diff -r e95cfd5eca61 -r 40a49f4350a5 entities/authobjs.py
--- a/entities/authobjs.py	Tue Sep 13 14:54:00 2011 +0200
+++ b/entities/authobjs.py	Tue Sep 13 15:40:06 2011 +0200
@@ -29,6 +29,22 @@
     fetch_attrs, fetch_order = fetch_config(['name'])
     fetch_unrelated_order = fetch_order
 
+    def grant_permission(self, entity, pname, plabel=None):
+        """grant local `pname` permission on `entity` to this group using
+        :class:`CWPermission`.
+
+        If a similar permission already exists, add the group to it, else create
+        a new one.
+        """
+        if not self._cw.execute(
+            'SET X require_group G WHERE E eid %(e)s, G eid %(g)s, '
+            'E require_permission X, X name %(name)s, X label %(label)s',
+            {'e': entity.eid, 'g': self.eid,
+             'name': pname, 'label': plabel}):
+            self._cw.create_entity('CWPermission', name=pname, label=plabel,
+                                   require_group=self,
+                                   reverse_require_permission=entity)
+
 
 class CWUser(AnyEntity):
     __regid__ = 'CWUser'
@@ -123,6 +139,18 @@
             return False
     owns = cached(owns, keyarg=1)
 
+    def has_permission(self, pname, contexteid=None):
+        rql = 'Any P WHERE P is CWPermission, U eid %(u)s, U in_group G, '\
+              'P name %(pname)s, P require_group G'
+        kwargs = {'pname': pname, 'u': self.eid}
+        if contexteid is not None:
+            rql += ', X require_permission P, X eid %(x)s'
+            kwargs['x'] = contexteid
+        try:
+            return self._cw.execute(rql, kwargs)
+        except Unauthorized:
+            return False
+
     # presentation utilities ##################################################
 
     def name(self):