[repo, undo] Finish repository-side implementation of the undo feature (closes #893940)
1) Changes API for undo_transaction in order to raise an exception:
the previous API returned a sequence of error, the user of the API
needed to be careful to check explicitly. We change this for it to
raise an UndoException with the list of errors as an attribute.
2) The server-side support for undoing update actions is finished
3) The configuration for `undo-support` is now a simple boolean
Beware of the costs, both in DB space and in number of requests
on the RDBMS backend, once this feture is activated.
4) Adds a txuuid param/attribute to the existing NoSuchTransaction
exception.
# 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.
#
# CubicWeb 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/>.
"""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.
"""
__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):
# Used by CubicWebException
msg = _("there is no transaction #%s")
def __init__(self, txuuid):
super(RepositoryError, self).__init__(txuuid)
self.txuuid = txuuid
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}).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')