[soc2009/model-validation] Merged to trunk at r11603

SECURITY ALERT: Corrected regular expressions for URL and email fields.

git-svn-id: http://code.djangoproject.com/svn/django/branches/soc2009/model-validation@11617 bcc190cf-cafb-0310-a4f2-bffc1f526a37

1 files changed, 35 insertions, 0 deletions

diff --git a/docs/topics/forms/modelforms.txt b/docs/topics/forms/modelforms.txt
index add581268b..c5aa9c8a77 100644
--- a/docs/topics/forms/modelforms.txt
+++ b/docs/topics/forms/modelforms.txt
@@ -371,6 +371,35 @@ parameter when declaring the form field::
    ...     class Meta:
    ...         model = Article
 
+.. note::
+
+    If you explicitly instantiate a form field like this, Django assumes that you
+    want to completely define its behavior; therefore, default attributes (such as
+    ``max_length`` or ``required``) are not drawn from the corresponding model. If
+    you want to maintain the behavior specified in the model, you must set the
+    relevant arguments explicitly when declaring the form field.
+
+    For example, if the ``Article`` model looks like this::
+
+        class Article(models.Model):
+            headline = models.CharField(max_length=200, null=True, blank=True,
+                                        help_text="Use puns liberally")
+            content = models.TextField()
+
+    and you want to do some custom validation for ``headline``, while keeping
+    the ``blank`` and ``help_text`` values as specified, you might define
+    ``ArticleForm`` like this::
+
+        class ArticleForm(ModelForm):
+            headline = MyFormField(max_length=200, required=False,
+                                   help_text="Use puns liberally")
+
+            class Meta:
+                model = Article
+
+    See the :ref:`form field documentation <ref-forms-fields>` for more information
+    on fields and their arguments.
+
 Changing the order of fields
 ----------------------------
 
@@ -512,6 +541,12 @@ Then, pass your ``BaseAuthorFormSet`` class to the factory function::
 
     >>> AuthorFormSet = modelformset_factory(Author, formset=BaseAuthorFormSet)
 
+If you want to return a formset that doesn't include *any* pre-existing
+instances of the model, you can specify an empty QuerySet::
+
+   >>> AuthorFormSet(queryset=Author.objects.none())
+
+
 Controlling which fields are used with ``fields`` and ``exclude``
 -----------------------------------------------------------------