app/django/core/serializers/json.py
author Sverre Rabbelier <srabbelier@gmail.com>
Sat, 22 Nov 2008 14:53:23 +0000
changeset 555 3cdfb42d941b
parent 323 ff1a9aa48cfd
permissions -rw-r--r--
Split the list view code up in three pieces 1. getListContents which returns the required contents dictionary 2. _list which returns the response for a specified list of contents 3. list which constructs just one content dict and passes it to _list This way it is easier to do step 1 and 2 in other code than list(), which makes it possible to display multiple list pages (by calling getListContents multiple times and passing the result to _list).

"""
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