app/django/core/serializers/json.py
author Lennard de Rijk <ljvderijk@gmail.com>
Tue, 14 Jul 2009 18:35:20 +0200
changeset 2647 69ac7307bb50
parent 323 ff1a9aa48cfd
permissions -rw-r--r--
Added task to send out email for each processed GradingRecord. If send_mail evaluates to True in the POST data for updateProjectsForSurveyGroup task then the results of every GradingRecord will be mailed to the Student. The Mentor and Org Admins will be cc'ed.

"""
Serialize data to/from JSON
"""

import datetime
from StringIO import StringIO

from django.core.serializers.python import Serializer as PythonSerializer
from django.core.serializers.python import Deserializer as PythonDeserializer
from django.utils import datetime_safe
from django.utils import simplejson

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):
            d = datetime_safe.new_datetime(o)
            return d.strftime("%s %s" % (self.DATE_FORMAT, self.TIME_FORMAT))
        elif isinstance(o, datetime.date):
            d = datetime_safe.new_date(o)
            return d.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