--- /dev/null	Thu Jan 01 00:00:00 1970 +0000
+++ b/hooks/workflow.py	Fri Aug 14 09:26:41 2009 +0200
@@ -0,0 +1,106 @@
+"""Core hooks: workflow related hooks
+
+:organization: Logilab
+:copyright: 2001-2009 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"
+
+from cubicweb import ValidationError
+from cubicweb.interfaces import IWorkflowable
+from cubicweb.selectors import entity_implements
+from cubicweb.server.hook import Hook, match_rtype
+from cubicweb.server.pool import PreCommitOperation
+from cubicweb.server.hookhelper import previous_state
+
+
+def relation_deleted(session, eidfrom, rtype, eidto):
+    session.transaction_data.setdefault('pendingrelations', []).append(
+        (eidfrom, rtype, eidto))
+
+
+class _SetInitialStateOp(PreCommitOperation):
+    """make initial state be a default state"""
+
+    def precommit_event(self):
+        session = self.session
+        entity = self.entity
+        # if there is an initial state and the entity's state is not set,
+        # use the initial state as a default state
+        pendingeids = session.transaction_data.get('pendingeids', ())
+        if not entity.eid in pendingeids and not entity.in_state:
+            rset = session.execute('Any S WHERE ET initial_state S, ET name %(name)s',
+                                   {'name': entity.id})
+            if rset:
+                session.add_relation(entity.eid, 'in_state', rset[0][0])
+
+
+class SetInitialStateHook(Hook):
+    __id__ = 'wfsetinitial'
+    __select__ = Hook.__select__ & entity_implements(IWorkflowable)
+    category = 'worfklow'
+    events = ('after_add_entity',)
+
+    def __call__(self):
+        _SetInitialStateOp(self.cw_req, entity=self.entity)
+
+
+class PrepareStateChangeHook(Hook):
+    """record previous state information"""
+    __id__ = 'cwdelstate'
+    __select__ = Hook.__select__ & match_rtype('in_state')
+    category = 'worfklow'
+    events = ('before_delete_relation',)
+
+    def __call__(self):
+        self.cw_req.transaction_data.setdefault('pendingrelations', []).append(
+            (self.eidfrom, self.rtype, self.eidto))
+
+
+class FireTransitionHook(PrepareStateChangeHook):
+    """check the transition is allowed and record transition information"""
+    __id__ = 'wffiretransition'
+    events = ('before_add_relation',)
+
+    def __call__(self):
+        session = self.cw_req
+        eidfrom = self.eidfrom
+        eidto = self.eidto
+        state = previous_state(session, eidfrom)
+        etype = session.describe(eidfrom)[0]
+        if not (session.is_super_session or 'managers' in session.user.groups):
+            if not state is None:
+                entity = session.entity_from_eid(eidfrom)
+                # we should find at least one transition going to this state
+                try:
+                    iter(state.transitions(entity, eidto)).next()
+                except StopIteration:
+                    msg = session._('transition is not allowed')
+                    raise ValidationError(eidfrom, {'in_state': msg})
+            else:
+                # not a transition
+                # check state is initial state if the workflow defines one
+                isrset = session.unsafe_execute('Any S WHERE ET initial_state S, ET name %(etype)s',
+                                                {'etype': etype})
+                if isrset and not eidto == isrset[0][0]:
+                    msg = session._('not the initial state for this entity')
+                    raise ValidationError(eidfrom, {'in_state': msg})
+        eschema = session.repo.schema[etype]
+        if not 'wf_info_for' in eschema.object_relations():
+            # workflow history not activated for this entity type
+            return
+        rql = 'INSERT TrInfo T: T wf_info_for E, T to_state DS, T comment %(comment)s'
+        args = {'comment': session.get_shared_data('trcomment', None, pop=True),
+                'e': eidfrom, 'ds': eidto}
+        cformat = session.get_shared_data('trcommentformat', None, pop=True)
+        if cformat is not None:
+            args['comment_format'] = cformat
+            rql += ', T comment_format %(comment_format)s'
+        restriction = ['DS eid %(ds)s, E eid %(e)s']
+        if not state is None: # not a transition
+            rql += ', T from_state FS'
+            restriction.append('FS eid %(fs)s')
+            args['fs'] = state.eid
+        rql = '%s WHERE %s' % (rql, ', '.join(restriction))
+        session.unsafe_execute(rql, args, 'e')