class JSONField(models.TextField):

    """

    A field for storing JSON-encoded data. The data is accessible as standard

    Python data types and is transparently encoded/decoded to/from a JSON

    string in the database.

    """

    def __init__(self, verbose_name=None, name=None,

                 encoder=DjangoJSONEncoder(), **kwargs):

        models.TextField.__init__(self, verbose_name, name, blank=True,

                                  **kwargs)

        self.encoder = encoder

    def db_type(self):

        return "text"

    def contribute_to_class(self, cls, name):

        def get_json(model_instance):

            return self.dumps(getattr(model_instance, self.attname, None))

        def set_json(model_instance, json):

            setattr(instance, self.attname, self.loads(json))

        super(JSONField, self).contribute_to_class(cls, name)

        setattr(cls, "get_%s_json" % self.name, get_json)

        setattr(cls, "set_%s_json" % self.name, set_json)

        dispatcher.connect(self.post_init, signal=models.signals.post_init,

                           sender=cls)

    def pre_save(self, model_instance, add):

        return self.dumps(getattr(model_instance, self.attname, None))

    def post_init(self, instance=None):

        value = self.value_from_object(instance)

        if value:

            value = self.loads(value)

        else:

            value = {}

        setattr(instance, self.attname, value)

    def dumps(self, data):

        return self.encoder.encode(data)

    def loads(self, s):