204 

   205     @classmethod

   206     def cw_instantiate(cls, execute, **kwargs):

   207         """add a new entity of this given type

   208 

   209         Example (in a shell session):

   210 

   211         >>> companycls = vreg['etypes'].etype_class(('Company')

   212         >>> personcls = vreg['etypes'].etype_class(('Person')

   213         >>> c = companycls.cw_instantiate(req.execute, name=u'Logilab')

   214         >>> personcls.cw_instantiate(req.execute, firstname=u'John', lastname=u'Doe',

   215         ...                          works_for=c)

   216 

   217         """

   218         rql = 'INSERT %s X' % cls.__regid__

   219         relations = []

   220         restrictions = set()

   221         pending_relations = []

   222         for attr, value in kwargs.items():

   223             if isinstance(value, (tuple, list, set, frozenset)):

   224                 if len(value) == 1:

   225                     value = iter(value).next()

   226                 else:

   227                     del kwargs[attr]

   228                     pending_relations.append( (attr, value) )

   229                     continue

   230             if hasattr(value, 'eid'): # non final relation

   231                 rvar = attr.upper()

   232                 # XXX safer detection of object relation

   233                 if attr.startswith('reverse_'):

   234                     relations.append('%s %s X' % (rvar, attr[len('reverse_'):]))

   235                 else:

   236                     relations.append('X %s %s' % (attr, rvar))

   237                 restriction = '%s eid %%(%s)s' % (rvar, attr)

   238                 if not restriction in restrictions:

   239                     restrictions.add(restriction)

   240                 kwargs[attr] = value.eid

   241             else: # attribute

   242                 relations.append('X %s %%(%s)s' % (attr, attr))

   243         if relations:

   244             rql = '%s: %s' % (rql, ', '.join(relations))

   245         if restrictions:

   246             rql = '%s WHERE %s' % (rql, ', '.join(restrictions))

   247         created = execute(rql, kwargs).get_entity(0, 0)

   248         for attr, values in pending_relations:

   249             if attr.startswith('reverse_'):

   250                 restr = 'Y %s X' % attr[len('reverse_'):]

   251             else:

   252                 restr = 'X %s Y' % attr

   253             execute('SET %s WHERE X eid %%(x)s, Y eid IN (%s)' % (

   254                 restr, ','.join(str(r.eid) for r in values)),

   255                     {'x': created.eid}, build_descr=False)

   256         return created