app/django/core/serializers/pyyaml.py
author Sverre Rabbelier <srabbelier@gmail.com>
Sat, 13 Dec 2008 12:49:11 +0000
changeset 729 7fe218e3d359
parent 323 ff1a9aa48cfd
permissions -rw-r--r--
Make checkIsMyInvitation use Django to parse the URL Using django is more reliable and makes the code easier to read as there is no knowledge of the url layout required. Patch by: Sverre Rabbelier

"""
YAML serializer.

Requires PyYaml (http://pyyaml.org/), but that's checked for in __init__.
"""

from StringIO import StringIO
import yaml

from django.db import models
from django.core.serializers.python import Serializer as PythonSerializer
from django.core.serializers.python import Deserializer as PythonDeserializer

class Serializer(PythonSerializer):
    """
    Convert a queryset to YAML.
    """
    
    internal_use_only = False
    
    def handle_field(self, obj, field):
        # A nasty special case: base YAML doesn't support serialization of time
        # types (as opposed to dates or datetimes, which it does support). Since
        # we want to use the "safe" serializer for better interoperability, we
        # need to do something with those pesky times. Converting 'em to strings
        # isn't perfect, but it's better than a "!!python/time" type which would
        # halt deserialization under any other language.
        if isinstance(field, models.TimeField) and getattr(obj, field.name) is not None:
            self._current[field.name] = str(getattr(obj, field.name))
        else:
            super(Serializer, self).handle_field(obj, field)
    
    def end_serialization(self):
        self.options.pop('stream', None)
        self.options.pop('fields', None)
        yaml.safe_dump(self.objects, self.stream, **self.options)

    def getvalue(self):
        return self.stream.getvalue()

def Deserializer(stream_or_string, **options):
    """
    Deserialize a stream or string of YAML data.
    """
    if isinstance(stream_or_string, basestring):
        stream = StringIO(stream_or_string)
    else:
        stream = stream_or_string
    for obj in PythonDeserializer(yaml.load(stream)):
        yield obj