return JSON 认证失败时如何输出？

Question

我正在编写 repoze.who plugin 并希望从 repoze.who 身份验证中间件 return JSON 并且仍然控制 HTTP 状态代码。如何做到这一点？

Answer 1

实现此目的的一种方法是实施 repoze.who Challenger interface. The following solution takes advantage of the fact that the WebOb exceptions, in webob.exc, can be used as a WSGI application. The following example shows how this can be used in a hypothetical Facebook plugin, where the 2.x API 让用户不授予对其电子邮件的访问权限，这可能是成功 registration/authentication:

import json
from webob.acceptparse import MIMEAccept
from webob.exc import HTTPUnauthorized, HTTPBadRequest


FACEBOOK_CONNECT_REPOZE_WHO_NOT_GRANTED = 'repoze.who.facebook_connect.not_granted'


class ExampleJSONChallengerPlugin(object):
    json_content_type = 'application/json'
    mime_candidates = ['text/html',
                       'application/xhtml+xml',
                       json_content_type,
                       'application/xml',
                       'text/xml']

    def is_json_request_env(self, environ):
        """Checks whether the current request is a json request as deemed by
        TurboGears (i.e. response_type is already set) or if the http
        accept header favours 'application/json' over html.
        """
        if environ['PATH_INFO'].endswith('.json'):
            return True

        if 'HTTP_ACCEPT' not in environ:
            return False

        # Try to mimic what Decoration.lookup_template_engine() does.
        return MIMEAccept(environ['HTTP_ACCEPT']) \
            .best_match(self.mime_candidates) is self.json_content_type

    def challenge(self, environ, status, app_headers, forget_headers):
        if FACEBOOK_CONNECT_REPOZE_WHO_NOT_GRANTED in environ:
            response = HTTPBadRequest(detail={
                'not_granted': 
                environ.pop(FACEBOOK_CONNECT_REPOZE_WHO_NOT_GRANTED),
            })
        elif status.startswith('401 '):
            response = HTTPUnauthorized()
        else:
            response = None

        if response is not None and self.is_json_request_env(environ):
            response.body = json.dumps({
                'code': response.code,
                'status': response.title,
                'explanation': response.explanation,
                'detail': response.detail,
            })
            response.content_type = self.json_content_type

        return response

这里的中心点是 response，webob.exc.WSGIHTTPException 的 sub-class 的一个实例，被用作 WSGI 应用程序，而且如果 response' s body 属性被设置，那么它是 not 自动生成的，事实上我们用来显式设置响应的 body 为 JSON-formatted 字符串表示我们的字典。如果在处理对以 '.json' 结尾的 URL 或 Accept header 包含 application/json 的请求期间调用上述挑战者，则 body 的响应可能呈现为：

{
    "status": "Bad Request",
    "explanation": "The server could not comply with the request since it is either malformed or otherwise incorrect.",
    "code": 400, 
    "detail": {"not_granted": ["email"]}
}

如果不是，则 body 将呈现为 HTML:

<html>
 <head>
  <title>400 Bad Request</title>
 </head>
 <body>
  <h1>400 Bad Request</h1>
  The server could not comply with the request since it is either 
  malformed or otherwise incorrect.<br /><br />
{'not_granted': [u'email']}


 </body>
</html>

return JSON 认证失败时如何输出？

How can I return JSON output when repoze.who authentication fails?

python

json

authentication

turbogears2

repoze.who