[entities] skip_copy_for should be considered for object relations too (closes #1857474)
# copyright 2003-2011 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/>.
"""Base class for entity objects manipulated in clients"""
__docformat__ = "restructuredtext en"
from warnings import warn
from logilab.common import interface
from logilab.common.decorators import cached
from logilab.common.deprecation import deprecated
from logilab.mtconverter import TransformData, TransformError, xml_escape
from rql.utils import rqlvar_maker
from cubicweb import Unauthorized, typed_eid, neg_role
from cubicweb.rset import ResultSet
from cubicweb.selectors import yes
from cubicweb.appobject import AppObject
from cubicweb.req import _check_cw_unsafe
from cubicweb.schema import RQLVocabularyConstraint, RQLConstraint
from cubicweb.rqlrewrite import RQLRewriter
from cubicweb.uilib import printable_value, soup2xhtml
from cubicweb.mixins import MI_REL_TRIGGERS
from cubicweb.mttransforms import ENGINE
_marker = object()
def greater_card(rschema, subjtypes, objtypes, index):
for subjtype in subjtypes:
for objtype in objtypes:
card = rschema.rdef(subjtype, objtype).cardinality[index]
if card in '+*':
return card
return '1'
def can_use_rest_path(value):
"""return True if value can be used at the end of a Rest URL path"""
if value is None:
return False
value = unicode(value)
# the check for ?, /, & are to prevent problems when running
# behind Apache mod_proxy
if value == u'' or u'?' in value or u'/' in value or u'&' in value:
return False
return True
def remove_ambiguous_rels(attr_set, subjtypes, schema):
'''remove from `attr_set` the relations of entity types `subjtypes` that have
different entity type sets as target'''
for attr in attr_set.copy():
rschema = schema.rschema(attr)
if rschema.final:
continue
ttypes = None
for subjtype in subjtypes:
cur_ttypes = rschema.objects(subjtype)
if ttypes is None:
ttypes = cur_ttypes
elif cur_ttypes != ttypes:
attr_set.remove(attr)
break
class Entity(AppObject):
"""an entity instance has e_schema automagically set on
the class and instances has access to their issuing cursor.
A property is set for each attribute and relation on each entity's type
class. Becare that among attributes, 'eid' is *NEITHER* stored in the
dict containment (which acts as a cache for other attributes dynamically
fetched)
:type e_schema: `cubicweb.schema.EntitySchema`
:ivar e_schema: the entity's schema
:type rest_var: str
:cvar rest_var: indicates which attribute should be used to build REST urls
If None is specified, the first non-meta attribute will
be used
:type cw_skip_copy_for: list
:cvar cw_skip_copy_for: a list of couples (rtype, role) for each relation
that should be skipped when copying
this kind of entity. Note that some relations such
as composite relations or relations that have '?1' as object
cardinality are always skipped.
"""
__registry__ = 'etypes'
__select__ = yes()
# class attributes that must be set in class definition
rest_attr = None
fetch_attrs = None
skip_copy_for = () # bw compat (< 3.14), use cw_skip_copy_for instead
cw_skip_copy_for = [('in_state', 'subject')]
# class attributes set automatically at registration time
e_schema = None
@classmethod
def __initialize__(cls, schema):
"""initialize a specific entity class by adding descriptors to access
entity type's attributes and relations
"""
etype = cls.__regid__
assert etype != 'Any', etype
cls.e_schema = eschema = schema.eschema(etype)
for rschema, _ in eschema.attribute_definitions():
if rschema.type == 'eid':
continue
setattr(cls, rschema.type, Attribute(rschema.type))
mixins = []
for rschema, _, role in eschema.relation_definitions():
if (rschema, role) in MI_REL_TRIGGERS:
mixin = MI_REL_TRIGGERS[(rschema, role)]
if not (issubclass(cls, mixin) or mixin in mixins): # already mixed ?
mixins.append(mixin)
for iface in getattr(mixin, '__implements__', ()):
if not interface.implements(cls, iface):
interface.extend(cls, iface)
if role == 'subject':
attr = rschema.type
else:
attr = 'reverse_%s' % rschema.type
setattr(cls, attr, Relation(rschema, role))
if mixins:
# see etype class instantation in cwvreg.ETypeRegistry.etype_class method:
# due to class dumping, cls is the generated top level class with actual
# user class as (only) parent. Since we want to be able to override mixins
# method from this user class, we have to take care to insert mixins after that
# class
#
# note that we don't plug mixins as user class parent since it causes pb
# with some cases of entity classes inheritance.
mixins.insert(0, cls.__bases__[0])
mixins += cls.__bases__[1:]
cls.__bases__ = tuple(mixins)
cls.info('plugged %s mixins on %s', mixins, cls)
fetch_attrs = ('modification_date',)
@classmethod
def fetch_order(cls, attr, var):
"""class method used to control sort order when multiple entities of
this type are fetched
"""
return cls.fetch_unrelated_order(attr, var)
@classmethod
def fetch_unrelated_order(cls, attr, var):
"""class method used to control sort order when multiple entities of
this type are fetched to use in edition (eg propose them to create a
new relation on an edited entity).
"""
if attr == 'modification_date':
return '%s DESC' % var
return None
@classmethod
def fetch_rql(cls, user, restriction=None, fetchattrs=None, mainvar='X',
settype=True, ordermethod='fetch_order'):
"""return a rql to fetch all entities of the class type"""
# XXX update api and implementation to AST manipulation (see unrelated rql)
restrictions = restriction or []
if settype:
restrictions.append('%s is %s' % (mainvar, cls.__regid__))
if fetchattrs is None:
fetchattrs = cls.fetch_attrs
selection = [mainvar]
orderby = []
# start from 26 to avoid possible conflicts with X
# XXX not enough to be sure it'll be no conflicts
varmaker = rqlvar_maker(index=26)
cls._fetch_restrictions(mainvar, varmaker, fetchattrs, selection,
orderby, restrictions, user, ordermethod)
rql = 'Any %s' % ','.join(selection)
if orderby:
rql += ' ORDERBY %s' % ','.join(orderby)
rql += ' WHERE %s' % ', '.join(restrictions)
return rql
@classmethod
def _fetch_restrictions(cls, mainvar, varmaker, fetchattrs,
selection, orderby, restrictions, user,
ordermethod='fetch_order', visited=None):
eschema = cls.e_schema
if visited is None:
visited = set((eschema.type,))
elif eschema.type in visited:
# avoid infinite recursion
return
else:
visited.add(eschema.type)
_fetchattrs = []
for attr in fetchattrs:
try:
rschema = eschema.subjrels[attr]
except KeyError:
cls.warning('skipping fetch_attr %s defined in %s (not found in schema)',
attr, cls.__regid__)
continue
rdef = eschema.rdef(attr)
if not user.matching_groups(rdef.get_groups('read')):
continue
var = varmaker.next()
selection.append(var)
restriction = '%s %s %s' % (mainvar, attr, var)
restrictions.append(restriction)
if not rschema.final:
card = rdef.cardinality[0]
if card not in '?1':
cls.warning('bad relation %s specified in fetch attrs for %s',
attr, cls)
selection.pop()
restrictions.pop()
continue
# XXX we need outer join in case the relation is not mandatory
# (card == '?') *or if the entity is being added*, since in
# that case the relation may still be missing. As we miss this
# later information here, systematically add it.
restrictions[-1] += '?'
targettypes = rschema.objects(eschema.type)
# XXX user._cw.vreg iiiirk
etypecls = user._cw.vreg['etypes'].etype_class(targettypes[0])
if len(targettypes) > 1:
# find fetch_attrs common to all destination types
fetchattrs = user._cw.vreg['etypes'].fetch_attrs(targettypes)
remove_ambiguous_rels(fetchattrs, targettypes, user._cw.vreg.schema)
else:
fetchattrs = etypecls.fetch_attrs
etypecls._fetch_restrictions(var, varmaker, fetchattrs,
selection, orderby, restrictions,
user, ordermethod, visited=visited)
if ordermethod is not None:
orderterm = getattr(cls, ordermethod)(attr, var)
if orderterm:
orderby.append(orderterm)
return selection, orderby, restrictions
@classmethod
@cached
def _rest_attr_info(cls):
mainattr, needcheck = 'eid', True
if cls.rest_attr:
mainattr = cls.rest_attr
needcheck = not cls.e_schema.has_unique_values(mainattr)
else:
for rschema in cls.e_schema.subject_relations():
if rschema.final and rschema != 'eid' and cls.e_schema.has_unique_values(rschema):
mainattr = str(rschema)
needcheck = False
break
if mainattr == 'eid':
needcheck = False
return mainattr, needcheck
@classmethod
def cw_instantiate(cls, execute, **kwargs):
"""add a new entity of this given type
Example (in a shell session):
>>> companycls = vreg['etypes'].etype_class(('Company')
>>> personcls = vreg['etypes'].etype_class(('Person')
>>> c = companycls.cw_instantiate(session.execute, name=u'Logilab')
>>> p = personcls.cw_instantiate(session.execute, firstname=u'John', lastname=u'Doe',
... works_for=c)
You can also set relation where the entity has 'object' role by
prefixing the relation by 'reverse_'.
"""
rql = 'INSERT %s X' % cls.__regid__
relations = []
restrictions = set()
pending_relations = []
eschema = cls.e_schema
qargs = {}
for attr, value in kwargs.items():
if attr.startswith('reverse_'):
attr = attr[len('reverse_'):]
role = 'object'
else:
role = 'subject'
assert eschema.has_relation(attr, role), '%s %s not found on %s' % (attr, role, eschema)
rschema = eschema.subjrels[attr] if role == 'subject' else eschema.objrels[attr]
if not rschema.final and isinstance(value, (tuple, list, set, frozenset)):
if len(value) == 1:
value = iter(value).next()
else:
# prepare IN clause
pending_relations.append( (attr, role, value) )
continue
if rschema.final: # attribute
relations.append('X %s %%(%s)s' % (attr, attr))
else:
rvar = attr.upper()
if role == 'object':
relations.append('%s %s X' % (rvar, attr))
else:
relations.append('X %s %s' % (attr, rvar))
restriction = '%s eid %%(%s)s' % (rvar, attr)
if not restriction in restrictions:
restrictions.add(restriction)
if hasattr(value, 'eid'):
value = value.eid
qargs[attr] = value
if relations:
rql = '%s: %s' % (rql, ', '.join(relations))
if restrictions:
rql = '%s WHERE %s' % (rql, ', '.join(restrictions))
created = execute(rql, qargs).get_entity(0, 0)
for attr, role, values in pending_relations:
if role == 'object':
restr = 'Y %s X' % attr
else:
restr = 'X %s Y' % attr
execute('SET %s WHERE X eid %%(x)s, Y eid IN (%s)' % (
restr, ','.join(str(getattr(r, 'eid', r)) for r in values)),
{'x': created.eid}, build_descr=False)
return created
def __init__(self, req, rset=None, row=None, col=0):
AppObject.__init__(self, req, rset=rset, row=row, col=col)
self._cw_related_cache = {}
if rset is not None:
self.eid = rset[row][col]
else:
self.eid = None
self._cw_is_saved = True
self.cw_attr_cache = {}
def __repr__(self):
return '<Entity %s %s %s at %s>' % (
self.e_schema, self.eid, self.cw_attr_cache.keys(), id(self))
def __cmp__(self, other):
raise NotImplementedError('comparison not implemented for %s' % self.__class__)
def __json_encode__(self):
"""custom json dumps hook to dump the entity's eid
which is not part of dict structure itself
"""
dumpable = dict(self)
dumpable['eid'] = self.eid
return dumpable
def cw_adapt_to(self, interface):
"""return an adapter the entity to the given interface name.
return None if it can not be adapted.
"""
try:
cache = self._cw_adapters_cache
except AttributeError:
self._cw_adapters_cache = cache = {}
try:
return cache[interface]
except KeyError:
adapter = self._cw.vreg['adapters'].select_or_none(
interface, self._cw, entity=self)
cache[interface] = adapter
return adapter
def has_eid(self): # XXX cw_has_eid
"""return True if the entity has an attributed eid (False
meaning that the entity has to be created
"""
try:
typed_eid(self.eid)
return True
except (ValueError, TypeError):
return False
def cw_is_saved(self):
"""during entity creation, there is some time during which the entity
has an eid attributed though it's not saved (eg during
'before_add_entity' hooks). You can use this method to ensure the entity
has an eid *and* is saved in its source.
"""
return self.has_eid() and self._cw_is_saved
@cached
def cw_metainformation(self):
res = self._cw.describe(self.eid, asdict=True)
# use 'asource' and not 'source' since this is the actual source,
# while 'source' is the physical source (where it's stored)
res['source'] = self._cw.source_defs()[res.pop('asource')]
return res
def cw_check_perm(self, action):
self.e_schema.check_perm(self._cw, action, eid=self.eid)
def cw_has_perm(self, action):
return self.e_schema.has_perm(self._cw, action, eid=self.eid)
def view(self, __vid, __registry='views', w=None, initargs=None, **kwargs): # XXX cw_view
"""shortcut to apply a view on this entity"""
if initargs is None:
initargs = kwargs
else:
initargs.update(kwargs)
view = self._cw.vreg[__registry].select(__vid, self._cw, rset=self.cw_rset,
row=self.cw_row, col=self.cw_col,
**initargs)
return view.render(row=self.cw_row, col=self.cw_col, w=w, **kwargs)
def absolute_url(self, *args, **kwargs): # XXX cw_url
"""return an absolute url to view this entity"""
# use *args since we don't want first argument to be "anonymous" to
# avoid potential clash with kwargs
if args:
assert len(args) == 1, 'only 0 or 1 non-named-argument expected'
method = args[0]
else:
method = None
# in linksearch mode, we don't want external urls else selecting
# the object for use in the relation is tricky
# XXX search_state is web specific
use_ext_id = False
if 'base_url' not in kwargs and \
getattr(self._cw, 'search_state', ('normal',))[0] == 'normal':
sourcemeta = self.cw_metainformation()['source']
if sourcemeta.get('use-cwuri-as-url'):
return self.cwuri # XXX consider kwargs?
if sourcemeta.get('base-url'):
kwargs['base_url'] = sourcemeta['base-url']
use_ext_id = True
if method in (None, 'view'):
try:
kwargs['_restpath'] = self.rest_path(use_ext_id)
except TypeError:
warn('[3.4] %s: rest_path() now take use_ext_eid argument, '
'please update' % self.__regid__, DeprecationWarning)
kwargs['_restpath'] = self.rest_path()
else:
kwargs['rql'] = 'Any X WHERE X eid %s' % self.eid
return self._cw.build_url(method, **kwargs)
def rest_path(self, use_ext_eid=False): # XXX cw_rest_path
"""returns a REST-like (relative) path for this entity"""
mainattr, needcheck = self._rest_attr_info()
etype = str(self.e_schema)
path = etype.lower()
if mainattr != 'eid':
value = getattr(self, mainattr)
if not can_use_rest_path(value):
mainattr = 'eid'
path += '/eid'
elif needcheck:
# make sure url is not ambiguous
try:
nbresults = self.__unique
except AttributeError:
rql = 'Any COUNT(X) WHERE X is %s, X %s %%(value)s' % (
etype, mainattr)
nbresults = self.__unique = self._cw.execute(rql, {'value' : value})[0][0]
if nbresults != 1: # ambiguity?
mainattr = 'eid'
path += '/eid'
if mainattr == 'eid':
if use_ext_eid:
value = self.cw_metainformation()['extid']
else:
value = self.eid
return '%s/%s' % (path, self._cw.url_quote(value))
def cw_attr_metadata(self, attr, metadata):
"""return a metadata for an attribute (None if unspecified)"""
value = getattr(self, '%s_%s' % (attr, metadata), None)
if value is None and metadata == 'encoding':
value = self._cw.vreg.property_value('ui.encoding')
return value
def printable_value(self, attr, value=_marker, attrtype=None,
format='text/html', displaytime=True): # XXX cw_printable_value
"""return a displayable value (i.e. unicode string) which may contains
html tags
"""
attr = str(attr)
if value is _marker:
value = getattr(self, attr)
if isinstance(value, basestring):
value = value.strip()
if value is None or value == '': # don't use "not", 0 is an acceptable value
return u''
if attrtype is None:
attrtype = self.e_schema.destination(attr)
props = self.e_schema.rdef(attr)
if attrtype == 'String':
# internalinalized *and* formatted string such as schema
# description...
if props.internationalizable:
value = self._cw._(value)
attrformat = self.cw_attr_metadata(attr, 'format')
if attrformat:
return self._cw_mtc_transform(value, attrformat, format,
self._cw.encoding)
elif attrtype == 'Bytes':
attrformat = self.cw_attr_metadata(attr, 'format')
if attrformat:
encoding = self.cw_attr_metadata(attr, 'encoding')
return self._cw_mtc_transform(value.getvalue(), attrformat, format,
encoding)
return u''
value = printable_value(self._cw, attrtype, value, props,
displaytime=displaytime)
if format == 'text/html':
value = xml_escape(value)
return value
def _cw_mtc_transform(self, data, format, target_format, encoding,
_engine=ENGINE):
trdata = TransformData(data, format, encoding, appobject=self)
data = _engine.convert(trdata, target_format).decode()
if format == 'text/html':
data = soup2xhtml(data, self._cw.encoding)
return data
# entity cloning ##########################################################
def copy_relations(self, ceid): # XXX cw_copy_relations
"""copy relations of the object with the given eid on this
object (this method is called on the newly created copy, and
ceid designates the original entity).
By default meta and composite relations are skipped.
Overrides this if you want another behaviour
"""
assert self.has_eid()
execute = self._cw.execute
skip_copy_for = {'subject': set(), 'object': set()}
for rtype in self.skip_copy_for:
skip_copy_for['subject'].add(rtype)
warn('[3.14] skip_copy_for on entity classes (%s) is deprecated, '
'use cw_skip_for instead with list of couples (rtype, role)' % self.__regid__,
DeprecationWarning)
for rtype, role in self.cw_skip_copy_for:
assert role in ('subject', 'object'), role
skip_copy_for[role].add(rtype)
for rschema in self.e_schema.subject_relations():
if rschema.final or rschema.meta:
continue
# skip already defined relations
if getattr(self, rschema.type):
continue
if rschema.type in skip_copy_for['subject']:
continue
# skip composite relation
rdef = self.e_schema.rdef(rschema)
if rdef.composite:
continue
# skip relation with card in ?1 else we either change the copied
# object (inlined relation) or inserting some inconsistency
if rdef.cardinality[1] in '?1':
continue
rql = 'SET X %s V WHERE X eid %%(x)s, Y eid %%(y)s, Y %s V' % (
rschema.type, rschema.type)
execute(rql, {'x': self.eid, 'y': ceid})
self.cw_clear_relation_cache(rschema.type, 'subject')
for rschema in self.e_schema.object_relations():
if rschema.meta:
continue
# skip already defined relations
if self.related(rschema.type, 'object'):
continue
if rschema.type in skip_copy_for['object']:
continue
rdef = self.e_schema.rdef(rschema, 'object')
# skip composite relation
if rdef.composite:
continue
# skip relation with card in ?1 else we either change the copied
# object (inlined relation) or inserting some inconsistency
if rdef.cardinality[0] in '?1':
continue
rql = 'SET V %s X WHERE X eid %%(x)s, Y eid %%(y)s, V %s Y' % (
rschema.type, rschema.type)
execute(rql, {'x': self.eid, 'y': ceid})
self.cw_clear_relation_cache(rschema.type, 'object')
# data fetching methods ###################################################
@cached
def as_rset(self): # XXX .cw_as_rset
"""returns a resultset containing `self` information"""
rset = ResultSet([(self.eid,)], 'Any X WHERE X eid %(x)s',
{'x': self.eid}, [(self.__regid__,)])
rset.req = self._cw
return rset
def _cw_to_complete_relations(self):
"""by default complete final relations to when calling .complete()"""
for rschema in self.e_schema.subject_relations():
if rschema.final:
continue
targets = rschema.objects(self.e_schema)
if rschema.inlined:
matching_groups = self._cw.user.matching_groups
if all(matching_groups(e.get_groups('read')) and
rschema.rdef(self.e_schema, e).get_groups('read')
for e in targets):
yield rschema, 'subject'
def _cw_to_complete_attributes(self, skip_bytes=True, skip_pwd=True):
for rschema, attrschema in self.e_schema.attribute_definitions():
# skip binary data by default
if skip_bytes and attrschema.type == 'Bytes':
continue
attr = rschema.type
if attr == 'eid':
continue
# password retreival is blocked at the repository server level
rdef = rschema.rdef(self.e_schema, attrschema)
if not self._cw.user.matching_groups(rdef.get_groups('read')) \
or (attrschema.type == 'Password' and skip_pwd):
self.cw_attr_cache[attr] = None
continue
yield attr
_cw_completed = False
def complete(self, attributes=None, skip_bytes=True, skip_pwd=True): # XXX cw_complete
"""complete this entity by adding missing attributes (i.e. query the
repository to fill the entity)
:type skip_bytes: bool
:param skip_bytes:
if true, attribute of type Bytes won't be considered
"""
assert self.has_eid()
if self._cw_completed:
return
if attributes is None:
self._cw_completed = True
varmaker = rqlvar_maker()
V = varmaker.next()
rql = ['WHERE %s eid %%(x)s' % V]
selected = []
for attr in (attributes or self._cw_to_complete_attributes(skip_bytes, skip_pwd)):
# if attribute already in entity, nothing to do
if self.cw_attr_cache.has_key(attr):
continue
# case where attribute must be completed, but is not yet in entity
var = varmaker.next()
rql.append('%s %s %s' % (V, attr, var))
selected.append((attr, var))
# +1 since this doen't include the main variable
lastattr = len(selected) + 1
# don't fetch extra relation if attributes specified or of the entity is
# coming from an external source (may lead to error)
if attributes is None and self.cw_metainformation()['source']['uri'] == 'system':
# fetch additional relations (restricted to 0..1 relations)
for rschema, role in self._cw_to_complete_relations():
rtype = rschema.type
if self.cw_relation_cached(rtype, role):
continue
# at this point we suppose that:
# * this is a inlined relation
# * entity (self) is the subject
# * user has read perm on the relation and on the target entity
assert rschema.inlined
assert role == 'subject'
var = varmaker.next()
# keep outer join anyway, we don't want .complete to crash on
# missing mandatory relation (see #1058267)
rql.append('%s %s %s?' % (V, rtype, var))
selected.append(((rtype, role), var))
if selected:
# select V, we need it as the left most selected variable
# if some outer join are included to fetch inlined relations
rql = 'Any %s,%s %s' % (V, ','.join(var for attr, var in selected),
','.join(rql))
try:
rset = self._cw.execute(rql, {'x': self.eid}, build_descr=False)[0]
except IndexError:
raise Exception('unable to fetch attributes for entity with eid %s'
% self.eid)
# handle attributes
for i in xrange(1, lastattr):
self.cw_attr_cache[str(selected[i-1][0])] = rset[i]
# handle relations
for i in xrange(lastattr, len(rset)):
rtype, role = selected[i-1][0]
value = rset[i]
if value is None:
rrset = ResultSet([], rql, {'x': self.eid})
rrset.req = self._cw
else:
rrset = self._cw.eid_rset(value)
self.cw_set_relation_cache(rtype, role, rrset)
def cw_attr_value(self, name):
"""get value for the attribute relation <name>, query the repository
to get the value if necessary.
:type name: str
:param name: name of the attribute to get
"""
try:
return self.cw_attr_cache[name]
except KeyError:
if not self.cw_is_saved():
return None
rql = "Any A WHERE X eid %%(x)s, X %s A" % name
try:
rset = self._cw.execute(rql, {'x': self.eid})
except Unauthorized:
self.cw_attr_cache[name] = value = None
else:
assert rset.rowcount <= 1, (self, rql, rset.rowcount)
try:
self.cw_attr_cache[name] = value = rset.rows[0][0]
except IndexError:
# probably a multisource error
self.critical("can't get value for attribute %s of entity with eid %s",
name, self.eid)
if self.e_schema.destination(name) == 'String':
self.cw_attr_cache[name] = value = self._cw._('unaccessible')
else:
self.cw_attr_cache[name] = value = None
return value
def related(self, rtype, role='subject', limit=None, entities=False): # XXX .cw_related
"""returns a resultset of related entities
:param role: is the role played by 'self' in the relation ('subject' or 'object')
:param limit: resultset's maximum size
:param entities: if True, the entites are returned; if False, a result set is returned
"""
try:
return self._cw_relation_cache(rtype, role, entities, limit)
except KeyError:
pass
if not self.has_eid():
if entities:
return []
return self._cw.empty_rset()
rql = self.cw_related_rql(rtype, role)
rset = self._cw.execute(rql, {'x': self.eid})
self.cw_set_relation_cache(rtype, role, rset)
return self.related(rtype, role, limit, entities)
def cw_related_rql(self, rtype, role='subject', targettypes=None):
rschema = self._cw.vreg.schema[rtype]
if role == 'subject':
restriction = 'E eid %%(x)s, E %s X' % rtype
if targettypes is None:
targettypes = rschema.objects(self.e_schema)
else:
restriction += ', X is IN (%s)' % ','.join(targettypes)
card = greater_card(rschema, (self.e_schema,), targettypes, 0)
else:
restriction = 'E eid %%(x)s, X %s E' % rtype
if targettypes is None:
targettypes = rschema.subjects(self.e_schema)
else:
restriction += ', X is IN (%s)' % ','.join(targettypes)
card = greater_card(rschema, targettypes, (self.e_schema,), 1)
etypecls = self._cw.vreg['etypes'].etype_class(targettypes[0])
if len(targettypes) > 1:
fetchattrs = self._cw.vreg['etypes'].fetch_attrs(targettypes)
# XXX we should fetch ambiguous relation objects too but not
# recurse on them in _fetch_restrictions; it is easier to remove
# them completely for now, as it would require an deeper api rewrite
remove_ambiguous_rels(fetchattrs, targettypes, self._cw.vreg.schema)
else:
fetchattrs = etypecls.fetch_attrs
rql = etypecls.fetch_rql(self._cw.user, [restriction], fetchattrs,
settype=False)
# optimisation: remove ORDERBY if cardinality is 1 or ? (though
# greater_card return 1 for those both cases)
if card == '1':
if ' ORDERBY ' in rql:
rql = '%s WHERE %s' % (rql.split(' ORDERBY ', 1)[0],
rql.split(' WHERE ', 1)[1])
elif not ' ORDERBY ' in rql:
args = rql.split(' WHERE ', 1)
# if modification_date already retreived, we should use it instead
# of adding another variable for sort. This should be be problematic
# but it's actually with sqlserver, see ticket #694445
if 'X modification_date ' in args[1]:
var = args[1].split('X modification_date ', 1)[1].split(',', 1)[0]
args.insert(1, var.strip())
rql = '%s ORDERBY %s DESC WHERE %s' % tuple(args)
else:
rql = '%s ORDERBY Z DESC WHERE X modification_date Z, %s' % \
tuple(args)
return rql
# generic vocabulary methods ##############################################
def cw_unrelated_rql(self, rtype, targettype, role, ordermethod=None,
vocabconstraints=True):
"""build a rql to fetch `targettype` entities unrelated to this entity
using (rtype, role) relation.
Consider relation permissions so that returned entities may be actually
linked by `rtype`.
"""
ordermethod = ordermethod or 'fetch_unrelated_order'
if isinstance(rtype, basestring):
rtype = self._cw.vreg.schema.rschema(rtype)
rdef = rtype.role_rdef(self.e_schema, targettype, role)
rewriter = RQLRewriter(self._cw)
# initialize some variables according to the `role` of `self` in the
# relation:
# * variable for myself (`evar`) and searched entities (`searchvedvar`)
# * entity type of the subject (`subjtype`) and of the object
# (`objtype`) of the relation
if role == 'subject':
evar, searchedvar = 'S', 'O'
subjtype, objtype = self.e_schema, targettype
else:
searchedvar, evar = 'S', 'O'
objtype, subjtype = self.e_schema, targettype
# initialize some variables according to `self` existance
if rdef.role_cardinality(neg_role(role)) in '?1':
# if cardinality in '1?', we want a target entity which isn't
# already linked using this relation
if searchedvar == 'S':
restriction = ['NOT S %s ZZ' % rtype]
else:
restriction = ['NOT ZZ %s O' % rtype]
elif self.has_eid():
# elif we have an eid, we don't want a target entity which is
# already linked to ourself through this relation
restriction = ['NOT S %s O' % rtype]
else:
restriction = []
if self.has_eid():
restriction += ['%s eid %%(x)s' % evar]
args = {'x': self.eid}
if role == 'subject':
sec_check_args = {'fromeid': self.eid}
else:
sec_check_args = {'toeid': self.eid}
existant = None # instead of 'SO', improve perfs
else:
args = {}
sec_check_args = {}
existant = searchedvar
# retreive entity class for targettype to compute base rql
etypecls = self._cw.vreg['etypes'].etype_class(targettype)
rql = etypecls.fetch_rql(self._cw.user, restriction,
mainvar=searchedvar, ordermethod=ordermethod)
select = self._cw.vreg.parse(self._cw, rql, args).children[0]
# insert RQL expressions for schema constraints into the rql syntax tree
if vocabconstraints:
# RQLConstraint is a subclass for RQLVocabularyConstraint, so they
# will be included as well
cstrcls = RQLVocabularyConstraint
else:
cstrcls = RQLConstraint
for cstr in rdef.constraints:
# consider constraint.mainvars to check if constraint apply
if isinstance(cstr, cstrcls) and searchedvar in cstr.mainvars:
if not self.has_eid() and evar in cstr.mainvars:
continue
# compute a varmap suitable to RQLRewriter.rewrite argument
varmap = dict((v, v) for v in 'SO' if v in select.defined_vars
and v in cstr.mainvars)
# rewrite constraint by constraint since we want a AND between
# expressions.
rewriter.rewrite(select, [(varmap, (cstr,))], select.solutions,
args, existant)
# insert security RQL expressions granting the permission to 'add' the
# relation into the rql syntax tree, if necessary
rqlexprs = rdef.get_rqlexprs('add')
if rqlexprs and not rdef.has_perm(self._cw, 'add', **sec_check_args):
# compute a varmap suitable to RQLRewriter.rewrite argument
varmap = dict((v, v) for v in 'SO' if v in select.defined_vars)
# rewrite all expressions at once since we want a OR between them.
rewriter.rewrite(select, [(varmap, rqlexprs)], select.solutions,
args, existant)
# ensure we have an order defined
if not select.orderby:
select.add_sort_var(select.defined_vars[searchedvar])
# we're done, turn the rql syntax tree as a string
rql = select.as_string()
return rql, args
def unrelated(self, rtype, targettype, role='subject', limit=None,
ordermethod=None): # XXX .cw_unrelated
"""return a result set of target type objects that may be related
by a given relation, with self as subject or object
"""
try:
rql, args = self.cw_unrelated_rql(rtype, targettype, role, ordermethod)
except Unauthorized:
return self._cw.empty_rset()
# XXX should be set in unrelated rql when manipulating the AST
if limit is not None:
before, after = rql.split(' WHERE ', 1)
rql = '%s LIMIT %s WHERE %s' % (before, limit, after)
return self._cw.execute(rql, args)
# relations cache handling #################################################
def cw_relation_cached(self, rtype, role):
"""return None if the given relation isn't already cached on the
instance, else the content of the cache (a 2-uple (rset, entities)).
"""
return self._cw_related_cache.get('%s_%s' % (rtype, role))
def _cw_relation_cache(self, rtype, role, entities=True, limit=None):
"""return values for the given relation if it's cached on the instance,
else raise `KeyError`
"""
res = self._cw_related_cache['%s_%s' % (rtype, role)][entities]
if limit is not None and limit < len(res):
if entities:
res = res[:limit]
else:
res = res.limit(limit)
return res
def cw_set_relation_cache(self, rtype, role, rset):
"""set cached values for the given relation"""
if rset:
related = list(rset.entities(0))
rschema = self._cw.vreg.schema.rschema(rtype)
if role == 'subject':
rcard = rschema.rdef(self.e_schema, related[0].e_schema).cardinality[1]
target = 'object'
else:
rcard = rschema.rdef(related[0].e_schema, self.e_schema).cardinality[0]
target = 'subject'
if rcard in '?1':
for rentity in related:
rentity._cw_related_cache['%s_%s' % (rtype, target)] = (
self.as_rset(), (self,))
else:
related = ()
self._cw_related_cache['%s_%s' % (rtype, role)] = (rset, related)
def cw_clear_relation_cache(self, rtype=None, role=None):
"""clear cached values for the given relation or the entire cache if
no relation is given
"""
if rtype is None:
self._cw_related_cache = {}
self._cw_adapters_cache = {}
else:
assert role
self._cw_related_cache.pop('%s_%s' % (rtype, role), None)
def cw_clear_all_caches(self):
"""flush all caches on this entity. Further attributes/relations access
will triggers new database queries to get back values.
If you use custom caches on your entity class (take care to @cached!),
you should override this method to clear them as well.
"""
# clear attributes cache
self._cw_completed = False
self.cw_attr_cache.clear()
# clear relations cache
self.cw_clear_relation_cache()
# rest path unique cache
try:
del self.__unique
except AttributeError:
pass
# raw edition utilities ###################################################
def set_attributes(self, **kwargs): # XXX cw_set_attributes
_check_cw_unsafe(kwargs)
assert kwargs
assert self.cw_is_saved(), "should not call set_attributes while entity "\
"hasn't been saved yet"
relations = ['X %s %%(%s)s' % (key, key) for key in kwargs]
# and now update the database
kwargs['x'] = self.eid
self._cw.execute('SET %s WHERE X eid %%(x)s' % ','.join(relations),
kwargs)
kwargs.pop('x')
# update current local object _after_ the rql query to avoid
# interferences between the query execution itself and the cw_edited /
# skip_security machinery
self.cw_attr_cache.update(kwargs)
def set_relations(self, **kwargs): # XXX cw_set_relations
"""add relations to the given object. To set a relation where this entity
is the object of the relation, use 'reverse_'<relation> as argument name.
Values may be an entity or eid, a list of entities or eids, or None
(meaning that all relations of the given type from or to this object
should be deleted).
"""
# XXX update cache
_check_cw_unsafe(kwargs)
for attr, values in kwargs.iteritems():
if attr.startswith('reverse_'):
restr = 'Y %s X' % attr[len('reverse_'):]
else:
restr = 'X %s Y' % attr
if values is None:
self._cw.execute('DELETE %s WHERE X eid %%(x)s' % restr,
{'x': self.eid})
continue
if not isinstance(values, (tuple, list, set, frozenset)):
values = (values,)
eids = []
for val in values:
try:
eids.append(str(val.eid))
except AttributeError:
try:
eids.append(str(typed_eid(val)))
except (ValueError, TypeError):
raise Exception('expected an Entity or eid, got %s' % val)
self._cw.execute('SET %s WHERE X eid %%(x)s, Y eid IN (%s)' % (
restr, ','.join(eids)), {'x': self.eid})
def cw_delete(self, **kwargs):
assert self.has_eid(), self.eid
self._cw.execute('DELETE %s X WHERE X eid %%(x)s' % self.e_schema,
{'x': self.eid}, **kwargs)
# server side utilities ####################################################
def _cw_clear_local_perm_cache(self, action):
for rqlexpr in self.e_schema.get_rqlexprs(action):
self._cw.local_perm_cache.pop((rqlexpr.eid, (('x', self.eid),)), None)
# deprecated stuff #########################################################
@deprecated('[3.13] use entity.cw_clear_all_caches()')
def clear_all_caches(self):
return self.cw_clear_all_caches()
@deprecated('[3.9] use entity.cw_attr_value(attr)')
def get_value(self, name):
return self.cw_attr_value(name)
@deprecated('[3.9] use entity.cw_delete()')
def delete(self, **kwargs):
return self.cw_delete(**kwargs)
@deprecated('[3.9] use entity.cw_attr_metadata(attr, metadata)')
def attr_metadata(self, attr, metadata):
return self.cw_attr_metadata(attr, metadata)
@deprecated('[3.9] use entity.cw_has_perm(action)')
def has_perm(self, action):
return self.cw_has_perm(action)
@deprecated('[3.9] use entity.cw_set_relation_cache(rtype, role, rset)')
def set_related_cache(self, rtype, role, rset):
self.cw_set_relation_cache(rtype, role, rset)
@deprecated('[3.9] use entity.cw_clear_relation_cache(rtype, role)')
def clear_related_cache(self, rtype=None, role=None):
self.cw_clear_relation_cache(rtype, role)
@deprecated('[3.9] use entity.cw_related_rql(rtype, [role, [targettypes]])')
def related_rql(self, rtype, role='subject', targettypes=None):
return self.cw_related_rql(rtype, role, targettypes)
@property
@deprecated('[3.10] use entity.cw_edited')
def edited_attributes(self):
return self.cw_edited
@property
@deprecated('[3.10] use entity.cw_edited.skip_security')
def skip_security_attributes(self):
return self.cw_edited.skip_security
@property
@deprecated('[3.10] use entity.cw_edited.skip_security')
def _cw_skip_security_attributes(self):
return self.cw_edited.skip_security
@property
@deprecated('[3.10] use entity.cw_edited.querier_pending_relations')
def querier_pending_relations(self):
return self.cw_edited.querier_pending_relations
@deprecated('[3.10] use key in entity.cw_attr_cache')
def __contains__(self, key):
return key in self.cw_attr_cache
@deprecated('[3.10] iter on entity.cw_attr_cache')
def __iter__(self):
return iter(self.cw_attr_cache)
@deprecated('[3.10] use entity.cw_attr_cache[attr]')
def __getitem__(self, key):
if key == 'eid':
warn('[3.7] entity["eid"] is deprecated, use entity.eid instead',
DeprecationWarning, stacklevel=2)
return self.eid
return self.cw_attr_cache[key]
@deprecated('[3.10] use entity.cw_attr_cache.get(attr[, default])')
def get(self, key, default=None):
return self.cw_attr_cache.get(key, default)
@deprecated('[3.10] use entity.cw_attr_cache.clear()')
def clear(self):
self.cw_attr_cache.clear()
# XXX clear cw_edited ?
@deprecated('[3.10] use entity.cw_edited[attr] = value or entity.cw_attr_cache[attr] = value')
def __setitem__(self, attr, value):
"""override __setitem__ to update self.cw_edited.
Typically, a before_[update|add]_hook could do::
entity['generated_attr'] = generated_value
and this way, cw_edited will be updated accordingly. Also, add
the attribute to skip_security since we don't want to check security
for such attributes set by hooks.
"""
if attr == 'eid':
warn('[3.7] entity["eid"] = value is deprecated, use entity.eid = value instead',
DeprecationWarning, stacklevel=2)
self.eid = value
else:
try:
self.cw_edited[attr] = value
except AttributeError:
self.cw_attr_cache[attr] = value
@deprecated('[3.10] use del entity.cw_edited[attr]')
def __delitem__(self, attr):
"""override __delitem__ to update self.cw_edited on cleanup of
undesired changes introduced in the entity's dict. For example, see the
code snippet below from the `forge` cube:
.. sourcecode:: python
edited = self.entity.cw_edited
has_load_left = 'load_left' in edited
if 'load' in edited and self.entity.load_left is None:
self.entity.load_left = self.entity['load']
elif not has_load_left and edited:
# cleanup, this may cause undesired changes
del self.entity['load_left']
"""
del self.cw_edited[attr]
@deprecated('[3.10] use entity.cw_edited.setdefault(attr, default)')
def setdefault(self, attr, default):
"""override setdefault to update self.cw_edited"""
return self.cw_edited.setdefault(attr, default)
@deprecated('[3.10] use entity.cw_edited.pop(attr[, default])')
def pop(self, attr, *args):
"""override pop to update self.cw_edited on cleanup of
undesired changes introduced in the entity's dict. See `__delitem__`
"""
return self.cw_edited.pop(attr, *args)
@deprecated('[3.10] use entity.cw_edited.update(values)')
def update(self, values):
"""override update to update self.cw_edited. See `__setitem__`
"""
self.cw_edited.update(values)
# attribute and relation descriptors ##########################################
class Attribute(object):
"""descriptor that controls schema attribute access"""
def __init__(self, attrname):
assert attrname != 'eid'
self._attrname = attrname
def __get__(self, eobj, eclass):
if eobj is None:
return self
return eobj.cw_attr_value(self._attrname)
@deprecated('[3.10] assign to entity.cw_attr_cache[attr] or entity.cw_edited[attr]')
def __set__(self, eobj, value):
if hasattr(eobj, 'cw_edited') and not eobj.cw_edited.saved:
eobj.cw_edited[self._attrname] = value
else:
eobj.cw_attr_cache[self._attrname] = value
class Relation(object):
"""descriptor that controls schema relation access"""
def __init__(self, rschema, role):
self._rtype = rschema.type
self._role = role
def __get__(self, eobj, eclass):
if eobj is None:
raise AttributeError('%s can only be accessed from instances'
% self._rtype)
return eobj.related(self._rtype, self._role, entities=True)
def __set__(self, eobj, value):
raise NotImplementedError
from logging import getLogger
from cubicweb import set_log_methods
set_log_methods(Entity, getLogger('cubicweb.entity'))