"""Core hooks: check for data integrity according to the instance'schema
validity
: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.selectors import entity_implements
from cubicweb.common.uilib import soup2xhtml
from cubicweb.server import hook
from cubicweb.server.pool import LateOperation, PreCommitOperation
# special relations that don't have to be checked for integrity, usually
# because they are handled internally by hooks (so we trust ourselves)
DONT_CHECK_RTYPES_ON_ADD = set(('owned_by', 'created_by',
'is', 'is_instance_of',
'wf_info_for', 'from_state', 'to_state'))
DONT_CHECK_RTYPES_ON_DEL = set(('is', 'is_instance_of',
'wf_info_for', 'from_state', 'to_state'))
class _CheckRequiredRelationOperation(hook.LateOperation):
"""checking relation cardinality has to be done after commit in
case the relation is being replaced
"""
eid, rtype = None, None
def precommit_event(self):
# recheck pending eids
if self.session.deleted_in_transaction(self.eid):
return
if self.session.unsafe_execute(*self._rql()).rowcount < 1:
etype = self.session.describe(self.eid)[0]
_ = self.session._
msg = _('at least one relation %(rtype)s is required on %(etype)s (%(eid)s)')
msg %= {'rtype': _(self.rtype), 'etype': _(etype), 'eid': self.eid}
raise ValidationError(self.eid, {self.rtype: msg})
def commit_event(self):
pass
def _rql(self):
raise NotImplementedError()
class _CheckSRelationOp(_CheckRequiredRelationOperation):
"""check required subject relation"""
def _rql(self):
return 'Any O WHERE S eid %%(x)s, S %s O' % self.rtype, {'x': self.eid}, 'x'
class _CheckORelationOp(_CheckRequiredRelationOperation):
"""check required object relation"""
def _rql(self):
return 'Any S WHERE O eid %%(x)s, S %s O' % self.rtype, {'x': self.eid}, 'x'
class IntegrityHook(hook.Hook):
__abstract__ = True
category = 'integrity'
class CheckCardinalityHook(IntegrityHook):
"""check cardinalities are satisfied"""
__id__ = 'checkcard'
events = ('after_add_entity', 'before_delete_relation')
def __call__(self):
getattr(self, self.event)()
def checkrel_if_necessary(self, opcls, rtype, eid):
"""check an equivalent operation has not already been added"""
for op in self._cw.pending_operations:
if isinstance(op, opcls) and op.rtype == rtype and op.eid == eid:
break
else:
opcls(self._cw, rtype=rtype, eid=eid)
def after_add_entity(self):
eid = self.entity.eid
eschema = self.entity.e_schema
for rschema, targetschemas, x in eschema.relation_definitions():
# skip automatically handled relations
if rschema.type in DONT_CHECK_RTYPES_ON_ADD:
continue
if x == 'subject':
subjtype = eschema
objtype = targetschemas[0].type
cardindex = 0
opcls = _CheckSRelationOp
else:
subjtype = targetschemas[0].type
objtype = eschema
cardindex = 1
opcls = _CheckORelationOp
card = rschema.rproperty(subjtype, objtype, 'cardinality')
if card[cardindex] in '1+':
self.checkrel_if_necessary(opcls, rschema.type, eid)
def before_delete_relation(self):
rtype = self.rtype
if rtype in DONT_CHECK_RTYPES_ON_DEL:
return
session = self._cw
eidfrom, eidto = self.eidfrom, self.eidto
card = session.schema_rproperty(rtype, eidfrom, eidto, 'cardinality')
pendingrdefs = session.transaction_data.get('pendingrdefs', ())
if (session.describe(eidfrom)[0], rtype, session.describe(eidto)[0]) in pendingrdefs:
return
if card[0] in '1+' and not session.deleted_in_transaction(eidfrom):
self.checkrel_if_necessary(_CheckSRelationOp, rtype, eidfrom)
if card[1] in '1+' and not session.deleted_in_transaction(eidto):
self.checkrel_if_necessary(_CheckORelationOp, rtype, eidto)
class _CheckConstraintsOp(hook.LateOperation):
"""check a new relation satisfy its constraints
"""
def precommit_event(self):
eidfrom, rtype, eidto = self.rdef
# first check related entities have not been deleted in the same
# transaction
if self.session.deleted_in_transaction(eidfrom):
return
if self.session.deleted_in_transaction(eidto):
return
for constraint in self.constraints:
try:
constraint.repo_check(self.session, eidfrom, rtype, eidto)
except NotImplementedError:
self.critical('can\'t check constraint %s, not supported',
constraint)
def commit_event(self):
pass
class CheckConstraintHook(IntegrityHook):
"""check the relation satisfy its constraints
this is delayed to a precommit time operation since other relation which
will make constraint satisfied may be added later.
"""
__id__ = 'checkconstraint'
events = ('after_add_relation',)
def __call__(self):
constraints = self._cw.schema_rproperty(self.rtype, self.eidfrom, self.eidto,
'constraints')
if constraints:
_CheckConstraintsOp(self._cw, constraints=constraints,
rdef=(self.eidfrom, self.rtype, self.eidto))
class CheckUniqueHook(IntegrityHook):
__id__ = 'checkunique'
events = ('before_add_entity', 'before_update_entity')
def __call__(self):
entity = self.entity
eschema = entity.e_schema
for attr in entity.edited_attributes:
val = entity[attr]
if val is None:
continue
if eschema.subject_relation(attr).is_final() and \
eschema.has_unique_values(attr):
rql = '%s X WHERE X %s %%(val)s' % (entity.e_schema, attr)
rset = self._cw.unsafe_execute(rql, {'val': val})
if rset and rset[0][0] != entity.eid:
msg = self._cw._('the value "%s" is already used, use another one')
raise ValidationError(entity.eid, {attr: msg % val})
class _DelayedDeleteOp(hook.Operation):
"""delete the object of composite relation except if the relation
has actually been redirected to another composite
"""
def precommit_event(self):
session = self.session
# don't do anything if the entity is being created or deleted
if not (session.deleted_in_transaction(self.eid) or
session.added_in_transaction(self.eid)):
etype = session.describe(self.eid)[0]
session.unsafe_execute('DELETE %s X WHERE X eid %%(x)s, NOT %s'
% (etype, self.relation),
{'x': self.eid}, 'x')
class DeleteCompositeOrphanHook(IntegrityHook):
"""delete the composed of a composite relation when this relation is deleted
"""
__id__ = 'deletecomposite'
events = ('before_delete_relation',)
def __call__(self):
composite = self._cw.schema_rproperty(self.rtype, self.eidfrom, self.eidto,
'composite')
if composite == 'subject':
_DelayedDeleteOp(self._cw, eid=self.eidto,
relation='Y %s X' % self.rtype)
elif composite == 'object':
_DelayedDeleteOp(self._cw, eid=self.eidfrom,
relation='X %s Y' % self.rtype)
class DontRemoveOwnersGroupHook(IntegrityHook):
"""delete the composed of a composite relation when this relation is deleted
"""
__id__ = 'checkownersgroup'
__select__ = IntegrityHook.__select__ & entity_implements('CWGroup')
events = ('before_delete_entity', 'before_update_entity')
def __call__(self):
if self.event == 'before_delete_entity' and self.entity.name == 'owners':
raise ValidationError(self.entity.eid, {None: self._cw._('can\'t be deleted')})
elif self.event == 'before_update_entity' and 'name' in self.entity.edited_attributes:
newname = self.entity.pop('name')
oldname = self.entity.name
if oldname == 'owners' and newname != oldname:
raise ValidationError(self.entity.eid, {'name': self._cw._('can\'t be changed')})
self.entity['name'] = newname
class TidyHtmlFields(IntegrityHook):
"""tidy HTML in rich text strings"""
__id__ = 'htmltidy'
events = ('before_add_entity', 'before_update_entity')
def __call__(self):
entity = self.entity
metaattrs = entity.e_schema.meta_attributes()
for metaattr, (metadata, attr) in metaattrs.iteritems():
if metadata == 'format' and attr in entity.edited_attributes:
try:
value = entity[attr]
except KeyError:
continue # no text to tidy
if isinstance(value, unicode): # filter out None and Binary
if getattr(entity, str(metaattr)) == 'text/html':
entity[attr] = soup2xhtml(value, self._cw.encoding)
class StripCWUserLoginHook(IntegrityHook):
"""ensure user logins are stripped"""
__id__ = 'stripuserlogin'
__select__ = IntegrityHook.__select__ & entity_implements('CWUser')
events = ('before_add_entity', 'before_update_entity',)
def __call__(self):
user = self.entity
if 'login' in user.edited_attributes and user.login:
entity.login = entity.login.strip()