Synnefo

# vim: ts=4 sts=4 et ai sw=4 fileencoding=utf-8

#

# Copyright © 2010 Greek Research and Technology Network

#

from piston.resource import Resource as BaseResource

from synnefo.helpers import parse_accept_header

import synnefo.api.emitter # load our own Emitter

class Resource(BaseResource):

    def determine_emitter(self, request, *args, **kwargs):

        """

        Override default emitter policy to account for Accept header

        emitter_format (.json or .xml suffix in URL) always takes precedence.

        After that, the Accept header is checked; if both JSON and XML are

        equally preferred, use JSON.

        If none of the two were provided, then use JSON as per the

        specification.

        """

        em = request.GET.get('format', 'json')

        if 'emitter_format' in kwargs and \

           kwargs["emitter_format"] is not None:

            em = kwargs.pop('emitter_format')

        elif 'HTTP_ACCEPT' in request.META:

            accepts = parse_accept_header(request.META['HTTP_ACCEPT'])

            for content_type, quality in accepts:

                if content_type == 'application/json':

                    break

                elif content_type == 'application/xml':

                    em = request.GET.get('format', 'xml')

                    break

        return em