diff --git a/openerp/osv/orm.py b/openerp/osv/orm.py
index 2ced177fdb9..c8df66c55da 100644
--- a/openerp/osv/orm.py
+++ b/openerp/osv/orm.py
@@ -52,6 +52,7 @@ import re
 import time
 import traceback
 import types
+import simplejson
 
 import openerp.netsvc as netsvc
 from lxml import etree
@@ -75,6 +76,88 @@ module_class_list = {}
 # Super-user identifier (aka Administrator aka root)
 ROOT_USER_ID = 1
 
+def transfer_field_to_modifiers(field, modifiers):
+    for a in ('invisible', 'readonly', 'required'):
+        if field.get(a):
+            modifiers[a] = bool(field.get(a))
+
+
+# Don't deal with groups, it is done by check_group().
+# Need the context to evaluate the invisible attribute on tree views.
+# For non-tree views, the context shouldn't be given.
+def transfer_node_to_modifiers(node, modifiers, context=None, in_tree_view=False):
+    if node.get('attrs'):
+        modifiers.update(eval(node.get('attrs')))
+
+    if node.get('states'):
+        if 'invisible' in modifiers and isinstance(modifiers['invisible'], list):
+             # TODO combine with AND or OR, use implicit AND for now.
+             modifiers['invisible'].append(('state', 'not in', node.get('states').split(',')))
+        else:
+             modifiers['invisible'] = [('state', 'not in', node.get('states').split(','))]
+
+    for a in ('invisible', 'readonly', 'required'):
+        if node.get(a):
+            v = bool(eval(node.get(a), {'context': context or {}}))
+            if in_tree_view and a == 'invisible':
+                # Invisible in a tree view has a specific meaning, make it a
+                # new key in the modifiers attribute.
+                modifiers['tree_invisible'] = v
+            elif v or (a not in modifiers or not isinstance(modifiers[a], list)):
+                # Don't set the attribute to False if a dynamic value was
+                # provided (i.e. a domain from attrs or states).
+                modifiers[a] = v
+
+
+def simplify_modifiers(modifiers):
+    for a in ('invisible', 'readonly', 'required'):
+        if a in modifiers and not modifiers[a]:
+            del modifiers[a]
+
+
+def transfer_modifiers_to_node(modifiers, node):
+    if modifiers:
+        simplify_modifiers(modifiers)
+        node.set('modifiers', simplejson.dumps(modifiers))
+
+
+def test_modifiers(what, expected):
+    modifiers = {}
+    if isinstance(what, basestring):
+        node = etree.fromstring(what)
+        transfer_node_to_modifiers(node, modifiers)
+        simplify_modifiers(modifiers)
+        json = simplejson.dumps(modifiers)
+        assert json == expected, "%s != %s" % (json, expected)
+    elif isinstance(what, dict):
+        transfer_field_to_modifiers(what, modifiers)
+        simplify_modifiers(modifiers)
+        json = simplejson.dumps(modifiers)
+        assert json == expected, "%s != %s" % (json, expected)
+
+
+# To use this test:
+# import openerp
+# openerp.osv.orm.modifiers_tests()
+def modifiers_tests():
+    test_modifiers('<field name="a"/>', '{}')
+    test_modifiers('<field name="a" invisible="1"/>', '{"invisible": true}')
+    test_modifiers('<field name="a" readonly="1"/>', '{"readonly": true}')
+    test_modifiers('<field name="a" required="1"/>', '{"required": true}')
+    test_modifiers('<field name="a" invisible="0"/>', '{}')
+    test_modifiers('<field name="a" readonly="0"/>', '{}')
+    test_modifiers('<field name="a" required="0"/>', '{}')
+    test_modifiers('<field name="a" invisible="1" required="1"/>', '{"invisible": true, "required": true}') # TODO order is not guaranteed
+    test_modifiers('<field name="a" invisible="1" required="0"/>', '{"invisible": true}')
+    test_modifiers('<field name="a" invisible="0" required="1"/>', '{"required": true}')
+    test_modifiers("""<field name="a" attrs="{'invisible': [('b', '=', 'c')]}"/>""", '{"invisible": [["b", "=", "c"]]}')
+
+    # The dictionary is supposed to be the result of fields_get().
+    test_modifiers({}, '{}')
+    test_modifiers({"invisible": True}, '{"invisible": true}')
+    test_modifiers({"invisible": False}, '{}')
+    
+
 def check_object_name(name):
     """ Check if the given name is a valid openerp object name.
 
@@ -1346,13 +1429,26 @@ class orm_template(object):
     def view_header_get(self, cr, user, view_id=None, view_type='form', context=None):
         return False
 
-    def __view_look_dom(self, cr, user, node, view_id, context=None):
+    def __view_look_dom(self, cr, user, node, view_id, in_tree_view, model_fields, context=None):
+        """ Return the description of the fields in the node.
+
+        In a normal call to this method, node is a complete view architecture
+        but it is actually possible to give some sub-node (this is used so
+        that the method can call itself recursively).
+
+        Originally, the field descriptions are drawn from the node itself.
+        But there is now some code calling fields_get() in order to merge some
+        of those information in the architecture.
+
+        """
         if context is None:
             context = {}
         result = False
         fields = {}
         children = True
 
+        modifiers = {}
+
         def encode(s):
             if isinstance(s, unicode):
                 return s.encode('utf8')
@@ -1366,6 +1462,7 @@ class orm_template(object):
                 can_see = any(access_pool.check_groups(cr, user, group) for group in groups)
                 if not can_see:
                     node.set('invisible', '1')
+                    modifiers['invisible'] = True
                     if 'attrs' in node.attrib:
                         del(node.attrib['attrs']) #avoid making field visible later
                 del(node.attrib['groups'])
@@ -1437,10 +1534,14 @@ class orm_template(object):
                             attrs['selection'].append((False, ''))
                 fields[node.get('name')] = attrs
 
+                field = model_fields[node.get('name')]
+                transfer_field_to_modifiers(field, modifiers)
+
         elif node.tag in ('form', 'tree'):
             result = self.view_header_get(cr, user, False, node.tag, context)
             if result:
                 node.set('string', result)
+            in_tree_view = node.tag == 'tree'
 
         elif node.tag == 'calendar':
             for additional_field in ('date_start', 'date_delay', 'date_stop', 'color'):
@@ -1449,6 +1550,12 @@ class orm_template(object):
 
         check_group(node)
 
+        # The view architeture overrides the python model.
+        # Get the attrs before they are (possibly) deleted by check_group below
+        transfer_node_to_modifiers(node, modifiers, context, in_tree_view)
+
+        # TODO remove attrs couterpart in modifiers when invisible is true ?
+
         # translate view
         if 'lang' in context:
             if node.get('string') and not result:
@@ -1474,8 +1581,9 @@ class orm_template(object):
 
         for f in node:
             if children or (node.tag == 'field' and f.tag in ('filter','separator')):
-                fields.update(self.__view_look_dom(cr, user, f, view_id, context))
+                fields.update(self.__view_look_dom(cr, user, f, view_id, in_tree_view, model_fields, context))
 
+        transfer_modifiers_to_node(modifiers, node)
         return fields
 
     def _disable_workflow_buttons(self, cr, user, node):
@@ -1504,19 +1612,32 @@ class orm_template(object):
         return node
 
     def __view_look_dom_arch(self, cr, user, node, view_id, context=None):
-        fields_def = self.__view_look_dom(cr, user, node, view_id, context=context)
-        node = self._disable_workflow_buttons(cr, user, node)
-        arch = etree.tostring(node, encoding="utf-8").replace('\t', '')
+        """ Return an architecture and a description of all the fields.
+
+        The field description combines the result of fields_get() and
+        __view_look_dom().
+
+        :param node: the architecture as as an etree
+        :return: a tuple (arch, fields) where arch is the given node as a
+            string and fields is the description of all the fields.
+
+        """
         fields = {}
         if node.tag == 'diagram':
             if node.getchildren()[0].tag == 'node':
-                node_fields = self.pool.get(node.getchildren()[0].get('object')).fields_get(cr, user, fields_def.keys(), context)
+                node_fields = self.pool.get(node.getchildren()[0].get('object')).fields_get(cr, user, None, context)
                 fields.update(node_fields)
             if node.getchildren()[1].tag == 'arrow':
-                arrow_fields = self.pool.get(node.getchildren()[1].get('object')).fields_get(cr, user, fields_def.keys(), context)
+                arrow_fields = self.pool.get(node.getchildren()[1].get('object')).fields_get(cr, user, None, context)
                 fields.update(arrow_fields)
         else:
-            fields = self.fields_get(cr, user, fields_def.keys(), context)
+            fields = self.fields_get(cr, user, None, context)
+        fields_def = self.__view_look_dom(cr, user, node, view_id, False, fields, context=context)
+        node = self._disable_workflow_buttons(cr, user, node)
+        arch = etree.tostring(node, encoding="utf-8").replace('\t', '')
+        for k in fields.keys():
+            if k not in fields_def:
+                del fields[k]
         for field in fields_def:
             if field == 'id':
                 # sometime, the view may contain the (invisible) field 'id' needed for a domain (when 2 objects have cross references)
@@ -1537,6 +1658,7 @@ class orm_template(object):
     def __get_default_calendar_view(self):
         """Generate a default calendar view (For internal use only).
         """
+        # TODO could return an etree instead of a string
 
         arch = ('<?xml version="1.0" encoding="utf-8"?>\n'
                 '<calendar string="%s"') % (self._description)
@@ -1604,6 +1726,7 @@ class orm_template(object):
         for field_name in fields_to_search:
             field_group.append(etree.Element("field", attrib={'name': field_name}))
 
+        #TODO tostring can be removed as fromstring is call directly after...
         return etree.tostring(search_view, encoding="utf-8").replace('\t', '')
 
     #