--- /dev/null Thu Jan 01 00:00:00 1970 +0000
+++ b/goa/db.py Wed Nov 05 15:52:50 2008 +0100
@@ -0,0 +1,460 @@
+"""provide replacement classes for gae db module, so that a gae model can be
+used as base for a cubicweb application by simply replacing ::
+
+ from google.appengine.ext import db
+
+by
+
+ from cubicweb.goa import db
+
+The db.model api should be fully featured by replacement classes, with the
+following differences:
+
+* all methods returning `google.appengine.ext.db.Model` instance(s) will return
+ `cubicweb.goa.db.Model` instance instead (though you should see almost no
+ difference since those instances have the same api)
+
+* class methods returning model instance take a `req` as first argument, unless
+ they are called through an instance, representing the current request
+ (accessible through `self.req` on almost all objects)
+
+* XXX no instance.<modelname>_set attributes, use instance.reverse_<attr name>
+ instead
+* XXX reference property always return a list of objects, not the instance
+* XXX name/collection_name argument of properties constructor are ignored
+* XXX ListProperty
+
+:organization: Logilab
+:copyright: 2008 LOGILAB S.A. (Paris, FRANCE), all rights reserved.
+:contact: http://www.logilab.fr/ -- mailto:contact@logilab.fr
+"""
+__docformat__ = "restructuredtext en"
+
+from datetime import datetime
+from copy import deepcopy
+
+from logilab.common.decorators import cached, iclassmethod
+
+from cubicweb import RequestSessionMixIn, Binary, entities
+from cubicweb.rset import ResultSet
+from cubicweb.common.entity import metaentity
+from cubicweb.server.utils import crypt_password
+from cubicweb.goa import use_mx_for_dates, mx2datetime, MODE
+from cubicweb.goa.dbinit import init_relations
+
+from google.appengine.api.datastore import Get, Put, Key, Entity, Query
+from google.appengine.api.datastore import NormalizeAndTypeCheck, RunInTransaction
+from google.appengine.api.datastore_types import Text, Blob
+from google.appengine.api.datastore_errors import BadKeyError
+
+# XXX remove this dependancy
+from google.appengine.ext import db
+
+
+def rset_from_objs(req, objs, attrs=('eid',), rql=None, args=None):
+ """return a ResultSet instance for list of objects"""
+ if objs is None:
+ objs = ()
+ elif isinstance(objs, Entity):
+ objs = (objs,)
+ if rql is None:
+ rql = 'Any X'
+ rows = []
+ description = []
+ rset = ResultSet(rows, rql, args, description=description)
+ vreg = req.vreg
+ for i, obj in enumerate(objs):
+ line = []
+ linedescr = []
+ eschema = vreg.schema.eschema(obj.kind())
+ for j, attr in enumerate(attrs):
+ if attr == 'eid':
+ value = obj.key()
+ obj.row, obj.col = i, j
+ descr = eschema.type
+ value = str(value)
+ else:
+ value = obj[attr]
+ descr = str(eschema.destination(attr))
+ line.append(value)
+ linedescr.append(descr)
+ rows.append(line)
+ description.append(linedescr)
+ for j, attr in enumerate(attrs):
+ if attr == 'eid':
+ entity = vreg.etype_class(eschema.type)(req, rset, i, j)
+ rset._get_entity_cache_ = {(i, j): entity}
+ rset.rowcount = len(rows)
+ req.decorate_rset(rset)
+ return rset
+
+
+def needrequest(wrapped):
+ def wrapper(cls, *args, **kwargs):
+ req = kwargs.pop('req', None)
+ if req is None and args and isinstance(args[0], RequestSessionMixIn):
+ args = list(args)
+ req = args.pop(0)
+ if req is None:
+ req = getattr(cls, 'req', None)
+ if req is None:
+ raise Exception('either call this method on an instance or '
+ 'specify the req argument')
+ return wrapped(cls, req, *args, **kwargs)
+ return iclassmethod(wrapper)
+
+
+class gaedbmetaentity(metaentity):
+ """metaclass for goa.db.Model classes: filter entity / db model part,
+ put aside the db model part for later creation of db model class.
+ """
+ def __new__(mcs, name, bases, classdict):
+ if not 'id' in classdict:
+ classdict['id'] = name
+ entitycls = super(gaedbmetaentity, mcs).__new__(mcs, name, bases, classdict)
+ return entitycls
+
+
+TEST_MODELS = {}
+
+def extract_dbmodel(entitycls):
+ if MODE == 'test' and entitycls in TEST_MODELS:
+ dbclassdict = TEST_MODELS[entitycls]
+ else:
+ dbclassdict = {}
+ for attr, value in entitycls.__dict__.items():
+ if isinstance(value, db.Property) or isinstance(value, ReferencePropertyStub):
+ dbclassdict[attr] = value
+ # don't remove attr from entitycls, this make tests fail, and it's anyway
+ # overwritten by descriptor at class initialization time
+ #delattr(entitycls, attr)
+ if MODE == 'test':
+ TEST_MODELS[entitycls] = dbclassdict
+ dbclassdict = deepcopy(dbclassdict)
+ for propname, prop in TEST_MODELS[entitycls].iteritems():
+ if getattr(prop, 'reference_class', None) is db._SELF_REFERENCE:
+ dbclassdict[propname].reference_class = db._SELF_REFERENCE
+ return dbclassdict
+
+
+class Model(entities.AnyEntity):
+ id = 'Any'
+ __metaclass__ = gaedbmetaentity
+
+ row = col = 0
+
+ @classmethod
+ def __initialize__(cls):
+ super(Model, cls).__initialize__()
+ cls._attributes = frozenset(rschema for rschema in cls.e_schema.subject_relations()
+ if rschema.is_final())
+
+ def __init__(self, *args, **kwargs):
+ # db.Model prototype:
+ # __init__(self, parent=None, key_name=None, **kw)
+ #
+ # Entity prototype:
+ # __init__(self, req, rset, row=None, col=0)
+ if args and isinstance(args[0], RequestSessionMixIn) or 'req' in kwargs:
+ super(Model, self).__init__(*args, **kwargs)
+ self._gaeinitargs = None
+ else:
+ super(Model, self).__init__(None, None)
+ # if Model instances are given in kwargs, turn them into db model
+ for key, val in kwargs.iteritems():
+ if key in self.e_schema.subject_relations() and not self.e_schema.schema[key].is_final():
+ if isinstance(kwargs, (list, tuple)):
+ val = [isinstance(x, Model) and x._dbmodel or x for x in val]
+ elif isinstance(val, Model):
+ val = val._dbmodel
+ kwargs[key] = val.key()
+ self._gaeinitargs = (args, kwargs)
+
+ def __repr__(self):
+ return '<ModelEntity %s %s %s at %s>' % (
+ self.e_schema, self.eid, self.keys(), id(self))
+
+ __getattribute__ = use_mx_for_dates(entities.AnyEntity.__getattribute__)
+
+ def _cubicweb_to_datastore(self, attr, value):
+ attr = attr[2:] # remove 's_' / 'o_' prefix
+ if attr in self._attributes:
+ tschema = self.e_schema.destination(attr)
+ if tschema in ('Datetime', 'Date', 'Time'):
+ value = mx2datetime(value, tschema)
+ elif tschema == 'String':
+ if len(value) > 500:
+ value = Text(value)
+ elif tschema == 'Password':
+ # if value is a Binary instance, this mean we got it
+ # from a query result and so it is already encrypted
+ if isinstance(value, Binary):
+ value = value.getvalue()
+ else:
+ value = crypt_password(value)
+ elif tschema == 'Bytes':
+ if isinstance(value, Binary):
+ value = value.getvalue()
+ value = Blob(value)
+ else:
+ value = Key(value)
+ return value
+
+ def _to_gae_dict(self, convert=True):
+ gaedict = {}
+ for attr, value in self.iteritems():
+ attr = 's_' + attr
+ if value is not None and convert:
+ value = self._cubicweb_to_datastore(attr, value)
+ gaedict[attr] = value
+ return gaedict
+
+ def to_gae_model(self):
+ dbmodel = self._dbmodel
+ dbmodel.update(self._to_gae_dict())
+ return dbmodel
+
+ @property
+ @cached
+ def _dbmodel(self):
+ if self.has_eid():
+ assert self._gaeinitargs is None
+ try:
+ return self.req.datastore_get(self.eid)
+ except AttributeError: # self.req is not a server session
+ return Get(self.eid)
+ self.set_defaults()
+ values = self._to_gae_dict(convert=False)
+ parent = key_name = _app = None
+ if self._gaeinitargs is not None:
+ args, kwargs = self._gaeinitargs
+ args = list(args)
+ if args:
+ parent = args.pop(0)
+ if args:
+ key_name = args.pop(0)
+ if args:
+ _app = args.pop(0)
+ assert not args
+ if 'parent' in kwargs:
+ assert parent is None
+ parent = kwargs.pop('parent')
+ if 'key_name' in kwargs:
+ assert key_name is None
+ key_name = kwargs.pop('key_name')
+ if '_app' in kwargs:
+ assert _app is None
+ _app = kwargs.pop('_app')
+
+ for key, value in kwargs.iteritems():
+ if key in self._attributes:
+ values['s_'+key] = value
+ else:
+ kwargs = None
+ if key_name is None:
+ key_name = self.db_key_name()
+ if key_name is not None:
+ key_name = 'key_' + key_name
+ for key, value in values.iteritems():
+ if value is None:
+ continue
+ values[key] = self._cubicweb_to_datastore(key, value)
+ entity = Entity(self.id, parent, _app, key_name)
+ entity.update(values)
+ init_relations(entity, self.e_schema)
+ return entity
+
+ def db_key_name(self):
+ """override this method to control datastore key name that should be
+ used at entity creation.
+
+ Note that if this function return something else than None, the returned
+ value will be prefixed by 'key_' to build the actual key name.
+ """
+ return None
+
+ def metainformation(self):
+ return {'type': self.id, 'source': {'uri': 'system'}, 'extid': None}
+
+ def view(self, vid, __registry='views', **kwargs):
+ """shortcut to apply a view on this entity"""
+ return self.vreg.render(__registry, vid, self.req, rset=self.rset,
+ row=self.row, col=self.col, **kwargs)
+
+ @classmethod
+ def _rest_attr_info(cls):
+ mainattr, needcheck = super(Model, cls)._rest_attr_info()
+ if needcheck:
+ return 'eid', False
+ return mainattr, needcheck
+
+ @use_mx_for_dates
+ def get_value(self, name):
+ try:
+ value = self[name]
+ except KeyError:
+ if not self.has_eid():
+ return None
+ value = self._dbmodel.get('s_'+name)
+ if value is not None:
+ if isinstance(value, Text):
+ value = unicode(value)
+ elif isinstance(value, Blob):
+ value = Binary(str(value))
+ self[name] = value
+ return value
+
+ def has_eid(self):
+ if self.eid is None:
+ return False
+ try:
+ Key(self.eid)
+ return True
+ except BadKeyError:
+ return False
+
+ def complete(self, skip_bytes=True):
+ pass
+
+ def unrelated(self, rtype, targettype, role='subject', limit=None,
+ ordermethod=None):
+ # XXX dumb implementation
+ if limit is not None:
+ objs = Query(str(targettype)).Get(limit)
+ else:
+ objs = Query(str(targettype)).Run()
+ return rset_from_objs(self.req, objs, ('eid',),
+ 'Any X WHERE X is %s' % targettype)
+
+ def key(self):
+ return Key(self.eid)
+
+ def put(self, req=None):
+ if req is not None and self.req is None:
+ self.req = req
+ dbmodel = self.to_gae_model()
+ key = Put(dbmodel)
+ self.set_eid(str(key))
+ if self.req is not None and self.rset is None:
+ self.rset = rset_from_objs(self.req, dbmodel, ('eid',),
+ 'Any X WHERE X eid %(x)s', {'x': self.eid})
+ self.row = self.col = 0
+ return dbmodel
+
+ @needrequest
+ def get(cls, req, keys):
+ # if check if this is a dict.key call
+ if isinstance(cls, Model) and keys in cls._attributes:
+ return super(Model, cls).get(keys)
+ rset = rset_from_objs(req, Get(keys), ('eid',),
+ 'Any X WHERE X eid IN %(x)s', {'x': keys})
+ return list(rset.entities())
+
+ @needrequest
+ def get_by_id(cls, req, ids, parent=None):
+ if isinstance(parent, Model):
+ parent = parent.key()
+ ids, multiple = NormalizeAndTypeCheck(ids, (int, long))
+ keys = [Key.from_path(cls.kind(), id, parent=parent)
+ for id in ids]
+ rset = rset_from_objs(req, Get(keys))
+ return list(rset.entities())
+
+ @classmethod
+ def get_by_key_name(cls, req, key_names, parent=None):
+ if isinstance(parent, Model):
+ parent = parent.key()
+ key_names, multiple = NormalizeAndTypeCheck(key_names, basestring)
+ keys = [Key.from_path(cls.kind(), name, parent=parent)
+ for name in key_names]
+ rset = rset_from_objs(req, Get(keys))
+ return list(rset.entities())
+
+ @classmethod
+ def get_or_insert(cls, req, key_name, **kwds):
+ def txn():
+ entity = cls.get_by_key_name(key_name, parent=kwds.get('parent'))
+ if entity is None:
+ entity = cls(key_name=key_name, **kwds)
+ entity.put()
+ return entity
+ return RunInTransaction(txn)
+
+ @classmethod
+ def all(cls, req):
+ rset = rset_from_objs(req, Query(cls.id).Run())
+ return list(rset.entities())
+
+ @classmethod
+ def gql(cls, req, query_string, *args, **kwds):
+ raise NotImplementedError('use rql')
+
+ @classmethod
+ def kind(cls):
+ return self.id
+
+ @classmethod
+ def properties(cls):
+ raise NotImplementedError('use eschema')
+
+ def dynamic_properties(self):
+ raise NotImplementedError('use eschema')
+
+ def is_saved(self):
+ return self.has_eid()
+
+ def parent(self):
+ parent = self._dbmodel.parent()
+ if not parent is None:
+ rset = rset_from_objs(self.req, (parent,), ('eid',),
+ 'Any X WHERE X eid %(x)s', {'x': parent.key()})
+ parent = rset.get_entity(0, 0)
+ return parent
+
+ def parent_key(self):
+ return self.parent().key()
+
+ def to_xml(self):
+ return self._dbmodel.ToXml()
+
+# hijack AnyEntity class
+entities.AnyEntity = Model
+
+BooleanProperty = db.BooleanProperty
+URLProperty = db.URLProperty
+DateProperty = db.DateProperty
+DateTimeProperty = db.DateTimeProperty
+TimeProperty = db.TimeProperty
+StringProperty = db.StringProperty
+TextProperty = db.TextProperty
+BlobProperty = db.BlobProperty
+IntegerProperty = db.IntegerProperty
+FloatProperty = db.FloatProperty
+ListProperty = db.ListProperty
+SelfReferenceProperty = db.SelfReferenceProperty
+UserProperty = db.UserProperty
+
+
+class ReferencePropertyStub(object):
+ def __init__(self, cls, args, kwargs):
+ self.cls = cls
+ self.args = args
+ self.kwargs = kwargs
+ self.required = False
+ self.__dict__.update(kwargs)
+ self.creation_counter = db.Property.creation_counter
+ db.Property.creation_counter += 1
+
+ @property
+ def data_type(self):
+ class FakeDataType(object):
+ @staticmethod
+ def kind():
+ return self.cls.__name__
+ return FakeDataType
+
+def ReferenceProperty(cls, *args, **kwargs):
+ if issubclass(cls, db.Model):
+ cls = db.class_for_kind(cls.__name__)
+ return db.ReferenceProperty(cls, *args, **kwargs)
+ return ReferencePropertyStub(cls, args, kwargs)