--- a/web/form.py	Tue Sep 29 12:38:48 2009 +0200
+++ b/web/form.py	Tue Sep 29 12:39:32 2009 +0200
@@ -7,6 +7,8 @@
 """
 __docformat__ = "restructuredtext en"
 
+from logilab.common.decorators import iclassmethod
+
 from cubicweb.appobject import AppObject
 from cubicweb.view import NOINDEX, NOFOLLOW
 from cubicweb.common import tags
@@ -205,3 +207,58 @@
 class Form(FormMixIn, AppObject):
     __metaclass__ = metafieldsform
     __registry__ = 'forms'
+
+    parent_form = None
+
+    @property
+    def root_form(self):
+        """return the root form"""
+        if self.parent_form is None:
+            return self
+        return self.parent_form.root_form
+
+    @iclassmethod
+    def _fieldsattr(cls_or_self):
+        if isinstance(cls_or_self, type):
+            fields = cls_or_self._fields_
+        else:
+            fields = cls_or_self.fields
+        return fields
+
+    @iclassmethod
+    def field_by_name(cls_or_self, name, role='subject'):
+        """return field with the given name and role.
+        Raise FieldNotFound if the field can't be found.
+        """
+        for field in cls_or_self._fieldsattr():
+            if field.name == name and field.role == role:
+                return field
+        raise FieldNotFound(name)
+
+    @iclassmethod
+    def fields_by_name(cls_or_self, name, role='subject'):
+        """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"""
+        cls_or_self._fieldsattr().remove(field)
+
+    @iclassmethod
+    def append_field(cls_or_self, field):
+        """append a field to form class or instance"""
+        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)
+        fields = cls_or_self._fieldsattr()
+        fields.insert(fields.index(field), new_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)

--- a/web/views/forms.py	Tue Sep 29 12:38:48 2009 +0200
+++ b/web/views/forms.py	Tue Sep 29 12:39:32 2009 +0200
@@ -10,7 +10,6 @@
 from warnings import warn
 
 from logilab.common.compat import any
-from logilab.common.decorators import iclassmethod
 
 from cubicweb.selectors import non_final_entity, match_kwargs, one_line_rset
 from cubicweb.web import INTERNAL_FIELD_VALUE, eid_param
@@ -101,52 +100,6 @@
         if 'domid' in kwargs:# session key changed
             self.restore_previous_post(self.session_key())
 
-    @iclassmethod
-    def _fieldsattr(cls_or_self):
-        if isinstance(cls_or_self, type):
-            fields = cls_or_self._fields_
-        else:
-            fields = cls_or_self.fields
-        return fields
-
-    @iclassmethod
-    def field_by_name(cls_or_self, name, role='subject'):
-        """return field with the given name and role.
-        Raise FieldNotFound if the field can't be found.
-        """
-        for field in cls_or_self._fieldsattr():
-            if field.name == name and field.role == role:
-                return field
-        raise form.FieldNotFound(name)
-
-    @iclassmethod
-    def fields_by_name(cls_or_self, name, role='subject'):
-        """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"""
-        cls_or_self._fieldsattr().remove(field)
-
-    @iclassmethod
-    def append_field(cls_or_self, field):
-        """append a field to form class or instance"""
-        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)
-        fields = cls_or_self._fieldsattr()
-        fields.insert(fields.index(field), new_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)
-
     @property
     def form_needs_multipart(self):
         """true if the form needs enctype=multipart/form-data"""