Add ModelWithFieldAttributes *before* PolyModel, so that everything does not
become a "ModelWithFieldAttributes" in the Datastore.
The way PolyModel works, each Model class hierarchy is stored in the Datastore
as the class that directly inherited from PolyModel. So, we do not want to
insert ModelWithFieldAttributes *after* PolyModel by inheriting *from*
PolyModel, or everything would just be a ModelWithFieldAttributes in the
Datastore, instead of Person, Work, Group, etc.
"""
Serialize data to/from JSON
"""
import datetime
from django.utils import simplejson
from django.core.serializers.python import Serializer as PythonSerializer
from django.core.serializers.python import Deserializer as PythonDeserializer
try:
from cStringIO import StringIO
except ImportError:
from StringIO import StringIO
try:
import decimal
except ImportError:
from django.utils import _decimal as decimal # Python 2.3 fallback
class Serializer(PythonSerializer):
"""
Convert a queryset to JSON.
"""
internal_use_only = False
def end_serialization(self):
self.options.pop('stream', None)
self.options.pop('fields', None)
simplejson.dump(self.objects, self.stream, cls=DjangoJSONEncoder, **self.options)
def getvalue(self):
if callable(getattr(self.stream, 'getvalue', None)):
return self.stream.getvalue()
def Deserializer(stream_or_string, **options):
"""
Deserialize a stream or string of JSON data.
"""
if isinstance(stream_or_string, basestring):
stream = StringIO(stream_or_string)
else:
stream = stream_or_string
for obj in PythonDeserializer(simplejson.load(stream)):
yield obj
class DjangoJSONEncoder(simplejson.JSONEncoder):
"""
JSONEncoder subclass that knows how to encode date/time and decimal types.
"""
DATE_FORMAT = "%Y-%m-%d"
TIME_FORMAT = "%H:%M:%S"
def default(self, o):
if isinstance(o, datetime.datetime):
return o.strftime("%s %s" % (self.DATE_FORMAT, self.TIME_FORMAT))
elif isinstance(o, datetime.date):
return o.strftime(self.DATE_FORMAT)
elif isinstance(o, datetime.time):
return o.strftime(self.TIME_FORMAT)
elif isinstance(o, decimal.Decimal):
return str(o)
else:
return super(DjangoJSONEncoder, self).default(o)
# Older, deprecated class name (for backwards compatibility purposes).
DateTimeAwareJSONEncoder = DjangoJSONEncoder