Don't explode in non_field_errors with FormSets.

betterforms/multiform.py

@@ -71,6 +71,8 @@ def is_valid(self):
     def non_field_errors(self):
         return ErrorList(chain.from_iterable(
             form.non_field_errors() for form in self.forms.values()
+            # FormSets don't have non_field_errors errors
+            if hasattr(form, 'non_field_errors')
         ))
 
     def as_table(self):

docs/multiform.rst

@@ -289,6 +289,21 @@ API Reference
 
     .. method:: non_field_errors
 
+        .. note::
+
+            :class:`FormSets <django:django.forms.formsets.BaseFormSet>` do not
+            provide :meth:`non_field_errors`, they provide
+            :meth:`non_form_errors() <django:django.forms.formsets.BaseFormSet.non_form_errors>`,
+            if you put a :class:`FormSet
+            <django:django.forms.formsets.BaseFormSet>` in your
+            :attr:`form_classes`, the output of :meth:`non_field_errors` **does
+            not** include the
+            :meth:`non_form_errors() <django:django.forms.formsets.BaseFormSet.non_form_errors>`,
+            from the formset, you will
+            need to call
+            :meth:`non_form_errors() <django:django.forms.formsets.BaseFormSet.non_form_errors>`,
+            yourself.
+
     .. method:: as_table
 
     .. method:: as_ul

tests/tests/forms.py

@@ -4,12 +4,13 @@
     from django.utils.datastructures import SortedDict as OrderedDict  # NOQA
 
 from django import forms
+from django.forms.models import inlineformset_factory
 from django.contrib.admin import widgets as admin_widgets
 from django.core.exceptions import ValidationError
 
 from betterforms.multiform import MultiForm, MultiModelForm
 
-from .models import User, Profile, Badge, Author
+from .models import User, Profile, Badge, Author, Book, BookImage
 
 
 class UserForm(forms.ModelForm):
@@ -100,3 +101,29 @@ class ManyToManyMultiForm(MultiModelForm):
         'badge': BadgeForm,
         'author': AuthorForm,
     }
+
+
+class BookForm(forms.ModelForm):
+    class Meta:
+        model = Book
+        fields = ('name',)
+
+
+BookImageFormSet = inlineformset_factory(Book, BookImage, fields=('name',))
+
+
+class BookMultiForm(MultiModelForm):
+    form_classes = {
+        'book': BookForm,
+        'error': RaisesErrorForm,
+        'images': BookImageFormSet,
+    }
+
+    def __init__(self, *args, **kwargs):
+        instance = kwargs.pop('instance', None)
+        if instance is not None:
+            kwargs['instance'] = {
+                'book': instance,
+                'images': instance,
+            }
+        super(BookMultiForm, self).__init__(*args, **kwargs)

tests/tests/models.py

@@ -24,3 +24,8 @@ class Author(models.Model):
 
 class Book(models.Model):
     name = models.CharField(max_length=255)
+
+
+class BookImage(models.Model):
+    book = models.ForeignKey(Book, related_name='images')
+    name = models.CharField(max_length=255)

tests/tests/tests.py

@@ -15,7 +15,7 @@
 from .models import User, Profile, Badge, Book
 from .forms import (
     UserProfileMultiForm, BadgeMultiForm, ErrorMultiForm,
-    MixedForm, NeedsFileField, ManyToManyMultiForm,
+    MixedForm, NeedsFileField, ManyToManyMultiForm, BookMultiForm,
 )
 
 
@@ -244,3 +244,14 @@ def test_works_with_create_view_post(self):
         resp = viewfn(request)
         self.assertEqual(resp.status_code, 302)
         self.assertEqual(Badge.objects.count(), 2)
+
+    def test_non_field_errors_with_formset(self):
+        form = BookMultiForm({
+            'book-name': '',
+            'images-0-name': '',
+            'images-TOTAL_FORMS': '3',
+            'images-INITIAL_FORMS': '0',
+            'images-MAX_NUM_FORMS': '1000',
+        })
+        # assertDoesntRaise AttributeError
+        self.assertEqual(form.non_field_errors().as_text(), '* It broke')