Fixed #18872 -- Added prefix to FormMixin

Thanks @ibustama for the initial patch and dragonsnaker for opening the
report.

AUTHORS

@@ -249,6 +249,7 @@ answer newbie questions, and generally made Django that much better:
     martin.glueck@gmail.com
     Ben Godfrey <http://aftnn.org>
     GomoX <gomo@datafull.com>
+    Gil Gonçalves <lursty@gmail.com>
     Guilherme Mesquita Gondim <semente@taurinus.org>
     Mario Gonzalez <gonzalemario@gmail.com>
     David Gouldin <dgouldin@gmail.com>

django/views/generic/edit.py

@@ -17,6 +17,7 @@ class FormMixin(ContextMixin):
     initial = {}
     form_class = None
     success_url = None
+    prefix = None
 
     def get_initial(self):
         """
@@ -24,6 +25,12 @@ class FormMixin(ContextMixin):
         """
         return self.initial.copy()
 
+    def get_prefix(self):
+        """
+        Returns the prefix to use for forms on this view
+        """
+        return self.prefix
+
     def get_form_class(self):
         """
         Returns the form class to use in this view
@@ -40,7 +47,11 @@ class FormMixin(ContextMixin):
         """
         Returns the keyword arguments for instantiating the form.
         """
-        kwargs = {'initial': self.get_initial()}
+        kwargs = {
+            'initial': self.get_initial(),
+            'prefix': self.get_prefix(),
+        }
+
         if self.request.method in ('POST', 'PUT'):
             kwargs.update({
                 'data': self.request.POST,

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

@@ -35,6 +35,10 @@ FormMixin
 
         The URL to redirect to when the form is successfully processed.
 
+    .. attribute:: prefix
+
+        Sets the :attr:`~django.forms.Form.prefix` for the generated form.
+
     .. method:: get_initial()
 
         Retrieve initial data for the form. By default, returns a copy of

docs/releases/1.6.txt

@@ -731,6 +731,9 @@ Miscellaneous
   of the admin views. You should update your custom templates if they use the
   previous parameter name.
 
+* Added :attr:`~django.views.generic.edit.FormMixin.prefix` to allow you to
+  customize the prefix on the form.
+
 Features deprecated in 1.6
 ==========================
 

tests/generic_views/test_edit.py

@@ -7,8 +7,9 @@ from django.core.urlresolvers import reverse
 from django import forms
 from django.test import TestCase
 from django.utils.unittest import expectedFailure
+from django.test.client import RequestFactory
 from django.views.generic.base import View
-from django.views.generic.edit import FormMixin, CreateView, UpdateView
+from django.views.generic.edit import FormMixin, CreateView
 
 from . import views
 from .models import Artist, Author
@@ -22,6 +23,24 @@ class FormMixinTests(TestCase):
         initial_2 = FormMixin().get_initial()
         self.assertNotEqual(initial_1, initial_2)
 
+    def test_get_prefix(self):
+        """ Test prefix can be set (see #18872) """
+        test_string = 'test'
+
+        rf = RequestFactory()
+        get_request = rf.get('/')
+
+        class TestFormMixin(FormMixin):
+            request = get_request
+
+        default_kwargs = TestFormMixin().get_form_kwargs()
+        self.assertEqual(None, default_kwargs.get('prefix'))
+
+        set_mixin = TestFormMixin()
+        set_mixin.prefix = test_string
+        set_kwargs = set_mixin.get_form_kwargs()
+        self.assertEqual(test_string, set_kwargs.get('prefix'))
+
 
 class BasicFormTests(TestCase):
     urls = 'generic_views.urls'