mirror of
https://github.com/encode/django-rest-framework.git
synced 2024-11-26 11:33:59 +03:00
75 lines
2.9 KiB
Python
75 lines
2.9 KiB
Python
|
from rest_framework import exceptions
|
||
|
|
from rest_framework.settings import api_settings
|
||
|
|
from rest_framework.utils.mediatypes import order_by_precedence
|
||
|
|
|
||
|
|
|
||
|
|
class BaseContentNegotiation(object):
|
||
|
|
def negotiate(self, request, renderers, format=None, force=False):
|
||
|
|
raise NotImplementedError('.negotiate() must be implemented')
|
||
|
|
|
||
|
|
|
||
|
|
class DefaultContentNegotiation(object):
|
||
|
|
settings = api_settings
|
||
|
|
|
||
|
|
def negotiate(self, request, renderers, format=None, force=False):
|
||
|
|
"""
|
||
|
|
Given a request and a list of renderers, return a two-tuple of:
|
||
|
|
(renderer, media type).
|
||
|
|
|
||
|
|
If force is set, then suppress exceptions, and forcibly return a
|
||
|
|
fallback renderer and media_type.
|
||
|
|
"""
|
||
|
|
try:
|
||
|
|
return self.unforced_negotiate(request, renderers, format)
|
||
|
|
except (exceptions.InvalidFormat, exceptions.NotAcceptable):
|
||
|
|
if force:
|
||
|
|
return (renderers[0], renderers[0].media_type)
|
||
|
|
raise
|
||
|
|
|
||
|
|
def unforced_negotiate(self, request, renderers, format=None):
|
||
|
|
"""
|
||
|
|
As `.negotiate()`, but does not take the optional `force` agument,
|
||
|
|
or suppress exceptions.
|
||
|
|
"""
|
||
|
|
# Allow URL style format override. eg. "?format=json
|
||
|
|
format = format or request.GET.get(self.settings.URL_FORMAT_OVERRIDE)
|
||
|
|
|
||
|
|
if format:
|
||
|
|
renderers = self.filter_renderers(renderers, format)
|
||
|
|
|
||
|
|
accepts = self.get_accept_list(request)
|
||
|
|
|
||
|
|
# Check the acceptable media types against each renderer,
|
||
|
|
# attempting more specific media types first
|
||
|
|
# NB. The inner loop here isn't as bad as it first looks :)
|
||
|
|
# Worst case is we're looping over len(accept_list) * len(self.renderers)
|
||
|
|
for media_type_set in order_by_precedence(accepts):
|
||
|
|
for renderer in renderers:
|
||
|
|
for media_type in media_type_set:
|
||
|
|
if renderer.can_handle_media_type(media_type):
|
||
|
|
return renderer, media_type
|
||
|
|
|
||
|
|
raise exceptions.NotAcceptable(available_renderers=renderers)
|
||
|
|
|
||
|
|
def filter_renderers(self, renderers, format):
|
||
|
|
"""
|
||
|
|
If there is a '.json' style format suffix, filter the renderers
|
||
|
|
so that we only negotiation against those that accept that format.
|
||
|
|
"""
|
||
|
|
renderers = [renderer for renderer in renderers
|
||
|
|
if renderer.can_handle_format(format)]
|
||
|
|
if not renderers:
|
||
|
|
raise exceptions.InvalidFormat(format)
|
||
|
|
return renderers
|
||
|
|
|
||
|
|
def get_accept_list(self, request):
|
||
|
|
"""
|
||
|
|
Given the incoming request, return a tokenised list of media
|
||
|
|
type strings.
|
||
|
|
|
||
|
|
Allows URL style accept override. eg. "?accept=application/json"
|
||
|
|
"""
|
||
|
|
header = request.META.get('HTTP_ACCEPT', '*/*')
|
||
|
|
header = request.GET.get(self.settings.URL_ACCEPT_OVERRIDE, header)
|
||
|
|
return [token.strip() for token in header.split(',')]
|