--- a/web/form.py	Wed Mar 24 10:23:31 2010 +0100
+++ b/web/form.py	Wed Apr 28 11:54:13 2010 +0200
@@ -1,9 +1,22 @@
+# copyright 2003-2010 LOGILAB S.A. (Paris, FRANCE), all rights reserved.
+# contact http://www.logilab.fr/ -- mailto:contact@logilab.fr
+#
+# This file is part of CubicWeb.
+#
+# CubicWeb is free software: you can redistribute it and/or modify it under the
+# terms of the GNU Lesser General Public License as published by the Free
+# Software Foundation, either version 2.1 of the License, or (at your option)
+# any later version.
+#
+# logilab-common is distributed in the hope that it will be useful, but WITHOUT
+# ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or FITNESS
+# FOR A PARTICULAR PURPOSE.  See the GNU Lesser General Public License for more
+# details.
+#
+# You should have received a copy of the GNU Lesser General Public License along
+# with CubicWeb.  If not, see <http://www.gnu.org/licenses/>.
 """abstract form classes for CubicWeb web client
 
-:organization: Logilab
-:copyright: 2001-2010 LOGILAB S.A. (Paris, FRANCE), license is LGPL v2.
-:contact: http://www.logilab.fr/ -- mailto:contact@logilab.fr
-:license: GNU Lesser General Public License, v2.1 - http://www.gnu.org/licenses
 """
 __docformat__ = "restructuredtext en"
 
@@ -14,8 +27,7 @@
 
 from cubicweb.appobject import AppObject
 from cubicweb.view import NOINDEX, NOFOLLOW
-from cubicweb.web import httpcache, formfields, controller
-
+from cubicweb.web import httpcache, formfields, controller, formwidgets as fwdgs
 
 class FormViewMixIn(object):
     """abstract form view mix-in"""
@@ -137,8 +149,9 @@
 
     @iclassmethod
     def field_by_name(cls_or_self, name, role=None):
-        """return field with the given name and role.
-        Raise FieldNotFound if the field can't be found.
+        """Return field with the given name and role.
+
+        Raise :exc:`FieldNotFound` if the field can't be found.
         """
         for field in cls_or_self._fieldsattr():
             if field.name == name and field.role == role:
@@ -147,31 +160,49 @@
 
     @iclassmethod
     def fields_by_name(cls_or_self, name, role=None):
-        """return a list of fields with the given name and role"""
+        """Return a list of fields with the given name and role."""
         return [field for field in cls_or_self._fieldsattr()
                 if field.name == name and field.role == role]
 
     @iclassmethod
     def remove_field(cls_or_self, field):
-        """remove a field from form class or instance"""
+        """Remove the given field."""
         cls_or_self._fieldsattr().remove(field)
 
     @iclassmethod
     def append_field(cls_or_self, field):
-        """append a field to form class or instance"""
+        """Append the given field."""
         cls_or_self._fieldsattr().append(field)
 
     @iclassmethod
-    def insert_field_before(cls_or_self, new_field, name, role='subject'):
-        field = cls_or_self.field_by_name(name, role)
+    def insert_field_before(cls_or_self, field, name, role=None):
+        """Insert the given field before the field of given name and role."""
+        bfield = cls_or_self.field_by_name(name, role)
         fields = cls_or_self._fieldsattr()
-        fields.insert(fields.index(field), new_field)
+        fields.insert(fields.index(bfield), field)
+
+    @iclassmethod
+    def insert_field_after(cls_or_self, field, name, role=None):
+        """Insert the given field after the field of given name and role."""
+        afield = cls_or_self.field_by_name(name, role)
+        fields = cls_or_self._fieldsattr()
+        fields.insert(fields.index(afield)+1, field)
 
     @iclassmethod
-    def insert_field_after(cls_or_self, new_field, name, role='subject'):
-        field = cls_or_self.field_by_name(name, role)
-        fields = cls_or_self._fieldsattr()
-        fields.insert(fields.index(field)+1, new_field)
+    def add_hidden(cls_or_self, name, value=None, **kwargs):
+        """Append an hidden field to the form. `name`, `value` and extra keyword
+        arguments will be given to the field constructor. The inserted field is
+        returned.
+        """
+        kwargs.setdefault('ignore_req_params', True)
+        kwargs.setdefault('widget', fwdgs.HiddenInput)
+        field = formfields.StringField(name=name, value=value, **kwargs)
+        if 'id' in kwargs:
+            # by default, hidden input don't set id attribute. If one is
+            # explicitly specified, ensure it will be set
+            field.widget.setdomid = True
+        cls_or_self.append_field(field)
+        return field
 
     def session_key(self):
         """return the key that may be used to store / retreive data about a