Ticket #4572: form_for_instance.patch

home/tobryan1/workspace/django/docs/newforms.txt

@@ -1617 +1617 @@
 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. Get
+the object for which you want to create a form in and use the
+`form_for_instance` function to create a Form class. In the GET branch,
+instantiate the class with no data, and it will use the values from the
+instance as defaults. In the POST branch, instantiate the form using the POST
+data and these will be saved to the database. Here's a short example:
+
+        #typical view pattern
+        def edit_foo_by_id(request, foo_id):
+                foo = get_object_or_404(Foo, id=foo_id)
+                FooForm = form_for_instance(foo)
+                if request.method == '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.