# copyright 2003-2016 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"""
from warnings import warn
from six import text_type, string_types, integer_types
from six.moves import range
from logilab.common.decorators import cached
from logilab.common.deprecation import deprecated
from logilab.common.registry import yes
from logilab.mtconverter import TransformData, xml_escape
from rql.utils import rqlvar_maker
from rql.stmts import Select
from rql.nodes import (Not, VariableRef, Constant, make_relation,
Relation as RqlRelation)
from cubicweb import Unauthorized, neg_role
from cubicweb.utils import support_args
from cubicweb.rset import ResultSet
from cubicweb.appobject import AppObject
from cubicweb.schema import (RQLVocabularyConstraint, RQLConstraint,
GeneratedConstraint)
from cubicweb.rqlrewrite import RQLRewriter
from cubicweb.uilib import soup2xhtml
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 = text_type(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 rel_vars(rel):
return ((isinstance(rel.children[0], VariableRef)
and rel.children[0].variable or None),
(isinstance(rel.children[1].children[0], VariableRef)
and rel.children[1].children[0].variable or None)
)
def rel_matches(rel, rtype, role, varname, operator='='):
if rel.r_type == rtype and rel.children[1].operator == operator:
same_role_var_idx = 0 if role == 'subject' else 1
variables = rel_vars(rel)
if variables[same_role_var_idx].name == varname:
return variables[1 - same_role_var_idx]
def build_cstr_with_linkto_infos(cstr, args, searchedvar, evar,
lt_infos, eidvars):
"""restrict vocabulary as much as possible in entity creation,
based on infos provided by __linkto form param.
Example based on following schema:
class works_in(RelationDefinition):
subject = 'CWUser'
object = 'Lab'
cardinality = '1*'
constraints = [RQLConstraint('S in_group G, O welcomes G')]
class welcomes(RelationDefinition):
subject = 'Lab'
object = 'CWGroup'
If you create a CWUser in the "scientists" CWGroup you can show
only the labs that welcome them using :
lt_infos = {('in_group', 'subject'): 321}
You get following restriction : 'O welcomes G, G eid 321'
"""
st = cstr.snippet_rqlst.copy()
# replace relations in ST by eid infos from linkto where possible
for (info_rtype, info_role), eids in lt_infos.items():
eid = eids[0] # NOTE: we currently assume a pruned lt_info with only 1 eid
for rel in st.iget_nodes(RqlRelation):
targetvar = rel_matches(rel, info_rtype, info_role, evar.name)
if targetvar is not None:
if targetvar.name in eidvars:
rel.parent.remove(rel)
else:
eidrel = make_relation(
targetvar, 'eid', (targetvar.name, 'Substitute'),
Constant)
rel.parent.replace(rel, eidrel)
args[targetvar.name] = eid
eidvars.add(targetvar.name)
# if modified ST still contains evar references we must discard the
# constraint, otherwise evar is unknown in the final rql query which can
# lead to a SQL table cartesian product and multiple occurences of solutions
evarname = evar.name
for rel in st.iget_nodes(RqlRelation):
for variable in rel_vars(rel):
if variable and evarname == variable.name:
return
# else insert snippets into the global tree
return GeneratedConstraint(st, cstr.mainvars - set(evarname))
def pruned_lt_info(eschema, lt_infos):
pruned = {}
for (lt_rtype, lt_role), eids in lt_infos.items():
# we can only use lt_infos describing relation with a cardinality
# of value 1 towards the linked entity
if not len(eids) == 1:
continue
lt_card = eschema.rdef(lt_rtype, lt_role).cardinality[
0 if lt_role == 'subject' else 1]
if lt_card not in '?1':
continue
pruned[(lt_rtype, lt_role)] = eids
return pruned
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 *NEVER* 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_attr: str
:cvar rest_attr: indicates which attribute should be used to build REST urls
If `None` is specified (the default), the first unique attribute will
be used ('eid' if none found)
: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 role == 'subject':
attr = rschema.type
else:
attr = 'reverse_%s' % rschema.type
setattr(cls, attr, Relation(rschema, role))
fetch_attrs = ('modification_date',)
[docs] @classmethod
def cw_fetch_order(cls, select, attr, var):
"""This class method may be used to control sort order when multiple
entities of this type are fetched through ORM methods. Its arguments
are:
* `select`, the RQL syntax tree
* `attr`, the attribute being watched
* `var`, the variable through which this attribute's value may be
accessed in the query
When you want to do some sorting on the given attribute, you should
modify the syntax tree accordingly. For instance:
.. sourcecode:: python
from rql import nodes
class Version(AnyEntity):
__regid__ = 'Version'
fetch_attrs = ('num', 'description', 'in_state')
@classmethod
def cw_fetch_order(cls, select, attr, var):
if attr == 'num':
func = nodes.Function('version_sort_value')
func.append(nodes.variable_ref(var))
sterm = nodes.SortTerm(func, asc=False)
select.add_sort_term(sterm)
The default implementation call
:meth:`~cubicweb.entity.Entity.cw_fetch_unrelated_order`
"""
cls.cw_fetch_unrelated_order(select, attr, var)
@classmethod
def fetch_rql(cls, user, restriction=None, fetchattrs=None, mainvar='X',
settype=True, ordermethod='fetch_order'):
st = cls.fetch_rqlst(user, mainvar=mainvar, fetchattrs=fetchattrs,
settype=settype, ordermethod=ordermethod)
rql = st.as_string()
if restriction:
# cannot use RQLRewriter API to insert 'X rtype %(x)s' restriction
warn('[3.14] fetch_rql: use of `restriction` parameter is '
'deprecated, please use fetch_rqlst and supply a syntax'
'tree with your restriction instead', DeprecationWarning)
insert = ' WHERE ' + ','.join(restriction)
if ' WHERE ' in rql:
select, where = rql.split(' WHERE ', 1)
rql = select + insert + ',' + where
else:
rql += insert
return rql
@classmethod
def fetch_rqlst(cls, user, select=None, mainvar='X', fetchattrs=None,
settype=True, ordermethod='fetch_order'):
if select is None:
select = Select()
mainvar = select.get_variable(mainvar)
select.add_selected(mainvar)
elif isinstance(mainvar, string_types):
assert mainvar in select.defined_vars
mainvar = select.get_variable(mainvar)
# eases string -> syntax tree test transition: please remove once stable
select._varmaker = rqlvar_maker(defined=select.defined_vars,
aliases=select.aliases, index=26)
if settype:
rel = select.add_type_restriction(mainvar, cls.__regid__)
# should use 'is_instance_of' instead of 'is' so we retrieve
# subclasses instances as well
rel.r_type = 'is_instance_of'
if fetchattrs is None:
fetchattrs = cls.fetch_attrs
cls._fetch_restrictions(mainvar, select, fetchattrs, user, ordermethod)
return select
@classmethod
def _fetch_ambiguous_rtypes(cls, select, var, fetchattrs, subjtypes, schema):
"""find rtypes in `fetchattrs` that relate different subject etypes
taken from (`subjtypes`) to different target etypes; these so called
"ambiguous" relations, are added directly to the `select` syntax tree
selection but removed from `fetchattrs` to avoid the fetch recursion
because we have to choose only one targettype for the recursion and
adding its own fetch attrs to the selection -when we recurse- would
filter out the other possible target types from the result set
"""
for attr in fetchattrs.copy():
rschema = schema.rschema(attr)
if rschema.final:
continue
ttypes = None
for subjtype in subjtypes:
cur_ttypes = set(rschema.objects(subjtype))
if ttypes is None:
ttypes = cur_ttypes
elif cur_ttypes != ttypes:
# we found an ambiguous relation: remove it from fetchattrs
fetchattrs.remove(attr)
# ... and add it to the selection
targetvar = select.make_variable()
select.add_selected(targetvar)
rel = make_relation(var, attr, (targetvar,), VariableRef)
select.add_restriction(rel)
break
@classmethod
def _fetch_restrictions(cls, mainvar, select, fetchattrs,
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)
for attr in sorted(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
# XXX takefirst=True to remove warning triggered by ambiguous inlined relations
rdef = eschema.rdef(attr, takefirst=True)
if not user.matching_groups(rdef.get_groups('read')):
continue
if rschema.final or rdef.cardinality[0] in '?1':
var = select.make_variable()
select.add_selected(var)
rel = make_relation(mainvar, attr, (var,), VariableRef)
select.add_restriction(rel)
else:
cls.warning('bad relation %s specified in fetch attrs for %s',
attr, cls)
continue
if not rschema.final:
# 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.
rel.change_optional('right')
targettypes = rschema.objects(eschema.type)
vreg = user._cw.vreg # XXX user._cw.vreg iiiirk
etypecls = vreg['etypes'].etype_class(targettypes[0])
if len(targettypes) > 1:
# find fetch_attrs common to all destination types
fetchattrs = vreg['etypes'].fetch_attrs(targettypes)
# ... and handle ambiguous relations
cls._fetch_ambiguous_rtypes(select, var, fetchattrs,
targettypes, vreg.schema)
else:
fetchattrs = etypecls.fetch_attrs
etypecls._fetch_restrictions(var, select, fetchattrs,
user, None, visited=visited)
if ordermethod is not None:
try:
cmeth = getattr(cls, ordermethod)
warn('[3.14] %s %s class method should be renamed to cw_%s'
% (cls.__regid__, ordermethod, ordermethod),
DeprecationWarning)
except AttributeError:
cmeth = getattr(cls, 'cw_' + ordermethod)
if support_args(cmeth, 'select'):
cmeth(select, attr, var)
else:
warn('[3.14] %s should now take (select, attr, var) and '
'modify the syntax tree when desired instead of '
'returning something' % cmeth, DeprecationWarning)
orderterm = cmeth(attr, var.name)
if orderterm is not None:
try:
var, order = orderterm.split()
except ValueError:
if '(' in orderterm:
cls.error('ignore %s until %s is upgraded',
orderterm, cmeth)
orderterm = None
elif not ' ' in orderterm.strip():
var = orderterm
order = 'ASC'
if orderterm is not None:
select.add_sort_var(select.get_variable(var),
order=='ASC')
@classmethod
@cached
def cw_rest_attr_info(cls):
"""this class method return an attribute name to be used in URL for
entities of this type and a boolean flag telling if its value should be
checked for uniqness.
The attribute returned is, in order of priority:
* class's `rest_attr` class attribute
* an attribute defined as unique in the class'schema
* 'eid'
"""
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 not in ('eid', 'cwuri')
and cls.e_schema.has_unique_values(rschema)
and cls.e_schema.rdef(rschema.type).cardinality[0] == '1'):
mainattr = str(rschema)
needcheck = False
break
if mainattr == 'eid':
needcheck = False
return mainattr, needcheck
@classmethod
def _cw_build_entity_query(cls, kwargs):
relations = []
restrictions = set()
pendingrels = []
eschema = cls.e_schema
qargs = {}
attrcache = {}
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) == 0:
continue # avoid crash with empty IN clause
elif len(value) == 1:
value = next(iter(value))
else:
# prepare IN clause
pendingrels.append( (attr, role, value) )
continue
if rschema.final: # attribute
relations.append('X %s %%(%s)s' % (attr, attr))
attrcache[attr] = value
elif value is None:
pendingrels.append( (attr, role, value) )
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
rql = u''
if relations:
rql += ', '.join(relations)
if restrictions:
rql += ' WHERE %s' % ', '.join(restrictions)
return rql, qargs, pendingrels, attrcache
@classmethod
def _cw_handle_pending_relations(cls, eid, pendingrels, execute):
for attr, role, values in pendingrels:
if role == 'object':
restr = 'Y %s X' % attr
else:
restr = 'X %s Y' % attr
if values is None:
execute('DELETE %s WHERE X eid %%(x)s' % restr, {'x': eid})
continue
execute('SET %s WHERE X eid %%(x)s, Y eid IN (%s)' % (
restr, ','.join(str(getattr(r, 'eid', r)) for r in values)),
{'x': eid}, build_descr=False)
@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 relations where the entity has 'object' role by
prefixing the relation name by 'reverse_'. Also, relation values may be
an entity or eid, a list of entities or eids.
"""
rql, qargs, pendingrels, attrcache = cls._cw_build_entity_query(kwargs)
if rql:
rql = 'INSERT %s X: %s' % (cls.__regid__, rql)
else:
rql = 'INSERT %s X' % (cls.__regid__)
try:
created = execute(rql, qargs).get_entity(0, 0)
except IndexError:
raise Exception('could not create a %r with %r (%r)' %
(cls.__regid__, rql, qargs))
created._cw_update_attr_cache(attrcache)
cls._cw_handle_pending_relations(created.eid, pendingrels, execute)
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 = {}
self._cw_adapters_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, list(self.cw_attr_cache), id(self))
def __lt__(self, other):
return NotImplemented
def __eq__(self, other):
if isinstance(self.eid, integer_types):
return self.eid == other.eid
return self is other
def __hash__(self):
if isinstance(self.eid, integer_types):
return self.eid
return super(Entity, self).__hash__()
def _cw_update_attr_cache(self, attrcache):
trdata = self._cw.transaction_data
uncached_attrs = trdata.get('%s.storage-special-process-attrs' % self.eid, set())
uncached_attrs.update(trdata.get('%s.dont-cache-attrs' % self.eid, set()))
for attr in uncached_attrs:
attrcache.pop(attr, None)
self.cw_attr_cache.pop(attr, None)
self.cw_attr_cache.update(attrcache)
def _cw_dont_cache_attribute(self, attr, repo_side=False):
"""Called when some attribute has been transformed by a *storage*,
hence the original value should not be cached **by anyone**.
For example we have a special "fs_importing" mode in BFSS
where a file path is given as attribute value and stored as is
in the data base. Later access to the attribute will provide
the content of the file at the specified path. We do not want
the "filepath" value to be cached.
"""
trdata = self._cw.transaction_data
trdata.setdefault('%s.dont-cache-attrs' % self.eid, set()).add(attr)
if repo_side:
trdata.setdefault('%s.storage-special-process-attrs' % self.eid, set()).add(attr)
def __json_encode__(self):
"""custom json dumps hook to dump the entity's eid
which is not part of dict structure itself
"""
dumpable = self.cw_attr_cache.copy()
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.
"""
cache = self._cw_adapters_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:
int(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
@deprecated('[3.24] cw_metainformation is deprecated')
@cached
def cw_metainformation(self):
source = self.cw_source[0].name
return {'type': self.cw_etype,
'extid': self.cwuri if source != 'system' else None,
'source': {'uri': source}}
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
if method in (None, 'view'):
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, *args, **kwargs): # XXX cw_rest_path
"""returns a REST-like (relative) path for this entity"""
if args or kwargs:
warn("[3.24] rest_path doesn't take parameters anymore", DeprecationWarning)
mainattr, needcheck = self.cw_rest_attr_info()
etype = str(self.e_schema)
path = etype.lower()
fallback = False
if mainattr != 'eid':
value = getattr(self, mainattr)
if not can_use_rest_path(value):
mainattr = 'eid'
path = None
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 = None
if mainattr == 'eid':
value = self.eid
if path is None:
# fallback url: <base-url>/<eid> url is used as cw entities uri,
# prefer it to <base-url>/<etype>/eid/<eid>
return text_type(value)
return u'%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, string_types):
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 = self._cw.printable_value(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 target_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_copy_for instead with list of couples (rtype, role)' % self.cw_etype,
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.type in skip_copy_for['subject']:
continue
if rschema.final or rschema.meta or rschema.rule:
continue
# skip already defined relations
if getattr(self, rschema.type):
continue
# XXX takefirst=True to remove warning triggered by ambiguous relations
rdef = self.e_schema.rdef(rschema, takefirst=True)
# 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[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 or rschema.rule:
continue
# skip already defined relations
if self.related(rschema.type, 'object'):
continue
if rschema.type in skip_copy_for['object']:
continue
# XXX takefirst=True to remove warning triggered by ambiguous relations
rdef = self.e_schema.rdef(rschema, 'object', takefirst=True)
# 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.cw_etype,)])
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 retrieval 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 = next(varmaker)
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 attr in self.cw_attr_cache:
continue
# case where attribute must be completed, but is not yet in entity
var = next(varmaker)
rql.append('%s %s %s' % (V, attr, var))
selected.append((attr, var))
# +1 since this doesn't include the main variable
lastattr = len(selected) + 1
if attributes is None:
# 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 = next(varmaker)
# 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 range(1, lastattr):
self.cw_attr_cache[str(selected[i-1][0])] = rset[i]
# handle relations
for i in range(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
safe=False, targettypes=None):
"""returns a resultset of related entities
:param rtype:
the name of the relation, aka relation type
:param role:
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
:param safe:
if True, an empty rset/list of entities will be returned in case of
:exc:`Unauthorized`, else (the default), the exception is propagated
:param targettypes:
a tuple of target entity types to restrict the query
"""
rtype = str(rtype)
# Caching restricted/limited results is best avoided.
cacheable = limit is None and targettypes is None
if cacheable:
cache_key = '%s_%s' % (rtype, role)
if cache_key in self._cw_related_cache:
return self._cw_related_cache[cache_key][entities]
if not self.has_eid():
if entities:
return []
return self._cw.empty_rset()
rql = self.cw_related_rql(rtype, role, limit=limit, targettypes=targettypes)
try:
rset = self._cw.execute(rql, {'x': self.eid})
except Unauthorized:
if not safe:
raise
rset = self._cw.empty_rset()
if cacheable:
self.cw_set_relation_cache(rtype, role, rset)
if entities:
return tuple(rset.entities())
else:
return rset
def cw_related_rql(self, rtype, role='subject', targettypes=None, limit=None):
return self.cw_related_rqlst(
rtype, role=role, targettypes=targettypes, limit=limit).as_string()
def cw_related_rqlst(self, rtype, role='subject', targettypes=None,
limit=None, sort_terms=None):
"""Return the select node of the RQL query of entities related through
`rtype` with this entity as `role`, possibly filtered by
`targettypes`.
The RQL query can be given a `limit` and sort terms with `sort_terms`
arguments being a sequence of ``(<relation type>, <sort ascending>)``
(e.g. ``[('name', True), ('modification_date', False)]`` would lead to
a sorting by ``name``, ascending and then by ``modification_date``,
descending. If `sort_terms` is not specified the default sorting is by
``modification_date``, descending.
"""
vreg = self._cw.vreg
rschema = vreg.schema[rtype]
select = Select()
mainvar, evar = select.get_variable('X'), select.get_variable('E')
select.add_selected(mainvar)
if limit is not None:
select.set_limit(limit)
select.add_eid_restriction(evar, 'x', 'Substitute')
if role == 'subject':
rel = make_relation(evar, rtype, (mainvar,), VariableRef)
select.add_restriction(rel)
if targettypes is None:
targettypes = rschema.objects(self.e_schema)
else:
select.add_constant_restriction(mainvar, 'is',
targettypes, 'etype')
gcard = greater_card(rschema, (self.e_schema,), targettypes, 0)
else:
rel = make_relation(mainvar, rtype, (evar,), VariableRef)
select.add_restriction(rel)
if targettypes is None:
targettypes = rschema.subjects(self.e_schema)
else:
select.add_constant_restriction(mainvar, 'is', targettypes,
'etype')
gcard = greater_card(rschema, targettypes, (self.e_schema,), 1)
etypecls = vreg['etypes'].etype_class(targettypes[0])
if len(targettypes) > 1:
fetchattrs = vreg['etypes'].fetch_attrs(targettypes)
self._fetch_ambiguous_rtypes(select, mainvar, fetchattrs,
targettypes, vreg.schema)
else:
fetchattrs = etypecls.fetch_attrs
etypecls.fetch_rqlst(self._cw.user, select, mainvar, fetchattrs,
settype=False)
# optimisation: remove ORDERBY if cardinality is 1 or ? (though
# greater_card return 1 for those both cases)
if gcard == '1':
select.remove_sort_terms()
elif not select.orderby:
# Build a mapping (rtype, node) for relations usable for sorting.
sorting_relations = {}
for r in select.where.get_nodes(RqlRelation):
lhs, rhs = r.children
if lhs.variable != mainvar:
continue
if r.operator() != '=':
continue
rhs_term = rhs.children[0]
if not isinstance(rhs_term, VariableRef):
continue
sorting_relations[r.r_type] = r
sort_terms = sort_terms or [('modification_date', False)]
for term, order in sort_terms:
# Add a relation for sorting only if it is not only retrieved
# (e.g. modification_date) instead of adding another variable
# for sorting. This should not be problematic, but it is with
# sqlserver, see ticket #694445.
rel = sorting_relations.get(term)
if rel is None:
mdvar = select.make_variable()
rel = make_relation(mainvar, term, (mdvar,), VariableRef)
select.add_restriction(rel)
var = rel.children[1].children[0].variable
select.add_sort_var(var, asc=order)
return select
# generic vocabulary methods ##############################################
def cw_linkable_rql(self, rtype, targettype, role, ordermethod=None,
vocabconstraints=True, lt_infos={}, limit=None):
"""build a rql to fetch targettype entities either related or unrelated
to this entity using (rtype, role) relation.
Consider relation permissions so that returned entities may be actually
linked by `rtype`.
`lt_infos` are supplementary informations, usually coming from __linkto
parameter, that can help further restricting the results in case current
entity is not yet created. It is a dict describing entities the current
entity will be linked to, which keys are (rtype, role) tuples and values
are a list of eids.
"""
return self._cw_compute_linkable_rql(rtype, targettype, role, ordermethod=None,
vocabconstraints=vocabconstraints,
lt_infos=lt_infos, limit=limit,
unrelated_only=False)
def cw_unrelated_rql(self, rtype, targettype, role, ordermethod=None,
vocabconstraints=True, lt_infos={}, limit=None):
"""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`.
`lt_infos` are supplementary informations, usually coming from __linkto
parameter, that can help further restricting the results in case current
entity is not yet created. It is a dict describing entities the current
entity will be linked to, which keys are (rtype, role) tuples and values
are a list of eids.
"""
return self._cw_compute_linkable_rql(rtype, targettype, role, ordermethod=None,
vocabconstraints=vocabconstraints,
lt_infos=lt_infos, limit=limit,
unrelated_only=True)
def _cw_compute_linkable_rql(self, rtype, targettype, role, ordermethod=None,
vocabconstraints=True, lt_infos={}, limit=None,
unrelated_only=False):
"""build a rql to fetch `targettype` entities that may be related to
this entity using the (rtype, role) relation.
By default (unrelated_only=False), this includes the already linked
entities as well as the unrelated ones. If `unrelated_only` is True, the
rql filters out the already related entities.
"""
ordermethod = ordermethod or 'fetch_unrelated_order'
rschema = self._cw.vreg.schema.rschema(rtype)
rdef = rschema.role_rdef(self.e_schema, targettype, role)
rewriter = RQLRewriter(self._cw)
select = Select()
# initialize some variables according to the `role` of `self` in the
# relation (variable names must respect constraints conventions):
# * variable for myself (`evar`)
# * variable for searched entities (`searchvedvar`)
if role == 'subject':
evar = subjvar = select.get_variable('S')
searchedvar = objvar = select.get_variable('O')
else:
searchedvar = subjvar = select.get_variable('S')
evar = objvar = select.get_variable('O')
select.add_selected(searchedvar)
if limit is not None:
select.set_limit(limit)
# initialize some variables according to `self` existence
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
variable = select.make_variable()
if role == 'subject':
rel = make_relation(variable, rtype, (searchedvar,), VariableRef)
else:
rel = make_relation(searchedvar, rtype, (variable,), VariableRef)
select.add_restriction(Not(rel))
elif self.has_eid() and unrelated_only:
# elif we have an eid, we don't want a target entity which is
# already linked to ourself through this relation
rel = make_relation(subjvar, rtype, (objvar,), VariableRef)
select.add_restriction(Not(rel))
if self.has_eid():
rel = make_relation(evar, 'eid', ('x', 'Substitute'), Constant)
select.add_restriction(rel)
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.name
# undefine unused evar, or the type resolver will consider it
select.undefine_variable(evar)
# retrieve entity class for targettype to compute base rql
etypecls = self._cw.vreg['etypes'].etype_class(targettype)
etypecls.fetch_rqlst(self._cw.user, select, searchedvar,
ordermethod=ordermethod)
# from now on, we need variable type resolving
self._cw.vreg.solutions(self._cw, select, args)
# insert RQL expressions for schema constraints into the rql syntax tree
if vocabconstraints:
cstrcls = (RQLVocabularyConstraint, RQLConstraint)
else:
cstrcls = RQLConstraint
lt_infos = pruned_lt_info(self.e_schema, lt_infos or {})
# if there are still lt_infos, use set to keep track of added eid
# relations (adding twice the same eid relation is incorrect RQL)
eidvars = set()
for cstr in rdef.constraints:
# consider constraint.mainvars to check if constraint apply
if isinstance(cstr, cstrcls) and searchedvar.name in cstr.mainvars:
if not self.has_eid():
if lt_infos:
# we can perhaps further restrict with linkto infos using
# a custom constraint built from cstr and lt_infos
cstr = build_cstr_with_linkto_infos(
cstr, args, searchedvar, evar, lt_infos, eidvars)
if cstr is None:
continue # could not build constraint -> discard
elif evar.name in cstr.mainvars:
continue
# compute a varmap suitable to RQLRewriter.rewrite argument
varmap = dict((v, v) for v in (searchedvar.name, evar.name)
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,))], 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 not self.has_eid():
rqlexprs = [rqlexpr for rqlexpr in rqlexprs
if searchedvar.name in rqlexpr.mainvars]
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 (searchedvar.name, evar.name)
if v in select.defined_vars)
# rewrite all expressions at once since we want a OR between them.
rewriter.rewrite(select, [(varmap, rqlexprs)], args, existant)
# ensure we have an order defined
if not select.orderby:
select.add_sort_var(select.defined_vars[searchedvar.name])
# 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, lt_infos={}): # 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, limit=limit,
ordermethod=ordermethod, lt_infos=lt_infos)
except Unauthorized:
return self._cw.empty_rset()
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_set_relation_cache(self, rtype, role, rset):
"""set cached values for the given relation"""
if rset:
related = tuple(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.clear()
self._cw_adapters_cache.clear()
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 cw_set(self, **kwargs):
"""update this entity using given attributes / relation, working in the
same fashion as :meth:`cw_instantiate`.
Example (in a shell session):
>>> c = rql('Any X WHERE X is Company').get_entity(0, 0)
>>> p = rql('Any X WHERE X is Person').get_entity(0, 0)
>>> c.cw_set(name=u'Logilab')
>>> p.cw_set(firstname=u'John', lastname=u'Doe', works_for=c)
You can also set relations where the entity has 'object' role by
prefixing the relation name by 'reverse_'. Also, relation 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).
"""
assert kwargs
assert self.cw_is_saved(), "should not call set_attributes while entity "\
"hasn't been saved yet"
rql, qargs, pendingrels, attrcache = self._cw_build_entity_query(kwargs)
if rql:
rql = 'SET ' + rql
qargs['x'] = self.eid
if ' WHERE ' in rql:
rql += ', X eid %(x)s'
else:
rql += ' WHERE X eid %(x)s'
self._cw.execute(rql, qargs)
# 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_update_attr_cache(attrcache)
self._cw_handle_pending_relations(self.eid, pendingrels, self._cw.execute)
# XXX update relation cache
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('[3.16] use cw_set() instead of set_attributes()')
def set_attributes(self, **kwargs): # XXX cw_set_attributes
if kwargs:
self.cw_set(**kwargs)
@deprecated('[3.16] use cw_set() instead of set_relations()')
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).
"""
if kwargs:
self.cw_set(**kwargs)
@deprecated('[3.13] use entity.cw_clear_all_caches()')
def clear_all_caches(self):
return self.cw_clear_all_caches()
# 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'))
