resources.py 文件源码

def error_response(self, request, errors, response_class=None):
        """
        Extracts the common "which-format/serialize/return-error-response"
        cycle.

        Should be used as much as possible to return errors.
        """
        if response_class is None:
            response_class = http.HttpBadRequest

        desired_format = None

        if request:
            if request.GET.get('callback', None) is None:
                try:
                    desired_format = self.determine_format(request)
                except BadRequest:
                    pass  # Fall through to default handler below
            else:
                # JSONP can cause extra breakage.
                desired_format = 'application/json'

        if not desired_format:
            desired_format = self._meta.default_format

        try:
            serialized = self.serialize(request, errors, desired_format)
        except BadRequest, e:
            error = "Additional errors occurred, but serialization of those errors failed."

            if settings.DEBUG:
                error += " %s" % e

            return response_class(content=error, content_type='text/plain')

        return response_class(content=serialized, content_type=build_content_type(desired_format))