--- /dev/null	Thu Jan 01 00:00:00 1970 +0000
+++ b/transaction.py	Mon Mar 01 11:26:14 2010 +0100
@@ -0,0 +1,96 @@
+"""undoable transaction objects.
+
+
+This module is in the cubicweb package and not in cubicweb.server because those
+objects should be accessible to client through pyro, where the cubicweb.server
+package may not be installed.
+
+:organization: Logilab
+:copyright: 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"
+_ = unicode
+
+from cubicweb import RepositoryError
+
+
+ACTION_LABELS = {
+    'C': _('entity creation'),
+    'U': _('entity update'),
+    'D': _('entity deletion'),
+    'A': _('relation add'),
+    'R': _('relation removal'),
+    }
+
+
+class NoSuchTransaction(RepositoryError):
+    pass
+
+
+class Transaction(object):
+    """an undoable transaction"""
+
+    def __init__(self, uuid, time, ueid):
+        self.uuid = uuid
+        self.datetime = time
+        self.user_eid = ueid
+        # should be set by the dbapi connection
+        self.req = None
+
+    def __repr__(self):
+        return '<Transaction %s by %s on %s>' % (
+            self.uuid, self.user_eid, self.datetime)
+
+    def user(self):
+        """return the user entity which has done the transaction,
+        none if not found.
+        """
+        return self.req.execute('Any X WHERE X eid %(x)s',
+                                {'x': self.user_eid}, 'x').get_entity(0, 0)
+
+    def actions_list(self, public=True):
+        """return an ordered list of action effectued during that transaction
+
+        if public is true, return only 'public' action, eg not ones triggered
+        under the cover by hooks.
+        """
+        return self.req.cnx.transaction_actions(self.uuid, public)
+
+
+class AbstractAction(object):
+    def __init__(self, action, public, order):
+        self.action = action
+        self.public = public
+        self.order = order
+
+    @property
+    def label(self):
+        return ACTION_LABELS[self.action]
+
+
+class EntityAction(AbstractAction):
+    def __init__(self, action, public, order, etype, eid, changes):
+        AbstractAction.__init__(self, action, public, order)
+        self.etype = etype
+        self.eid = eid
+        self.changes = changes
+
+    def __repr__(self):
+        return '<%s: %s %s (%s)>' % (
+            self.label, self.eid, self.changes,
+            self.public and 'dbapi' or 'hook')
+
+
+class RelationAction(AbstractAction):
+    def __init__(self, action, public, order, rtype, eidfrom, eidto):
+        AbstractAction.__init__(self, action, public, order)
+        self.rtype = rtype
+        self.eid_from = eidfrom
+        self.eid_to = eidto
+
+    def __repr__(self):
+        return '<%s: %s %s %s (%s)>' % (
+            self.label, self.eid_from, self.rtype, self.eid_to,
+            self.public and 'dbapi' or 'hook')