diff -r b758351d191f -r cc9b7e14412b web/lib/django/contrib/formtools/preview.py
--- a/web/lib/django/contrib/formtools/preview.py	Wed May 19 17:43:59 2010 +0200
+++ b/web/lib/django/contrib/formtools/preview.py	Tue May 25 02:43:45 2010 +0200
@@ -60,6 +60,7 @@
         f = self.form(request.POST, auto_id=AUTO_ID)
         context = {'form': f, 'stage_field': self.unused_name('stage'), 'state': self.state}
         if f.is_valid():
+            self.process_preview(request, f, context) 
             context['hash_field'] = self.unused_name('hash')
             context['hash_value'] = self.security_hash(request, f)
             return render_to_response(self.preview_template, context, context_instance=RequestContext(request))
@@ -96,6 +97,13 @@
         """
         pass
 
+    def process_preview(self, request, form, context):
+        """
+        Given a validated form, performs any extra processing before displaying
+        the preview page, and saves any extra data in context.
+        """
+        pass
+
     def security_hash(self, request, form):
         """
         Calculates the security hash for the given HttpRequest and Form instances.