app/django/core/serializers/pyyaml.py
author Lennard de Rijk <ljvderijk@gmail.com>
Fri, 23 Jan 2009 12:00:48 +0000
changeset 920 39badbfb80be
parent 323 ff1a9aa48cfd
permissions -rw-r--r--
Added the new way to process invites for club_admin only. This patch contains the separability needed to ensure that we can successfully do the access checks we need. Host invites can for the time being only be completed by developers due to the reorganization. Patch by: Lennard de Rijk Reviewed by: to-be-reviewed

"""
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