entity.py 63 KB
Newer Older
1
# copyright 2003-2012 LOGILAB S.A. (Paris, FRANCE), all rights reserved.
2
3
4
5
6
7
8
9
10
# 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.
#
11
# CubicWeb is distributed in the hope that it will be useful, but WITHOUT
12
13
14
15
16
17
# 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/>.
18
"""Base class for entity objects manipulated in clients"""
Adrien Di Mascio's avatar
Adrien Di Mascio committed
19
20
21

__docformat__ = "restructuredtext en"

22
23
from warnings import warn

Adrien Di Mascio's avatar
Adrien Di Mascio committed
24
25
from logilab.common import interface
from logilab.common.decorators import cached
26
from logilab.common.deprecation import deprecated
27
from logilab.common.registry import yes
Sylvain Thénault's avatar
Sylvain Thénault committed
28
from logilab.mtconverter import TransformData, TransformError, xml_escape
29

Adrien Di Mascio's avatar
Adrien Di Mascio committed
30
from rql.utils import rqlvar_maker
31
32
33
from rql.stmts import Select
from rql.nodes import (Not, VariableRef, Constant, make_relation,
                       Relation as RqlRelation)
Adrien Di Mascio's avatar
Adrien Di Mascio committed
34

35
from cubicweb import Unauthorized, typed_eid, neg_role
36
from cubicweb.utils import support_args
Adrien Di Mascio's avatar
Adrien Di Mascio committed
37
from cubicweb.rset import ResultSet
38
from cubicweb.appobject import AppObject
39
from cubicweb.req import _check_cw_unsafe
40
41
from cubicweb.schema import (RQLVocabularyConstraint, RQLConstraint,
                             GeneratedConstraint)
42
from cubicweb.rqlrewrite import RQLRewriter
43

44
from cubicweb.uilib import soup2xhtml
Sylvain Thénault's avatar
Sylvain Thénault committed
45
46
from cubicweb.mixins import MI_REL_TRIGGERS
from cubicweb.mttransforms import ENGINE
Adrien Di Mascio's avatar
Adrien Di Mascio committed
47
48
49
50
51
52

_marker = object()

def greater_card(rschema, subjtypes, objtypes, index):
    for subjtype in subjtypes:
        for objtype in objtypes:
Sylvain Thénault's avatar
Sylvain Thénault committed
53
            card = rschema.rdef(subjtype, objtype).cardinality[index]
Adrien Di Mascio's avatar
Adrien Di Mascio committed
54
55
56
57
            if card in '+*':
                return card
    return '1'

58
59
60
61
62
63
64
65
66
67
68
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

69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
91
92
93
94
95
96
97
98
99
100
101
102
103
104
105
106
107
108
109
110
111
112
113
114
115
116
117
118
119
120
121
122
123
124
125
126
127
128
129
130
131
132
133
134
135
136
137
138
139
140
141
142
143
144
145
146
147
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.iteritems():
        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.iteritems():
        # 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
148

149
class Entity(AppObject):
150
151
    """an entity instance has e_schema automagically set on
    the class and instances has access to their issuing cursor.
152

153
154
155
156
    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)
Adrien Di Mascio's avatar
Adrien Di Mascio committed
157
158
159
160

    :type e_schema: `cubicweb.schema.EntitySchema`
    :ivar e_schema: the entity's schema

161
162
163
164
    :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)
165

166
167
    :type cw_skip_copy_for: list
    :cvar cw_skip_copy_for: a list of couples (rtype, role) for each relation
168
169
170
       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.
Adrien Di Mascio's avatar
Adrien Di Mascio committed
171
172
    """
    __registry__ = 'etypes'
173
    __select__ = yes()
174

175
    # class attributes that must be set in class definition
Adrien Di Mascio's avatar
Adrien Di Mascio committed
176
    rest_attr = None
177
    fetch_attrs = None
178
179
    skip_copy_for = () # bw compat (< 3.14), use cw_skip_copy_for instead
    cw_skip_copy_for = [('in_state', 'subject')]
180
181
    # class attributes set automatically at registration time
    e_schema = None
182

Adrien Di Mascio's avatar
Adrien Di Mascio committed
183
    @classmethod
184
    def __initialize__(cls, schema):
Adrien Di Mascio's avatar
Adrien Di Mascio committed
185
186
187
        """initialize a specific entity class by adding descriptors to access
        entity type's attributes and relations
        """
188
        etype = cls.__regid__
Adrien Di Mascio's avatar
Adrien Di Mascio committed
189
        assert etype != 'Any', etype
190
        cls.e_schema = eschema = schema.eschema(etype)
Adrien Di Mascio's avatar
Adrien Di Mascio committed
191
        for rschema, _ in eschema.attribute_definitions():
192
            if rschema.type == 'eid':
Adrien Di Mascio's avatar
Adrien Di Mascio committed
193
                continue
194
            setattr(cls, rschema.type, Attribute(rschema.type))
Adrien Di Mascio's avatar
Adrien Di Mascio committed
195
        mixins = []
196
197
198
        for rschema, _, role in eschema.relation_definitions():
            if (rschema, role) in MI_REL_TRIGGERS:
                mixin = MI_REL_TRIGGERS[(rschema, role)]
Adrien Di Mascio's avatar
Adrien Di Mascio committed
199
200
201
202
203
                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)
204
            if role == 'subject':
205
                attr = rschema.type
Adrien Di Mascio's avatar
Adrien Di Mascio committed
206
            else:
207
                attr = 'reverse_%s' % rschema.type
208
            setattr(cls, attr, Relation(rschema, role))
Adrien Di Mascio's avatar
Adrien Di Mascio committed
209
        if mixins:
210
211
212
213
214
215
216
217
218
219
220
221
            # 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)
222

223
    fetch_attrs = ('modification_date',)
224

225
    @classmethod
226
227
228
229
230
231
232
233
234
235
236
237
238
239
240
241
242
243
244
245
246
247
248
249
250
251
252
253
254
255
256
257
258
259
    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`
260
        """
261
        cls.cw_fetch_unrelated_order(select, attr, var)
262
263

    @classmethod
264
265
266
    def cw_fetch_unrelated_order(cls, select, attr, var):
        """This class method may be used to control sort order when multiple entities of
        this type are fetched to use in edition (e.g. propose them to create a
267
        new relation on an edited entity).
268
269
270
271
272
273

        See :meth:`~cubicweb.entity.Entity.cw_fetch_unrelated_order` for a
        description of its arguments and usage.

        By default entities will be listed on their modification date descending,
        i.e. you'll get entities recently modified first.
274
275
        """
        if attr == 'modification_date':
276
            select.add_sort_var(var, asc=False)
277

Adrien Di Mascio's avatar
Adrien Di Mascio committed
278
279
280
    @classmethod
    def fetch_rql(cls, user, restriction=None, fetchattrs=None, mainvar='X',
                  settype=True, ordermethod='fetch_order'):
281
282
283
284
285
286
287
288
289
290
291
292
293
294
295
296
297
298
299
300
301
302
303
304
305
306
307
308
309
        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, basestring):
            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)
Adrien Di Mascio's avatar
Adrien Di Mascio committed
310
        if settype:
311
            select.add_type_restriction(mainvar, cls.__regid__)
Adrien Di Mascio's avatar
Adrien Di Mascio committed
312
313
        if fetchattrs is None:
            fetchattrs = cls.fetch_attrs
314
315
        cls._fetch_restrictions(mainvar, select, fetchattrs, user, ordermethod)
        return select
316

317
318
319
320
321
322
323
324
325
326
327
328
329
330
331
332
333
334
335
336
337
338
339
340
341
342
343
344
345
    @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

Adrien Di Mascio's avatar
Adrien Di Mascio committed
346
    @classmethod
347
348
    def _fetch_restrictions(cls, mainvar, select, fetchattrs,
                            user, ordermethod='fetch_order', visited=None):
Adrien Di Mascio's avatar
Adrien Di Mascio committed
349
350
351
352
353
354
355
356
357
358
359
        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:
360
                rschema = eschema.subjrels[attr]
Adrien Di Mascio's avatar
Adrien Di Mascio committed
361
362
            except KeyError:
                cls.warning('skipping fetch_attr %s defined in %s (not found in schema)',
363
                            attr, cls.__regid__)
Adrien Di Mascio's avatar
Adrien Di Mascio committed
364
                continue
Sylvain Thénault's avatar
Sylvain Thénault committed
365
366
            rdef = eschema.rdef(attr)
            if not user.matching_groups(rdef.get_groups('read')):
Adrien Di Mascio's avatar
Adrien Di Mascio committed
367
                continue
368
369
370
371
372
373
374
375
376
            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
377
            if not rschema.final:
378
379
380
381
                # 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.
382
                rel.change_optional('right')
383
                targettypes = rschema.objects(eschema.type)
384
385
                vreg = user._cw.vreg # XXX user._cw.vreg iiiirk
                etypecls = vreg['etypes'].etype_class(targettypes[0])
386
387
                if len(targettypes) > 1:
                    # find fetch_attrs common to all destination types
388
                    fetchattrs = vreg['etypes'].fetch_attrs(targettypes)
Sylvain Thénault's avatar
Sylvain Thénault committed
389
                    # ... and handle ambiguous relations
390
391
                    cls._fetch_ambiguous_rtypes(select, var, fetchattrs,
                                                targettypes, vreg.schema)
392
393
                else:
                    fetchattrs = etypecls.fetch_attrs
394
                etypecls._fetch_restrictions(var, select, fetchattrs,
395
                                             user, ordermethod, visited=visited)
396
            if ordermethod is not None:
397
398
399
400
401
402
403
404
405
406
407
408
409
410
411
412
413
414
415
                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:
416
417
                                cls.error('ignore %s until %s is upgraded',
                                          orderterm, cmeth)
418
419
420
421
422
423
424
                                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')
Adrien Di Mascio's avatar
Adrien Di Mascio committed
425

426
427
    @classmethod
    @cached
428
429
430
431
432
433
434
435
436
437
438
    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'
        """
439
440
441
442
443
444
        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():
445
446
                if rschema.final and rschema != 'eid' \
                        and cls.e_schema.has_unique_values(rschema):
447
448
449
450
451
452
453
                    mainattr = str(rschema)
                    needcheck = False
                    break
        if mainattr == 'eid':
            needcheck = False
        return mainattr, needcheck

454
    @classmethod
455
    def _cw_build_entity_query(cls, kwargs):
456
457
        relations = []
        restrictions = set()
458
        pendingrels = []
459
        eschema = cls.e_schema
460
        qargs = {}
461
        attrcache = {}
462
        for attr, value in kwargs.items():
463
464
465
466
467
            if attr.startswith('reverse_'):
                attr = attr[len('reverse_'):]
                role = 'object'
            else:
                role = 'subject'
468
            assert eschema.has_relation(attr, role), '%s %s not found on %s' % (attr, role, eschema)
469
            rschema = eschema.subjrels[attr] if role == 'subject' else eschema.objrels[attr]
470
            if not rschema.final and isinstance(value, (tuple, list, set, frozenset)):
471
472
473
                if len(value) == 0:
                    continue # avoid crash with empty IN clause
                elif len(value) == 1:
474
475
                    value = iter(value).next()
                else:
476
                    # prepare IN clause
477
                    pendingrels.append( (attr, role, value) )
478
                    continue
479
480
            if rschema.final: # attribute
                relations.append('X %s %%(%s)s' % (attr, attr))
481
482
                attrcache[attr] = value
            elif value is None:
483
                pendingrels.append( (attr, role, value) )
484
            else:
485
                rvar = attr.upper()
486
487
                if role == 'object':
                    relations.append('%s %s X' % (rvar, attr))
488
489
490
491
492
                else:
                    relations.append('X %s %s' % (attr, rvar))
                restriction = '%s eid %%(%s)s' % (rvar, attr)
                if not restriction in restrictions:
                    restrictions.add(restriction)
493
494
495
                if hasattr(value, 'eid'):
                    value = value.eid
            qargs[attr] = value
496
        rql = u''
497
        if relations:
498
            rql += ', '.join(relations)
499
        if restrictions:
500
            rql += ' WHERE %s' % ', '.join(restrictions)
501
        return rql, qargs, pendingrels, attrcache
502
503

    @classmethod
504
505
    def _cw_handle_pending_relations(cls, eid, pendingrels, execute):
        for attr, role, values in pendingrels:
506
507
            if role == 'object':
                restr = 'Y %s X' % attr
508
509
            else:
                restr = 'X %s Y' % attr
510
511
512
            if values is None:
                execute('DELETE %s WHERE X eid %%(x)s' % restr, {'x': eid})
                continue
513
            execute('SET %s WHERE X eid %%(x)s, Y eid IN (%s)' % (
514
                restr, ','.join(str(getattr(r, 'eid', r)) for r in values)),
515
516
517
518
519
520
521
522
523
524
525
526
527
528
529
530
531
532
                    {'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.
        """
533
        rql, qargs, pendingrels, attrcache = cls._cw_build_entity_query(kwargs)
534
535
536
537
538
        if rql:
            rql = 'INSERT %s X: %s' % (cls.__regid__, rql)
        else:
            rql = 'INSERT %s X' % (cls.__regid__)
        created = execute(rql, qargs).get_entity(0, 0)
539
        created._cw_update_attr_cache(attrcache)
540
        created.cw_attr_cache.update(attrcache)
541
        cls._cw_handle_pending_relations(created.eid, pendingrels, execute)
542
543
        return created

544
    def __init__(self, req, rset=None, row=None, col=0):
545
        AppObject.__init__(self, req, rset=rset, row=row, col=col)
546
        self._cw_related_cache = {}
Adrien Di Mascio's avatar
Adrien Di Mascio committed
547
548
549
550
        if rset is not None:
            self.eid = rset[row][col]
        else:
            self.eid = None
551
        self._cw_is_saved = True
552
        self.cw_attr_cache = {}
553

Adrien Di Mascio's avatar
Adrien Di Mascio committed
554
555
    def __repr__(self):
        return '<Entity %s %s %s at %s>' % (
556
            self.e_schema, self.eid, self.cw_attr_cache.keys(), id(self))
Adrien Di Mascio's avatar
Adrien Di Mascio committed
557

558
559
560
    def __cmp__(self, other):
        raise NotImplementedError('comparison not implemented for %s' % self.__class__)

561
562
563
564
    def _cw_update_attr_cache(self, attrcache):
        for key in self._cw.get_shared_data('%s.dont-cache-attrs' % self.eid,
                                            default=(), txdata=True, pop=True):
            attrcache.pop(key, None)
565
            self.cw_attr_cache.pop(key, None)
566
567
568
569
570
571
572
573
574
        self.cw_attr_cache.update(attrcache)

    def _cw_dont_cache_attribute(self, attr):
        """repository side method called when some attribute have been
        transformed by a hook, hence original value should not be cached by
        client
        """
        self._cw.transaction_data.setdefault('%s.dont-cache-attrs' % self.eid, set()).add(attr)

575
576
577
578
    def __json_encode__(self):
        """custom json dumps hook to dump the entity's eid
        which is not part of dict structure itself
        """
579
        dumpable = self.cw_attr_cache.copy()
580
581
582
        dumpable['eid'] = self.eid
        return dumpable

583
584
585
586
587
588
589
590
591
592
593
594
595
596
597
598
599
    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

600
    def has_eid(self): # XXX cw_has_eid
Adrien Di Mascio's avatar
Adrien Di Mascio committed
601
602
603
604
        """return True if the entity has an attributed eid (False
        meaning that the entity has to be created
        """
        try:
Sylvain Thénault's avatar
Sylvain Thénault committed
605
            typed_eid(self.eid)
Adrien Di Mascio's avatar
Adrien Di Mascio committed
606
607
608
609
            return True
        except (ValueError, TypeError):
            return False

610
    def cw_is_saved(self):
Adrien Di Mascio's avatar
Adrien Di Mascio committed
611
        """during entity creation, there is some time during which the entity
612
613
614
        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.
Adrien Di Mascio's avatar
Adrien Di Mascio committed
615
        """
616
        return self.has_eid() and self._cw_is_saved
617

Adrien Di Mascio's avatar
Adrien Di Mascio committed
618
    @cached
619
    def cw_metainformation(self):
620
621
622
623
        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')]
Adrien Di Mascio's avatar
Adrien Di Mascio committed
624
625
        return res

626
    def cw_check_perm(self, action):
627
        self.e_schema.check_perm(self._cw, action, eid=self.eid)
Adrien Di Mascio's avatar
Adrien Di Mascio committed
628

629
    def cw_has_perm(self, action):
630
        return self.e_schema.has_perm(self._cw, action, eid=self.eid)
631

632
    def view(self, __vid, __registry='views', w=None, initargs=None, **kwargs): # XXX cw_view
Adrien Di Mascio's avatar
Adrien Di Mascio committed
633
        """shortcut to apply a view on this entity"""
634
635
636
637
        if initargs is None:
            initargs = kwargs
        else:
            initargs.update(kwargs)
638
        view = self._cw.vreg[__registry].select(__vid, self._cw, rset=self.cw_rset,
639
                                                row=self.cw_row, col=self.cw_col,
640
                                                **initargs)
641
        return view.render(row=self.cw_row, col=self.cw_col, w=w, **kwargs)
Adrien Di Mascio's avatar
Adrien Di Mascio committed
642

643
    def absolute_url(self, *args, **kwargs): # XXX cw_url
Adrien Di Mascio's avatar
Adrien Di Mascio committed
644
        """return an absolute url to view this entity"""
645
646
647
648
649
650
651
        # 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
Adrien Di Mascio's avatar
Adrien Di Mascio committed
652
653
654
        # 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
655
        use_ext_id = False
656
        if 'base_url' not in kwargs and \
657
               getattr(self._cw, 'search_state', ('normal',))[0] == 'normal':
658
659
660
661
662
            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']
663
                use_ext_id = True
664
        if method in (None, 'view'):
665
            kwargs['_restpath'] = self.rest_path(use_ext_id)
Adrien Di Mascio's avatar
Adrien Di Mascio committed
666
667
        else:
            kwargs['rql'] = 'Any X WHERE X eid %s' % self.eid
668
        return self._cw.build_url(method, **kwargs)
Adrien Di Mascio's avatar
Adrien Di Mascio committed
669

670
    def rest_path(self, use_ext_eid=False): # XXX cw_rest_path
Adrien Di Mascio's avatar
Adrien Di Mascio committed
671
        """returns a REST-like (relative) path for this entity"""
672
        mainattr, needcheck = self.cw_rest_attr_info()
Adrien Di Mascio's avatar
Adrien Di Mascio committed
673
        etype = str(self.e_schema)
674
        path = etype.lower()
675
        fallback = False
676
        if mainattr != 'eid':
677
            value = getattr(self, mainattr)
678
            if not can_use_rest_path(value):
679
                mainattr = 'eid'
680
                path = None
681
682
            elif needcheck:
                # make sure url is not ambiguous
683
684
685
686
687
688
                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]
689
690
                if nbresults != 1: # ambiguity?
                    mainattr = 'eid'
691
                    path = None
Adrien Di Mascio's avatar
Adrien Di Mascio committed
692
        if mainattr == 'eid':
693
            if use_ext_eid:
694
                value = self.cw_metainformation()['extid']
695
696
            else:
                value = self.eid
697
698
699
700
        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 unicode(value)
701
        return '%s/%s' % (path, self._cw.url_quote(value))
Adrien Di Mascio's avatar
Adrien Di Mascio committed
702

703
    def cw_attr_metadata(self, attr, metadata):
704
        """return a metadata for an attribute (None if unspecified)"""
705
        value = getattr(self, '%s_%s' % (attr, metadata), None)
706
        if value is None and metadata == 'encoding':
707
            value = self._cw.vreg.property_value('ui.encoding')
708
        return value
Adrien Di Mascio's avatar
Adrien Di Mascio committed
709
710

    def printable_value(self, attr, value=_marker, attrtype=None,
711
                        format='text/html', displaytime=True): # XXX cw_printable_value
Adrien Di Mascio's avatar
Adrien Di Mascio committed
712
713
714
715
716
        """return a displayable value (i.e. unicode string) which may contains
        html tags
        """
        attr = str(attr)
        if value is _marker:
717
            value = getattr(self, attr)
Adrien Di Mascio's avatar
Adrien Di Mascio committed
718
719
720
721
722
723
        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)
Sylvain Thénault's avatar
Sylvain Thénault committed
724
        props = self.e_schema.rdef(attr)
Adrien Di Mascio's avatar
Adrien Di Mascio committed
725
726
727
        if attrtype == 'String':
            # internalinalized *and* formatted string such as schema
            # description...
Sylvain Thénault's avatar
Sylvain Thénault committed
728
            if props.internationalizable:
729
                value = self._cw._(value)
730
            attrformat = self.cw_attr_metadata(attr, 'format')
Adrien Di Mascio's avatar
Adrien Di Mascio committed
731
            if attrformat:
732
733
                return self._cw_mtc_transform(value, attrformat, format,
                                              self._cw.encoding)
Adrien Di Mascio's avatar
Adrien Di Mascio committed
734
        elif attrtype == 'Bytes':
735
            attrformat = self.cw_attr_metadata(attr, 'format')
Adrien Di Mascio's avatar
Adrien Di Mascio committed
736
            if attrformat:
737
738
739
                encoding = self.cw_attr_metadata(attr, 'encoding')
                return self._cw_mtc_transform(value.getvalue(), attrformat, format,
                                              encoding)
Adrien Di Mascio's avatar
Adrien Di Mascio committed
740
            return u''
741
742
        value = self._cw.printable_value(attrtype, value, props,
                                         displaytime=displaytime)
Adrien Di Mascio's avatar
Adrien Di Mascio committed
743
        if format == 'text/html':
Sylvain Thénault's avatar
Sylvain Thénault committed
744
            value = xml_escape(value)
Adrien Di Mascio's avatar
Adrien Di Mascio committed
745
746
        return value

747
748
    def _cw_mtc_transform(self, data, format, target_format, encoding,
                          _engine=ENGINE):
Adrien Di Mascio's avatar
Adrien Di Mascio committed
749
750
751
        trdata = TransformData(data, format, encoding, appobject=self)
        data = _engine.convert(trdata, target_format).decode()
        if format == 'text/html':
752
            data = soup2xhtml(data, self._cw.encoding)
Adrien Di Mascio's avatar
Adrien Di Mascio committed
753
        return data
754

Adrien Di Mascio's avatar
Adrien Di Mascio committed
755
756
    # entity cloning ##########################################################

757
    def copy_relations(self, ceid): # XXX cw_copy_relations
Alexandre Fayolle's avatar
Alexandre Fayolle committed
758
759
760
        """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).
Adrien Di Mascio's avatar
Adrien Di Mascio committed
761
762
763
764
765

        By default meta and composite relations are skipped.
        Overrides this if you want another behaviour
        """
        assert self.has_eid()
766
        execute = self._cw.execute
767
768
769
770
771
772
773
774
775
        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)
Adrien Di Mascio's avatar
Adrien Di Mascio committed
776
        for rschema in self.e_schema.subject_relations():
777
            if rschema.final or rschema.meta:
Adrien Di Mascio's avatar
Adrien Di Mascio committed
778
                continue
779
780
            # skip already defined relations
            if getattr(self, rschema.type):
Adrien Di Mascio's avatar
Adrien Di Mascio committed
781
                continue
782
            if rschema.type in skip_copy_for['subject']:
Adrien Di Mascio's avatar
Adrien Di Mascio committed
783
                continue
784
            # skip composite relation
Sylvain Thénault's avatar
Sylvain Thénault committed
785
786
            rdef = self.e_schema.rdef(rschema)
            if rdef.composite:
787
788
789
                continue
            # skip relation with card in ?1 else we either change the copied
            # object (inlined relation) or inserting some inconsistency
Sylvain Thénault's avatar
Sylvain Thénault committed
790
            if rdef.cardinality[1] in '?1':
791
                continue
Adrien Di Mascio's avatar
Adrien Di Mascio committed
792
            rql = 'SET X %s V WHERE X eid %%(x)s, Y eid %%(y)s, Y %s V' % (
793
                rschema.type, rschema.type)
794
            execute(rql, {'x': self.eid, 'y': ceid})
795
            self.cw_clear_relation_cache(rschema.type, 'subject')
Adrien Di Mascio's avatar
Adrien Di Mascio committed
796
        for rschema in self.e_schema.object_relations():
797
798
799
            if rschema.meta:
                continue
            # skip already defined relations
Sylvain Thénault's avatar
Sylvain Thénault committed
800
            if self.related(rschema.type, 'object'):
801
                continue
802
803
            if rschema.type in skip_copy_for['object']:
                continue
Sylvain Thénault's avatar
Sylvain Thénault committed
804
            rdef = self.e_schema.rdef(rschema, 'object')
805
            # skip composite relation
Sylvain Thénault's avatar
Sylvain Thénault committed
806
            if rdef.composite:
Adrien Di Mascio's avatar
Adrien Di Mascio committed
807
808
809
                continue
            # skip relation with card in ?1 else we either change the copied
            # object (inlined relation) or inserting some inconsistency
Sylvain Thénault's avatar
Sylvain Thénault committed
810
            if rdef.cardinality[0] in '?1':
Adrien Di Mascio's avatar
Adrien Di Mascio committed
811
812
                continue
            rql = 'SET V %s X WHERE X eid %%(x)s, Y eid %%(y)s, V %s Y' % (
813
                rschema.type, rschema.type)
814
            execute(rql, {'x': self.eid, 'y': ceid})
815
            self.cw_clear_relation_cache(rschema.type, 'object')
Adrien Di Mascio's avatar
Adrien Di Mascio committed
816
817
818
819

    # data fetching methods ###################################################

    @cached
820
    def as_rset(self): # XXX .cw_as_rset
Adrien Di Mascio's avatar
Adrien Di Mascio committed
821
822
        """returns a resultset containing `self` information"""
        rset = ResultSet([(self.eid,)], 'Any X WHERE X eid %(x)s',
823
                         {'x': self.eid}, [(self.__regid__,)])
824
825
        rset.req = self._cw
        return rset
826

827
    def _cw_to_complete_relations(self):
Adrien Di Mascio's avatar
Adrien Di Mascio committed
828
829
        """by default complete final relations to when calling .complete()"""
        for rschema in self.e_schema.subject_relations():
830
            if rschema.final:
Adrien Di Mascio's avatar
Adrien Di Mascio committed
831
                continue
Sylvain Thénault's avatar
Sylvain Thénault committed
832
            targets = rschema.objects(self.e_schema)
Adrien Di Mascio's avatar
Adrien Di Mascio committed
833
            if rschema.inlined:
834
                matching_groups = self._cw.user.matching_groups
835
836
837
                if all(matching_groups(e.get_groups('read')) and
                       rschema.rdef(self.e_schema, e).get_groups('read')
                       for e in targets):
Adrien Di Mascio's avatar
Adrien Di Mascio committed
838
                    yield rschema, 'subject'
839

840
    def _cw_to_complete_attributes(self, skip_bytes=True, skip_pwd=True):
Adrien Di Mascio's avatar
Adrien Di Mascio committed
841
842
843
844
845
846
847
848
        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
Sylvain Thénault's avatar
Sylvain Thénault committed
849
            rdef = rschema.rdef(self.e_schema, attrschema)
850
            if not self._cw.user.matching_groups(rdef.get_groups('read')) \
851
                   or (attrschema.type == 'Password' and skip_pwd):
852
                self.cw_attr_cache[attr] = None
Adrien Di Mascio's avatar
Adrien Di Mascio committed
853
854
                continue
            yield attr
855

856
    _cw_completed = False
857
    def complete(self, attributes=None, skip_bytes=True, skip_pwd=True): # XXX cw_complete
Adrien Di Mascio's avatar
Adrien Di Mascio committed
858
859
860
861
862
863
864
865
        """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()
866
867
868
869
        if self._cw_completed:
            return
        if attributes is None:
            self._cw_completed = True
Adrien Di Mascio's avatar
Adrien Di Mascio committed
870
871
872
873
        varmaker = rqlvar_maker()
        V = varmaker.next()
        rql = ['WHERE %s eid %%(x)s' % V]
        selected = []
874
        for attr in (attributes or self._cw_to_complete_attributes(skip_bytes, skip_pwd)):
Adrien Di Mascio's avatar
Adrien Di Mascio committed
875
            # if attribute already in entity, nothing to do
876
            if self.cw_attr_cache.has_key(attr):
Adrien Di Mascio's avatar
Adrien Di Mascio committed
877
878
879
880
881
                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))
882
        # +1 since this doesn't include the main variable
Adrien Di Mascio's avatar
Adrien Di Mascio committed
883
        lastattr = len(selected) + 1
884
885
886
        # 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':
Adrien Di Mascio's avatar
Adrien Di Mascio committed
887
            # fetch additional relations (restricted to 0..1 relations)
888
            for rschema, role in self._cw_to_complete_relations():
Adrien Di Mascio's avatar
Adrien Di Mascio committed
889
                rtype = rschema.type
890
                if self.cw_relation_cached(rtype, role):
Adrien Di Mascio's avatar
Adrien Di Mascio committed
891
                    continue
892
893
894
895
896
897
                # 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'
Adrien Di Mascio's avatar
Adrien Di Mascio committed
898
                var = varmaker.next()
899
900
901
                # 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))
Adrien Di Mascio's avatar
Adrien Di Mascio committed
902
903
904
905
906
907
                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))
908
909
910
911
912
            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)
Adrien Di Mascio's avatar
Adrien Di Mascio committed
913
914
            # handle attributes
            for i in xrange(1, lastattr):
915
                self.cw_attr_cache[str(selected[i-1][0])] = rset[i]
Adrien Di Mascio's avatar
Adrien Di Mascio committed
916
917
            # handle relations
            for i in xrange(lastattr, len(rset)):
918
                rtype, role = selected[i-1][0]
Adrien Di Mascio's avatar
Adrien Di Mascio committed
919
920
921
                value = rset[i]
                if value is None:
                    rrset = ResultSet([], rql, {'x': self.eid})
922
                    rrset.req = self._cw
Adrien Di Mascio's avatar
Adrien Di Mascio committed
923
                else:
924
                    rrset = self._cw.eid_rset(value)
925
                self.cw_set_relation_cache(rtype, role, rrset)
926

927
    def cw_attr_value(self, name):
Adrien Di Mascio's avatar
Adrien Di Mascio committed
928
929
930
931
932
933
934
        """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:
935
            return self.cw_attr_cache[name]
Adrien Di Mascio's avatar
Adrien Di Mascio committed
936
        except KeyError:
937
            if not self.cw_is_saved():
Adrien Di Mascio's avatar
Adrien Di Mascio committed
938
939
940
                return None
            rql = "Any A WHERE X eid %%(x)s, X %s A" % name
            try:
941
                rset = self._cw.execute(rql, {'x': self.eid})
Adrien Di Mascio's avatar
Adrien Di Mascio committed
942
            except Unauthorized:
943
                self.cw_attr_cache[name] = value = None
Adrien Di Mascio's avatar
Adrien Di Mascio committed
944
945
946
            else:
                assert rset.rowcount <= 1, (self, rql, rset.rowcount)
                try:
947
                    self.cw_attr_cache[name] = value = rset.rows[0][0]
Adrien Di Mascio's avatar
Adrien Di Mascio committed
948
949
950
951
952
                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':
953
                        self.cw_attr_cache[name] = value = self._cw._('unaccessible')
Adrien Di Mascio's avatar
Adrien Di Mascio committed
954
                    else:
955
956
                        self.cw_attr_cache[name] = value = None
            return value
Adrien Di Mascio's avatar
Adrien Di Mascio committed
957

958
959
    def related(self, rtype, role='subject', limit=None, entities=False, # XXX .cw_related
                safe=False):
Adrien Di Mascio's avatar
Adrien Di Mascio committed
960
        """returns a resultset of related entities
961

962
963
964
965
966
967
968
969
970
971
972
        :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
Adrien Di Mascio's avatar
Adrien Di Mascio committed
973
        """
974
        rtype = str(rtype)
Adrien Di Mascio's avatar
Adrien Di Mascio committed
975
        try:
976
            return self._cw_relation_cache(rtype, role, entities, limit)
Adrien Di Mascio's avatar
Adrien Di Mascio committed
977
978
        except KeyError:
            pass
979
980
981
        if not self.has_eid():
            if entities:
                return []
982
            return self._cw.empty_rset()
983
        rql = self.cw_related_rql(rtype, role)
984
985
986
987
988
989
        try:
            rset = self._cw.execute(rql, {'x': self.eid})
        except Unauthorized:
            if not safe:
                raise
            rset = self._cw.empty_rset()
990
        self.cw_set_relation_cache(rtype, role, rset)
Adrien Di Mascio's avatar
Adrien Di Mascio committed
991
992
        return self.related(rtype, role, limit, entities)

993
    def cw_related_rql(self, rtype, role='subject', targettypes=None):
994
995
        vreg = self._cw.vreg
        rschema = vreg.schema[rtype]
996
997
998
999
        select = Select()
        mainvar, evar = select.get_variable('X'), select.get_variable('E')
        select.add_selected(mainvar)
        select.add_eid_restriction(evar, 'x', 'Substitute')
Adrien Di Mascio's avatar
Adrien Di Mascio committed
1000
        if role == 'subject':
1001
1002
            rel = make_relation(evar, rtype, (mainvar,), VariableRef)
            select.add_restriction(rel)
1003
1004
            if targettypes is None:
                targettypes = rschema.objects(self.e_schema)
1005
            else:
1006
1007
1008
                select.add_constant_restriction(mainvar, 'is',
                                                targettypes, 'etype')
            gcard = greater_card(rschema, (self.e_schema,), targettypes, 0)
Adrien Di Mascio's avatar
Adrien Di Mascio committed
1009
        else:
1010
1011
            rel = make_relation(mainvar, rtype, (evar,), VariableRef)
            select.add_restriction(rel)
1012
1013
            if targettypes is None:
                targettypes = rschema.subjects(self.e_schema)
1014
            else:
1015
                select.add_constant_restriction(mainvar, 'is', targettypes,