Ticket #4572: form_for_instance_patch.txt

Index: /home/tobryan1/workspace/django/docs/newforms.txt
===================================================================
--- /home/tobryan1/workspace/django/docs/newforms.txt   (revision 5478)
+++ /home/tobryan1/workspace/django/docs/newforms.txt   (working copy)
@@ -1617,6 +1617,28 @@
 this data is not bound to the form. You will need to bind data to the
 form before the form can be saved.
 
+So, to edit an object already in the database, use the following pattern. In
+the GET branch of your view, instantiate a form using ``form_for_instance`` and
+display it on the page. In the POST branch, again use ``form_for_instance``, and
+then bind the data to the form. Here's a short example:
+
+       #typical view pattern
+       def edit_foo_by_id(request, foo_id):
+               foo = Foo.objects.get_object_or_404(id=foo_id)
+               FooForm = form_for_instance(foo)
+               if request.POST:
+                       data = request.POST.copy()
+                       f = FooForm(data)
+                       if f.is_valid():
+                               f.save()
+                               ... #probably redirect to result page
+                       else:
+                               #handle validation error
+               else:
+                       #GET
+                       f = FooForm()
+                       ... #return response and display form
+                       
 When you call ``save()`` on a form created by ``form_for_instance()``,
 the database instance will be updated. As in ``form_for_model()``, ``save()``
 will raise ``ValueError`` if the data doesn't validate.