"""Hooks management
Hooks are called before / after any individual update of entities / relations
in the repository.
Here is the prototype of the different hooks:
* filtered on the entity's type:
before_add_entity (session, entity)
after_add_entity (session, entity)
before_update_entity (session, entity)
after_update_entity (session, entity)
before_delete_entity (session, eid)
after_delete_entity (session, eid)
* filtered on the relation's type:
before_add_relation (session, fromeid, rtype, toeid)
after_add_relation (session, fromeid, rtype, toeid)
before_delete_relation (session, fromeid, rtype, toeid)
after_delete_relation (session, fromeid, rtype, toeid)
: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"
ENTITIES_HOOKS = ('before_add_entity', 'after_add_entity',
'before_update_entity', 'after_update_entity',
'before_delete_entity', 'after_delete_entity')
RELATIONS_HOOKS = ('before_add_relation', 'after_add_relation' ,
'before_delete_relation','after_delete_relation')
SYSTEM_HOOKS = ('server_backup', 'server_restore',
'server_startup', 'server_shutdown',
'session_open', 'session_close')
ALL_HOOKS = frozenset(ENTITIES_HOOKS + RELATIONS_HOOKS + SYSTEM_HOOKS)
class HooksManager(object):
"""handle hooks registration and calls
"""
verification_hooks_activated = True
def __init__(self, schema):
self.set_schema(schema)
def set_schema(self, schema):
self._hooks = {}
self.schema = schema
self._init_hooks(schema)
def register_hooks(self, hooks):
"""register a dictionary of hooks :
{'event': {'entity or relation type': [callbacks list]}}
"""
for event, subevents in hooks.items():
for subevent, callbacks in subevents.items():
for callback in callbacks:
self.register_hook(callback, event, subevent)
def register_hook(self, function, event, etype=''):
"""register a function to call when <event> occurs
<etype> is an entity/relation type or an empty string.
If etype is the empty string, the function will be called at each event,
else the function will be called only when event occurs on an entity or
relation of the given type.
"""
assert event in ALL_HOOKS, '%r NOT IN %r' % (event, ALL_HOOKS)
assert (not event in SYSTEM_HOOKS or not etype), (event, etype)
etype = etype or ''
try:
self._hooks[event][etype].append(function)
self.debug('registered hook %s on %s (%s)', event, etype or 'any',
function.func_name)
except KeyError:
self.error('can\'t register hook %s on %s (%s)',
event, etype or 'any', function.func_name)
def unregister_hook(self, function_or_cls, event=None, etype=''):
"""unregister a function to call when <event> occurs, or a Hook subclass.
In the later case, event/type information are extracted from the given
class.
"""
if isinstance(function_or_cls, type) and issubclass(function_or_cls, Hook):
for event, ertype in function_or_cls.register_to():
for hook in self._hooks[event][ertype]:
if getattr(hook, 'im_self', None).__class__ is function_or_cls:
self._hooks[event][ertype].remove(hook)
self.info('unregister hook %s on %s (%s)', event, etype,
function_or_cls.__name__)
break
else:
self.warning("can't unregister hook %s on %s (%s), not found",
event, etype, function_or_cls.__name__)
else:
assert event in ALL_HOOKS, event
etype = etype or ''
self.info('unregister hook %s on %s (%s)', event, etype,
function_or_cls.func_name)
self._hooks[event][etype].remove(function_or_cls)
def call_hooks(self, __event, __type='', *args, **kwargs):
"""call hook matching event and optional type"""
if __type:
self.info('calling hooks for event %s (%s)', __event, __type)
else:
self.info('calling hooks for event %s', __event)
# call generic hooks first
for hook in self._hooks[__event]['']:
#print '[generic]', hook.__name__
hook(*args, **kwargs)
if __type:
for hook in self._hooks[__event][__type]:
#print '[%s]'%__type, hook.__name__
hook(*args, **kwargs)
def _init_hooks(self, schema):
"""initialize the hooks map"""
for hook_event in ENTITIES_HOOKS:
self._hooks[hook_event] = {'': []}
for etype in schema.entities():
self._hooks[hook_event][etype] = []
for hook_event in RELATIONS_HOOKS:
self._hooks[hook_event] = {'': []}
for r_type in schema.relations():
self._hooks[hook_event][r_type] = []
for hook_event in SYSTEM_HOOKS:
self._hooks[hook_event] = {'': []}
def register_system_hooks(self, config):
"""register system hooks according to the configuration"""
self.info('register core hooks')
from cubicweb.server.hooks import _register_metadata_hooks, _register_wf_hooks
_register_metadata_hooks(self)
self.info('register workflow hooks')
_register_wf_hooks(self)
if config.core_hooks:
from cubicweb.server.hooks import _register_core_hooks
_register_core_hooks(self)
if config.schema_hooks:
from cubicweb.server.schemahooks import _register_schema_hooks
self.info('register schema hooks')
_register_schema_hooks(self)
if config.usergroup_hooks:
from cubicweb.server.hooks import _register_usergroup_hooks
from cubicweb.server.hooks import _register_eproperty_hooks
self.info('register user/group hooks')
_register_usergroup_hooks(self)
_register_eproperty_hooks(self)
if config.security_hooks:
from cubicweb.server.securityhooks import register_security_hooks
self.info('register security hooks')
register_security_hooks(self)
if not self.verification_hooks_activated:
self.deactivate_verification_hooks()
def deactivate_verification_hooks(self):
from cubicweb.server.hooks import (cardinalitycheck_after_add_entity,
cardinalitycheck_before_del_relation,
cstrcheck_after_add_relation,
uniquecstrcheck_before_modification)
self.warning('deactivating verification hooks')
self.verification_hooks_activated = False
self.unregister_hook(cardinalitycheck_after_add_entity, 'after_add_entity', '')
self.unregister_hook(cardinalitycheck_before_del_relation, 'before_delete_relation', '')
self.unregister_hook(cstrcheck_after_add_relation, 'after_add_relation', '')
self.unregister_hook(uniquecstrcheck_before_modification, 'before_add_entity', '')
self.unregister_hook(uniquecstrcheck_before_modification, 'before_update_entity', '')
# self.unregister_hook(tidy_html_fields('before_add_entity'), 'before_add_entity', '')
# self.unregister_hook(tidy_html_fields('before_update_entity'), 'before_update_entity', '')
def reactivate_verification_hooks(self):
from cubicweb.server.hooks import (cardinalitycheck_after_add_entity,
cardinalitycheck_before_del_relation,
cstrcheck_after_add_relation,
uniquecstrcheck_before_modification)
self.warning('reactivating verification hooks')
self.verification_hooks_activated = True
self.register_hook(cardinalitycheck_after_add_entity, 'after_add_entity', '')
self.register_hook(cardinalitycheck_before_del_relation, 'before_delete_relation', '')
self.register_hook(cstrcheck_after_add_relation, 'after_add_relation', '')
self.register_hook(uniquecstrcheck_before_modification, 'before_add_entity', '')
self.register_hook(uniquecstrcheck_before_modification, 'before_update_entity', '')
# self.register_hook(tidy_html_fields('before_add_entity'), 'before_add_entity', '')
# self.register_hook(tidy_html_fields('before_update_entity'), 'before_update_entity', '')
from cubicweb.selectors import yes
from cubicweb.appobject import AppObject
class autoid(type):
"""metaclass to create an unique 'id' attribute on the class using it"""
# XXX is this metaclass really necessary ?
def __new__(mcs, name, bases, classdict):
cls = super(autoid, mcs).__new__(mcs, name, bases, classdict)
cls.id = str(id(cls))
return cls
class Hook(AppObject):
__metaclass__ = autoid
__registry__ = 'hooks'
__select__ = yes()
# set this in derivated classes
events = None
accepts = None
enabled = True
def __init__(self, event=None):
super(Hook, self).__init__()
self.event = event
@classmethod
def registered(cls, vreg):
super(Hook, cls).registered(vreg)
return cls()
@classmethod
def register_to(cls):
if not cls.enabled:
cls.warning('%s hook has been disabled', cls)
return
done = set()
assert isinstance(cls.events, (tuple, list)), \
'%s: events is expected to be a tuple, not %s' % (
cls, type(cls.events))
for event in cls.events:
if event in SYSTEM_HOOKS:
assert not cls.accepts or cls.accepts == ('Any',), \
'%s doesnt make sense on %s' % (cls.accepts, event)
cls.accepts = ('Any',)
for ertype in cls.accepts:
if (event, ertype) in done:
continue
yield event, ertype
done.add((event, ertype))
try:
eschema = cls.schema.eschema(ertype)
except KeyError:
# relation schema
pass
else:
for eetype in eschema.specialized_by():
if (event, eetype) in done:
continue
yield event, str(eetype)
done.add((event, eetype))
def make_callback(self, event):
if len(self.events) == 1:
return self.call
return self.__class__(event=event).call
def call(self):
raise NotImplementedError
class SystemHook(Hook):
accepts = ()
from logging import getLogger
from cubicweb import set_log_methods
set_log_methods(HooksManager, getLogger('cubicweb.hooksmanager'))
set_log_methods(Hook, getLogger('cubicweb.hooks'))
# base classes for relation propagation ########################################
from cubicweb.server.pool import PreCommitOperation
class PropagateSubjectRelationHook(Hook):
"""propagate permissions and nosy list when new entity are added"""
events = ('after_add_relation',)
# to set in concrete class
rtype = None
subject_relations = None
object_relations = None
accepts = None # subject_relations + object_relations
def call(self, session, fromeid, rtype, toeid):
for eid in (fromeid, toeid):
etype = session.describe(eid)[0]
if self.rtype not in self.schema.eschema(etype).subjrels:
return
if rtype in self.subject_relations:
meid, seid = fromeid, toeid
else:
assert rtype in self.object_relations
meid, seid = toeid, fromeid
session.unsafe_execute(
'SET E %s P WHERE X %s P, X eid %%(x)s, E eid %%(e)s, NOT E %s P'\
% (self.rtype, self.rtype, self.rtype),
{'x': meid, 'e': seid}, ('x', 'e'))
class PropagateSubjectRelationAddHook(Hook):
"""propagate on existing entities when a permission or nosy list is added"""
events = ('after_add_relation',)
# to set in concrete class
rtype = None
subject_relations = None
object_relations = None
accepts = None # (self.rtype,)
def call(self, session, fromeid, rtype, toeid):
eschema = self.schema.eschema(session.describe(fromeid)[0])
execute = session.unsafe_execute
for rel in self.subject_relations:
if rel in eschema.subjrels:
execute('SET R %s P WHERE X eid %%(x)s, P eid %%(p)s, '
'X %s R, NOT R %s P' % (rtype, rel, rtype),
{'x': fromeid, 'p': toeid}, 'x')
for rel in self.object_relations:
if rel in eschema.objrels:
execute('SET R %s P WHERE X eid %%(x)s, P eid %%(p)s, '
'R %s X, NOT R %s P' % (rtype, rel, rtype),
{'x': fromeid, 'p': toeid}, 'x')
class PropagateSubjectRelationDelHook(Hook):
"""propagate on existing entities when a permission is deleted"""
events = ('after_delete_relation',)
# to set in concrete class
rtype = None
subject_relations = None
object_relations = None
accepts = None # (self.rtype,)
def call(self, session, fromeid, rtype, toeid):
eschema = self.schema.eschema(session.describe(fromeid)[0])
execute = session.unsafe_execute
for rel in self.subject_relations:
if rel in eschema.subjrels:
execute('DELETE R %s P WHERE X eid %%(x)s, P eid %%(p)s, '
'X %s R' % (rtype, rel),
{'x': fromeid, 'p': toeid}, 'x')
for rel in self.object_relations:
if rel in eschema.objrels:
execute('DELETE R %s P WHERE X eid %%(x)s, P eid %%(p)s, '
'R %s X' % (rtype, rel),
{'x': fromeid, 'p': toeid}, 'x')