From e58c75fbdfbc2f11a1d3d6fd949f7375199c6663 Mon Sep 17 00:00:00 2001
From: Brian Rosner <brosner@gmail.com>
Date: Wed, 31 Mar 2010 07:43:52 +0000
Subject: [PATCH] Restored pre-r10062 behavior allowing None from
 formfield_callback to exclude itself from the form

git-svn-id: http://code.djangoproject.com/svn/django/trunk@12891 bcc190cf-cafb-0310-a4f2-bffc1f526a37
---
 django/forms/models.py                 |  8 ++++++-
 tests/modeltests/model_forms/models.py | 29 ++++++++++++++++++++++++++
 2 files changed, 36 insertions(+), 1 deletion(-)

diff --git a/django/forms/models.py b/django/forms/models.py
index 608b87bd33..42de898aa7 100644
--- a/django/forms/models.py
+++ b/django/forms/models.py
@@ -167,6 +167,7 @@ def fields_for_model(model, fields=None, exclude=None, widgets=None, formfield_c
     in the ``fields`` argument.
     """
     field_list = []
+    ignored = []
     opts = model._meta
     for f in opts.fields + opts.many_to_many:
         if not f.editable:
@@ -182,9 +183,14 @@ def fields_for_model(model, fields=None, exclude=None, widgets=None, formfield_c
         formfield = formfield_callback(f, **kwargs)
         if formfield:
             field_list.append((f.name, formfield))
+        else:
+            ignored.append(f.name)
     field_dict = SortedDict(field_list)
     if fields:
-        field_dict = SortedDict([(f, field_dict.get(f)) for f in fields if (not exclude) or (exclude and f not in exclude)])
+        field_dict = SortedDict(
+            [(f, field_dict.get(f)) for f in fields
+                if ((not exclude) or (exclude and f not in exclude)) and (f not in ignored)]
+        )
     return field_dict
 
 class ModelFormOptions(object):
diff --git a/tests/modeltests/model_forms/models.py b/tests/modeltests/model_forms/models.py
index 998f212fae..e7c4022f6f 100644
--- a/tests/modeltests/model_forms/models.py
+++ b/tests/modeltests/model_forms/models.py
@@ -220,6 +220,22 @@ class BigInt(models.Model):
     def __unicode__(self):
         return unicode(self.biggie)
 
+class MarkupField(models.CharField):
+    def __init__(self, *args, **kwargs):
+        kwargs["max_length"] = 20
+        super(MarkupField, self).__init__(*args, **kwargs)
+
+    def formfield(self, **kwargs):
+        # don't allow this field to be used in form (real use-case might be
+        # that you know the markup will always be X, but it is among an app
+        # that allows the user to say it could be something else)
+        # regressed at r10062
+        return None
+
+class CustomFieldForExclusionModel(models.Model):
+    name = models.CharField(max_length=10)
+    markup = MarkupField()
+
 __test__ = {'API_TESTS': """
 >>> from django import forms
 >>> from django.forms.models import ModelForm, model_to_dict
@@ -1540,6 +1556,19 @@ ValidationError: [u'Select a valid choice. z is not one of the available choices
 <tr><th><label for="id_description">Description:</label></th><td><input type="text" name="description" id="id_description" /></td></tr>
 <tr><th><label for="id_url">The URL:</label></th><td><input id="id_url" type="text" name="url" maxlength="40" /></td></tr>
 
+# Model field that returns None to exclude itself with explicit fields ########
+
+>>> class CustomFieldForExclusionForm(ModelForm):
+...     class Meta:
+...         model = CustomFieldForExclusionModel
+...         fields = ['name', 'markup']
+
+>>> CustomFieldForExclusionForm.base_fields.keys()
+['name']
+
+>>> print CustomFieldForExclusionForm()
+<tr><th><label for="id_name">Name:</label></th><td><input id="id_name" type="text" name="name" maxlength="10" /></td></tr>
+
 # Clean up
 >>> import shutil
 >>> shutil.rmtree(temp_storage_dir)