"""This file contains some basic selectors required by application objects.
A selector is responsible to score how well an object may be used with a
given context by returning a score.
In CubicWeb Usually the context consists for a request object, a result set
or None, a specific row/col in the result set, etc...
If you have trouble with selectors, especially if the objet (typically
a view or a component) you want to use is not selected and you want to
know which one(s) of its selectors fail (e.g. returns 0), you can use
`traced_selection` or even direclty `TRACED_OIDS`.
`TRACED_OIDS` is a tuple of traced object ids. The special value
'all' may be used to log selectors for all objects.
For instance, say that the following code yields a `NoSelectableObject`
exception::
self.view('calendar', myrset)
You can log the selectors involved for *calendar* by replacing the line
above by::
# in Python2.5
from cubicweb.selectors import traced_selection
with traced_selection():
self.view('calendar', myrset)
# in Python2.4
from cubicweb import selectors
selectors.TRACED_OIDS = ('calendar',)
self.view('calendar', myrset)
selectors.TRACED_OIDS = ()
:organization: Logilab
:copyright: 2001-2010 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"
import logging
from warnings import warn, filterwarnings
from logilab.common.deprecation import class_renamed
from logilab.common.compat import all, any
from logilab.common.interface import implements as implements_iface
from yams import BASE_TYPES
from cubicweb import (Unauthorized, NoSelectableObject, NotAnEntity,
role, typed_eid)
# even if not used, let yes here so it's importable through this module
from cubicweb.appobject import Selector, objectify_selector, yes
from cubicweb.vregistry import class_regid
from cubicweb.cwconfig import CubicWebConfiguration
from cubicweb.schema import split_expression
# helpers for debugging selectors
SELECTOR_LOGGER = logging.getLogger('cubicweb.selectors')
TRACED_OIDS = ()
def lltrace(selector):
# don't wrap selectors if not in development mode
if CubicWebConfiguration.mode == 'system': # XXX config.debug
return selector
def traced(cls, *args, **kwargs):
# /!\ lltrace decorates pure function or __call__ method, this
# means argument order may be different
if isinstance(cls, Selector):
selname = str(cls)
vobj = args[0]
else:
selname = selector.__name__
vobj = cls
oid = class_regid(vobj)
ret = selector(cls, *args, **kwargs)
if TRACED_OIDS == 'all' or oid in TRACED_OIDS:
#SELECTOR_LOGGER.warning('selector %s returned %s for %s', selname, ret, cls)
print '%s -> %s for %s(%s)' % (selname, ret, vobj, vobj.__regid__)
return ret
traced.__name__ = selector.__name__
traced.__doc__ = selector.__doc__
return traced
class traced_selection(object):
"""selector debugging helper.
Typical usage is :
>>> with traced_selection():
... # some code in which you want to debug selectors
... # for all objects
or
>>> with traced_selection( ('oid1', 'oid2') ):
... # some code in which you want to debug selectors
... # for objects with id 'oid1' and 'oid2'
"""
def __init__(self, traced='all'):
self.traced = traced
def __enter__(self):
global TRACED_OIDS
TRACED_OIDS = self.traced
def __exit__(self, exctype, exc, traceback):
global TRACED_OIDS
TRACED_OIDS = ()
return traceback is None
def score_interface(etypesreg, cls_or_inst, cls, iface):
"""Return XXX if the give object (maybe an instance or class) implements
the interface.
"""
if getattr(iface, '__registry__', None) == 'etypes':
# adjust score if the interface is an entity class
parents = etypesreg.parent_classes(cls_or_inst.__regid__)
if iface is cls:
return len(parents) + 4
if iface is parents[-1]: # Any
return 1
for index, basecls in enumerate(reversed(parents[:-1])):
if iface is basecls:
return index + 3
return 0
if implements_iface(cls_or_inst, iface):
# implenting an interface takes precedence other special Any interface
return 2
return 0
# abstract selectors ##########################################################
class PartialSelectorMixIn(object):
"""convenience mix-in for selectors that will look into the containing
class to find missing information.
cf. `cubicweb.web.action.LinkToEntityAction` for instance
"""
def __call__(self, cls, *args, **kwargs):
self.complete(cls)
return super(PartialSelectorMixIn, self).__call__(cls, *args, **kwargs)
class ImplementsMixIn(object):
"""mix-in class for selectors checking implemented interfaces of something
"""
def __init__(self, *expected_ifaces, **kwargs):
super(ImplementsMixIn, self).__init__(**kwargs)
self.expected_ifaces = expected_ifaces
def __str__(self):
return '%s(%s)' % (self.__class__.__name__,
','.join(str(s) for s in self.expected_ifaces))
def score_interfaces(self, req, cls_or_inst, cls):
score = 0
etypesreg = req.vreg['etypes']
eschema = cls_or_inst.e_schema
for iface in self.expected_ifaces:
if isinstance(iface, basestring):
# entity type
try:
iface = etypesreg.etype_class(iface)
except KeyError:
continue # entity type not in the schema
score += score_interface(etypesreg, cls_or_inst, cls, iface)
return score
class EClassSelector(Selector):
"""abstract class for selectors working on the entity classes of the result
set. Its __call__ method has the following behaviour:
* if 'entity' find in kwargs, return the score returned by the score_class
method for this entity's class
* elif row is specified, return the score returned by the score_class method
called with the entity class found in the specified cell
* else return the sum of score returned by the score_class method for each
entity type found in the specified column, unless:
- `once_is_enough` is True, in which case the first non-zero score is
returned
- `once_is_enough` is False, in which case if score_class return 0, 0 is
returned
"""
def __init__(self, once_is_enough=False, accept_none=True):
self.once_is_enough = once_is_enough
self.accept_none = accept_none
@lltrace
def __call__(self, cls, req, rset=None, row=None, col=0, **kwargs):
if kwargs.get('entity'):
return self.score_class(kwargs['entity'].__class__, req)
if not rset:
return 0
score = 0
if row is None:
if not self.accept_none:
if any(rset[i][col] is None for i in xrange(len(rset))):
return 0
for etype in rset.column_types(col):
if etype is None: # outer join
return 0
escore = self.score(cls, req, etype)
if not escore and not self.once_is_enough:
return 0
elif self.once_is_enough:
return escore
score += escore
else:
etype = rset.description[row][col]
if etype is not None:
score = self.score(cls, req, etype)
return score
def score(self, cls, req, etype):
if etype in BASE_TYPES:
return 0
return self.score_class(req.vreg['etypes'].etype_class(etype), req)
def score_class(self, eclass, req):
raise NotImplementedError()
class EntitySelector(EClassSelector):
"""abstract class for selectors working on the entity instances of the
result set. Its __call__ method has the following behaviour:
* if 'entity' find in kwargs, return the score returned by the score_entity
method for this entity
* if row is specified, return the score returned by the score_entity method
called with the entity instance found in the specified cell
* else return the sum of score returned by the score_entity method for each
entity found in the specified column, unless:
- `once_is_enough` is True, in which case the first non-zero score is
returned
- `once_is_enough` is False, in which case if score_class return 0, 0 is
returned
note: None values (resulting from some outer join in the query) are not
considered.
"""
@lltrace
def __call__(self, cls, req, rset=None, row=None, col=0, **kwargs):
if not rset and not kwargs.get('entity'):
return 0
score = 0
if kwargs.get('entity'):
score = self.score_entity(kwargs['entity'])
elif row is None:
col = col or 0
for row, rowvalue in enumerate(rset.rows):
if rowvalue[col] is None: # outer join
continue
escore = self.score(req, rset, row, col)
if not escore and not self.once_is_enough:
return 0
elif self.once_is_enough:
return escore
score += escore
else:
col = col or 0
etype = rset.description[row][col]
if etype is not None: # outer join
score = self.score(req, rset, row, col)
return score
def score(self, req, rset, row, col):
try:
return self.score_entity(rset.get_entity(row, col))
except NotAnEntity:
return 0
def score_entity(self, entity):
raise NotImplementedError()
# very basic selectors ########################################################
@objectify_selector
@lltrace
def none_rset(cls, req, rset=None, **kwargs):
"""accept no result set (e.g. given rset is None)"""
if rset is None:
return 1
return 0
@objectify_selector
@lltrace
def any_rset(cls, req, rset=None, **kwargs):
"""accept result set, whatever the number of result it contains"""
if rset is not None:
return 1
return 0
@objectify_selector
@lltrace
def nonempty_rset(cls, req, rset=None, **kwargs):
"""accept any non empty result set"""
if rset is not None and rset.rowcount:
return 1
return 0
@objectify_selector
@lltrace
def empty_rset(cls, req, rset=None, **kwargs):
"""accept empty result set"""
if rset is not None and rset.rowcount == 0:
return 1
return 0
@objectify_selector
@lltrace
def one_line_rset(cls, req, rset=None, row=None, **kwargs):
"""if row is specified, accept result set with a single line of result,
else accepts anyway
"""
if rset is not None and (row is not None or rset.rowcount == 1):
return 1
return 0
class multi_lines_rset(Selector):
def __init__(self, nb=None):
self.expected = nb
def match_expected(self, num):
if self.expected is None:
return num > 1
return num == self.expected
@lltrace
def __call__(self, cls, req, rset=None, row=None, col=0, **kwargs):
return rset is not None and self.match_expected(rset.rowcount)
class multi_columns_rset(multi_lines_rset):
@lltrace
def __call__(self, cls, req, rset=None, row=None, col=0, **kwargs):
return rset and self.match_expected(len(rset.rows[0])) or 0 # *must not* return None
@objectify_selector
@lltrace
def paginated_rset(cls, req, rset=None, **kwargs):
"""accept result set with more lines than the page size.
Page size is searched in (respecting order):
* a page_size argument
* a page_size form parameters
* the navigation.page-size property
"""
page_size = kwargs.get('page_size')
if page_size is None:
page_size = req.form.get('page_size')
if page_size is None:
page_size = req.property_value('navigation.page-size')
else:
page_size = int(page_size)
if rset is None or rset.rowcount <= page_size:
return 0
return 1
@objectify_selector
@lltrace
def sorted_rset(cls, req, rset=None, **kwargs):
"""accept sorted result set"""
rqlst = rset.syntax_tree()
if len(rqlst.children) > 1 or not rqlst.children[0].orderby:
return 0
return 2
@objectify_selector
@lltrace
def one_etype_rset(cls, req, rset=None, col=0, **kwargs):
"""accept result set where entities in the specified column (or 0) are all
of the same type
"""
if rset is None:
return 0
if len(rset.column_types(col)) != 1:
return 0
return 1
class multi_etypes_rset(multi_lines_rset):
@lltrace
def __call__(self, cls, req, rset=None, col=0, **kwargs):
return rset and self.match_expected(len(rset.column_types(col)))
class non_final_entity(EClassSelector):
"""accept if entity type found in the result set is non final.
See `EClassSelector` documentation for behaviour when row is not specified.
"""
def score(self, cls, req, etype):
if etype in BASE_TYPES:
return 0
return 1
@objectify_selector
@lltrace
def authenticated_user(cls, req, *args, **kwargs):
"""accept if user is authenticated"""
if req.cnx.anonymous_connection:
return 0
return 1
def anonymous_user():
return ~ authenticated_user()
@objectify_selector
@lltrace
def primary_view(cls, req, rset=None, row=None, col=0, view=None, **kwargs):
"""accept if view given as named argument is a primary view, or if no view
is given
"""
if view is not None and not view.is_primary():
return 0
return 1
@objectify_selector
@lltrace
def match_context_prop(cls, req, rset=None, row=None, col=0, context=None,
**kwargs):
"""accept if:
* no context given
* context (`basestring`) is matching the context property value for the
given cls
"""
propval = req.property_value('%s.%s.context' % (cls.__registry__,
cls.__regid__))
if not propval:
propval = cls.context
if context is not None and propval and context != propval:
return 0
return 1
class match_search_state(Selector):
"""accept if the current request search state is in one of the expected
states given to the initializer
:param expected: either 'normal' or 'linksearch' (eg searching for an
object to create a relation with another)
"""
def __init__(self, *expected):
assert expected, self
self.expected = frozenset(expected)
def __str__(self):
return '%s(%s)' % (self.__class__.__name__,
','.join(sorted(str(s) for s in self.expected)))
@lltrace
def __call__(self, cls, req, rset=None, row=None, col=0, **kwargs):
try:
if not req.search_state[0] in self.expected:
return 0
except AttributeError:
return 1 # class doesn't care about search state, accept it
return 1
class match_form_params(match_search_state):
"""accept if parameters specified as initializer arguments are specified
in request's form parameters
:param *expected: parameters (eg `basestring`) which are expected to be
found in request's form parameters
"""
@lltrace
def __call__(self, cls, req, *args, **kwargs):
score = 0
for param in self.expected:
if not param in req.form:
return 0
score += 1
return len(self.expected)
class match_kwargs(match_search_state):
"""accept if parameters specified as initializer arguments are specified
in named arguments given to the selector
:param *expected: parameters (eg `basestring`) which are expected to be
found in named arguments (kwargs)
"""
@lltrace
def __call__(self, cls, req, *args, **kwargs):
for arg in self.expected:
if not arg in kwargs:
return 0
return len(self.expected)
class match_user_groups(match_search_state):
"""accept if logged users is in at least one of the given groups. Returned
score is the number of groups in which the user is.
If the special 'owners' group is given:
* if row is specified check the entity at the given row/col is owned by the
logged user
* if row is not specified check all entities in col are owned by the logged
user
:param *required_groups: name of groups (`basestring`) in which the logged
user should be
"""
@lltrace
def __call__(self, cls, req, rset=None, row=None, col=0, **kwargs):
user = req.user
if user is None:
return int('guests' in self.expected)
score = user.matching_groups(self.expected)
if not score and 'owners' in self.expected and rset:
if row is not None:
if not user.owns(rset[row][col]):
return 0
score = 1
else:
score = all(user.owns(r[col]) for r in rset)
return score
class match_transition(match_search_state):
@lltrace
def __call__(self, cls, req, rset=None, row=None, col=0, **kwargs):
try:
# XXX check this is a transition that apply to the object?
if not kwargs['transition'].name in self.expected:
return 0
except KeyError:
return 0
return 1
class match_view(match_search_state):
"""accept if the current view is in one of the expected vid given to the
initializer
"""
@lltrace
def __call__(self, cls, req, rset=None, row=None, col=0, view=None, **kwargs):
if view is None or not view.__regid__ in self.expected:
return 0
return 1
class appobject_selectable(Selector):
"""accept with another appobject is selectable using selector's input
context.
:param registry: a registry name (`basestring`)
:param oid: an object identifier (`basestring`)
"""
def __init__(self, registry, oid):
self.registry = registry
self.oid = oid
def __call__(self, cls, req, **kwargs):
try:
req.vreg[self.registry].select(self.oid, req, **kwargs)
return 1
except NoSelectableObject:
return 0
# not so basic selectors ######################################################
class implements(ImplementsMixIn, EClassSelector):
"""accept if entity classes found in the result set implements at least one
of the interfaces given as argument. Returned score is the number of
implemented interfaces.
See `EClassSelector` documentation for behaviour when row is not specified.
:param *expected_ifaces: expected interfaces. An interface may be a class
or an entity type (e.g. `basestring`) in which case
the associated class will be searched in the
registry (at selection time)
note: when interface is an entity class, the score will reflect class
proximity so the most specific object'll be selected
"""
def score_class(self, eclass, req):
return self.score_interfaces(req, eclass, eclass)
class specified_etype_implements(implements):
"""accept if entity class specified using an 'etype' parameters in name
argument or request form implements at least one of the interfaces given as
argument. Returned score is the number of implemented interfaces.
:param *expected_ifaces: expected interfaces. An interface may be a class
or an entity type (e.g. `basestring`) in which case
the associated class will be searched in the
registry (at selection time)
note: when interface is an entity class, the score will reflect class
proximity so the most specific object'll be selected
"""
@lltrace
def __call__(self, cls, req, *args, **kwargs):
try:
etype = kwargs['etype']
except KeyError:
try:
etype = req.form['etype']
except KeyError:
return 0
else:
# only check this is a known type if etype comes from req.form,
# else we want the error to propagate
try:
etype = req.vreg.case_insensitive_etypes[etype.lower()]
req.form['etype'] = etype
except KeyError:
return 0
score = self.score_class(req.vreg['etypes'].etype_class(etype), req)
if score:
eschema = req.vreg.schema.eschema(etype)
if eschema.has_local_role('add') or eschema.has_perm(req, 'add'):
return score
return 0
class relation_possible(EClassSelector):
"""accept if entity class found in the result set support the relation.
See `EClassSelector` documentation for behaviour when row is not specified.
:param rtype: a relation type (`basestring`)
:param role: the role of the result set entity in the relation. 'subject' or
'object', default to 'subject'.
:param target_type: if specified, check the relation's end may be of this
target type (`basestring`)
:param action: a relation schema action (one of 'read', 'add', 'delete')
which must be granted to the logged user, else a 0 score will
be returned
"""
def __init__(self, rtype, role='subject', target_etype=None,
action='read', once_is_enough=False):
super(relation_possible, self).__init__(once_is_enough)
self.rtype = rtype
self.role = role
self.target_etype = target_etype
self.action = action
def score_class(self, eclass, req):
eschema = eclass.e_schema
try:
if self.role == 'object':
rschema = eschema.objrels[self.rtype]
else:
rschema = eschema.subjrels[self.rtype]
except KeyError:
return 0
if self.target_etype is not None:
try:
rdef = rschema.role_rdef(eschema, self.target_etype, self.role)
if not rdef.may_have_permission(self.action, req):
return 0
except KeyError:
return 0
else:
return rschema.may_have_permission(self.action, req, eschema, self.role)
return 1
class partial_relation_possible(PartialSelectorMixIn, relation_possible):
"""partial version of the relation_possible selector
The selector will look for class attributes to find its missing
information. The list of attributes required on the class
for this selector are:
- `rtype`: same as `rtype` parameter of the `relation_possible` selector
- `role`: this attribute will be passed to the `cubicweb.role` function
to determine the role of class in the relation
- `etype` (optional): the entity type on the other side of the relation
:param action: a relation schema action (one of 'read', 'add', 'delete')
which must be granted to the logged user, else a 0 score will
be returned
"""
def __init__(self, action='read', once_is_enough=False):
super(partial_relation_possible, self).__init__(None, None, None,
action, once_is_enough)
def complete(self, cls):
self.rtype = cls.rtype
self.role = role(cls)
self.target_etype = getattr(cls, 'etype', None)
class may_add_relation(EntitySelector):
"""accept if the relation can be added to an entity found in the result set
by the logged user.
See `EntitySelector` documentation for behaviour when row is not specified.
:param rtype: a relation type (`basestring`)
:param role: the role of the result set entity in the relation. 'subject' or
'object', default to 'subject'.
"""
def __init__(self, rtype, role='subject', target_etype=None,
once_is_enough=False):
super(may_add_relation, self).__init__(once_is_enough)
self.rtype = rtype
self.role = role
self.target_etype = target_etype
def score_entity(self, entity):
rschema = entity._cw.vreg.schema.rschema(self.rtype)
if self.target_etype is not None:
rschema = rschema.role_rdef(entity.e_schema, self.target_etype, self.role)
if self.role == 'subject':
if not rschema.has_perm(entity._cw, 'add', fromeid=entity.eid):
return 0
elif not rschema.has_perm(entity._cw, 'add', toeid=entity.eid):
return 0
return 1
class partial_may_add_relation(PartialSelectorMixIn, may_add_relation):
"""partial version of the may_add_relation selector
The selector will look for class attributes to find its missing
information. The list of attributes required on the class
for this selector are:
- `rtype`: same as `rtype` parameter of the `relation_possible` selector
- `role`: this attribute will be passed to the `cubicweb.role` function
to determine the role of class in the relation.
:param action: a relation schema action (one of 'read', 'add', 'delete')
which must be granted to the logged user, else a 0 score will
be returned
"""
def __init__(self, once_is_enough=False):
super(partial_may_add_relation, self).__init__(None, once_is_enough=once_is_enough)
def complete(self, cls):
self.rtype = cls.rtype
self.role = role(cls)
self.target_etype = getattr(cls, 'etype', None)
class has_related_entities(EntitySelector):
"""accept if entity found in the result set has some linked entities using
the specified relation (optionaly filtered according to the specified target
type). Checks first if the relation is possible.
See `EntitySelector` documentation for behaviour when row is not specified.
:param rtype: a relation type (`basestring`)
:param role: the role of the result set entity in the relation. 'subject' or
'object', default to 'subject'.
:param target_type: if specified, check the relation's end may be of this
target type (`basestring`)
"""
def __init__(self, rtype, role='subject', target_etype=None,
once_is_enough=False):
super(has_related_entities, self).__init__(once_is_enough)
self.rtype = rtype
self.role = role
self.target_etype = target_etype
def score_entity(self, entity):
relpossel = relation_possible(self.rtype, self.role, self.target_etype)
if not relpossel.score_class(entity.__class__, entity._cw):
return 0
rset = entity.related(self.rtype, self.role)
if self.target_etype:
return any(r for r in rset.description if r[0] == self.target_etype)
return rset and 1 or 0
class partial_has_related_entities(PartialSelectorMixIn, has_related_entities):
"""partial version of the has_related_entities selector
The selector will look for class attributes to find its missing
information. The list of attributes required on the class
for this selector are:
- `rtype`: same as `rtype` parameter of the `relation_possible` selector
- `role`: this attribute will be passed to the `cubicweb.role` function
to determine the role of class in the relation.
- `etype` (optional): the entity type on the other side of the relation
:param action: a relation schema action (one of 'read', 'add', 'delete')
which must be granted to the logged user, else a 0 score will
be returned
"""
def __init__(self, once_is_enough=False):
super(partial_has_related_entities, self).__init__(None, None,
None, once_is_enough)
def complete(self, cls):
self.rtype = cls.rtype
self.role = role(cls)
self.target_etype = getattr(cls, 'etype', None)
class has_permission(EntitySelector):
"""accept if user has the permission to do the requested action on a result
set entity.
* if row is specified, return 1 if user has the permission on the entity
instance found in the specified cell
* else return a positive score if user has the permission for every entity
in the found in the specified column
note: None values (resulting from some outer join in the query) are not
considered.
:param action: an entity schema action (eg 'read'/'add'/'delete'/'update')
"""
def __init__(self, action, once_is_enough=False):
super(has_permission, self).__init__(once_is_enough)
self.action = action
@lltrace
def __call__(self, cls, req, rset=None, row=None, col=0, **kwargs):
if rset is None:
return 0
user = req.user
action = self.action
if row is None:
score = 0
need_local_check = []
geteschema = req.vreg.schema.eschema
for etype in rset.column_types(0):
if etype in BASE_TYPES:
return 0
eschema = geteschema(etype)
if not user.matching_groups(eschema.get_groups(action)):
if eschema.has_local_role(action):
# have to ckeck local roles
need_local_check.append(eschema)
continue
else:
# even a local role won't be enough
return 0
score += 1
if need_local_check:
# check local role for entities of necessary types
for i, row in enumerate(rset):
if not rset.description[i][0] in need_local_check:
continue
if not self.score(req, rset, i, col):
return 0
score += 1
return score
return self.score(req, rset, row, col)
def score_entity(self, entity):
if entity.has_perm(self.action):
return 1
return 0
class has_add_permission(EClassSelector):
"""accept if logged user has the add permission on entity class found in the
result set, and class is not a strict subobject.
See `EClassSelector` documentation for behaviour when row is not specified.
"""
def score(self, cls, req, etype):
eschema = req.vreg.schema.eschema(etype)
if not (eschema.final or eschema.is_subobject(strict=True)) \
and eschema.has_perm(req, 'add'):
return 1
return 0
class rql_condition(EntitySelector):
"""accept if an arbitrary rql return some results for an eid found in the
result set. Returned score is the number of items returned by the rql
condition.
See `EntitySelector` documentation for behaviour when row is not specified.
:param expression: basestring containing an rql expression, which should use
X variable to represent the context entity and may use U
to represent the logged user
return the sum of the number of items returned by the rql condition as score
or 0 at the first entity scoring to zero.
"""
def __init__(self, expression, once_is_enough=False):
super(rql_condition, self).__init__(once_is_enough)
if 'U' in frozenset(split_expression(expression)):
rql = 'Any X WHERE X eid %%(x)s, U eid %%(u)s, %s' % expression
else:
rql = 'Any X WHERE X eid %%(x)s, %s' % expression
self.rql = rql
def score(self, req, rset, row, col):
try:
return len(req.execute(self.rql, {'x': rset[row][col],
'u': req.user.eid}, 'x'))
except Unauthorized:
return 0
def __repr__(self):
return u'<rql_condition "%s" at %x>' % (self.rql, id(self))
class score_entity(EntitySelector):
"""accept if some arbitrary function return a positive score for an entity
found in the result set.
See `EntitySelector` documentation for behaviour when row is not specified.
:param scorefunc: callable expected to take an entity as argument and to
return a score >= 0
"""
def __init__(self, scorefunc, once_is_enough=False):
super(score_entity, self).__init__(once_is_enough)
def intscore(*args, **kwargs):
score = scorefunc(*args, **kwargs)
if not score:
return 0
if isinstance(score, (int, long)):
return score
return 1
self.score_entity = intscore
## deprecated stuff ############################################################
entity_implements = class_renamed('entity_implements', implements)
class _but_etype(EntitySelector):
"""accept if the given entity types are not found in the result set.
See `EntitySelector` documentation for behaviour when row is not specified.
:param *etypes: entity types (`basestring`) which should be refused
"""
def __init__(self, *etypes):
super(_but_etype, self).__init__()
self.but_etypes = etypes
def score(self, req, rset, row, col):
if rset.description[row][col] in self.but_etypes:
return 0
return 1
but_etype = class_renamed('but_etype', _but_etype, 'use ~implements(*etypes) instead')
# XXX deprecated the one_* variants of selectors below w/ multi_xxx(nb=1)?
# take care at the implementation though (looking for the 'row' argument's
# value)
two_lines_rset = class_renamed('two_lines_rset', multi_lines_rset)
two_cols_rset = class_renamed('two_cols_rset', multi_columns_rset)
two_etypes_rset = class_renamed('two_etypes_rset', multi_etypes_rset)