit.ModelFormMixin.get_form_kwargs`
 * :meth:`~django.views.generic.detail.SingleObjectMixin.get_object`
@@ -249,7 +249,7 @@ UpdateView
 * :meth:`~django.views.generic.edit.FormMixin.form_invalid`
 * :meth:`~django.views.generic.edit.ModelFormMixin.form_valid`
 * :meth:`~django.views.generic.edit.ProcessFormView.get`
-* :meth:`~django.views.generic.base.ContextMixin.get_context_data`
+* :meth:`~django.views.generic.edit.FormMixin.get_context_data`
 * :meth:`~django.views.generic.edit.FormMixin.get_form`
 * :meth:`~django.views.generic.edit.ModelFormMixin.get_form_kwargs`
 * :meth:`~django.views.generic.detail.SingleObjectMixin.get_object`

docs/ref/class-based-views/mixins-editing.txt

@@ -91,6 +91,13 @@ FormMixin
 
         Renders a response, providing the invalid form as context.
 
+    .. method:: get_context_data(**kwargs)
+
+        .. versionadded:: 1.9
+
+        Calls :meth:`get_form` and adds the result to the context data with the
+        name 'form'.
+
 ModelFormMixin
 --------------
 
@@ -214,8 +221,13 @@ ProcessFormView
 
     .. method:: get(request, *args, **kwargs)
 
-        Constructs a form, then renders a response using a context that
-        contains that form.
+        Renders a response using a context created with
+        :meth:`~django.views.generic.edit.FormMixin.get_context_data`.
+
+        .. versionchanged:: 1.9
+
+            Construction of the form was moved from this method to
+            :meth:`~django.views.generic.edit.FormMixin.get_context_data`.
 
     .. method:: post(request, *args, **kwargs)
 

docs/releases/1.9.txt

@@ -407,6 +407,13 @@ Miscellaneous
 * ``CommaSeparatedIntegerField`` validation has been refined to forbid values
   like ``','``, ``',1'``, and ``'1,,2'``.
 
+* Form initialization was moved from the :meth:`ProcessFormView.get()
+  <django.views.generic.edit.ProcessFormView.get>` method to the new
+  :meth:`FormMixin.get_context_data()
+  <django.views.generic.edit.FormMixin.get_context_data>` method. This may be
+  backwards incompatible if you have overridden the ``get_context_data()``
+  method without calling ``super()``.
+
 .. _deprecated-features-1.9:
 
 Features deprecated in 1.9

tests/generic_views/test_edit.py

@@ -81,6 +81,13 @@ class FormMixinTests(TestCase):
             MissingDefaultValue().get_form(), forms.Form,
         )
 
+    def test_get_context_data(self):
+        class FormContext(FormMixin):
+            request = RequestFactory().get('/')
+            form_class = forms.Form
+
+        self.assertIsInstance(FormContext().get_context_data()['form'], forms.Form)
+
 
 @override_settings(ROOT_URLCONF='generic_views.urls')
 class BasicFormTests(TestCase):