Source code for oauth_dropins.medium

"""Medium OAuth drop-in.

API docs:
https://github.com/Medium/medium-api-docs#contents
https://medium.com/developers/welcome-to-the-medium-api-3418f956552

Medium doesn't let you use a localhost redirect URL. : / A common workaround is
to map an arbitrary host to localhost in your /etc/hosts, e.g.:

127.0.0.1 my.dev.com

You can then test on your local machine by running dev_appserver and opening
http://my.dev.com:8080/ instead of http://localhost:8080/ .
"""

import json
import logging
import urllib

import appengine_config
import handlers
from models import BaseAuth
from webutil import util

from google.appengine.ext import ndb
from webob import exc

# medium is behind cloudflare, which often blocks requests's user agent, so set
# our own.
USER_AGENT = 'oauth-dropins (https://oauth-dropins.appspot.com/)'

# URL templates. Can't (easily) use urllib.urlencode() because I want to keep
# the %(...)s placeholders as is and fill them in later in code.
GET_AUTH_CODE_URL = str('&'.join((
    'https://medium.com/m/oauth/authorize?'
    'client_id=%(client_id)s',
    # https://github.com/Medium/medium-api-docs#user-content-21-browser-based-authentication
    # basicProfile, listPublications, publishPost, uploadImage
    'scope=%(scope)s',
    # redirect_uri here must be the same in the access token request!
    'redirect_uri=%(redirect_uri)s',
    'state=%(state)s',
    'response_type=code',
    )))

API_BASE = 'https://api.medium.com/v1/'
GET_ACCESS_TOKEN_URL = API_BASE + 'tokens'
API_USER_URL = API_BASE + 'me'


[docs]class MediumAuth(BaseAuth): """An authenticated Medium user. Provides methods that return information about this user and make OAuth-signed requests to the Medium REST API. Stores OAuth credentials in the datastore. See models.BaseAuth for usage details. Medium-specific details: implements get() but not urlopen(), http(), or api(). The key name is the user id (*not* username). """ access_token_str = ndb.StringProperty(required=True) user_json = ndb.TextProperty() # used by bridgy in # https://github.com/snarfed/bridgy/commit/58cce60790e746d300e7e5dac331543c56bd9108 # background: https://github.com/snarfed/bridgy/issues/506 publications_json = ndb.TextProperty()
[docs] def site_name(self): return 'Medium'
[docs] def user_display_name(self): """Returns the user's full name or username. """ if self.user_json: data = json.loads(self.user_json).get('data') if data: return data.get('name') or data.get('username') return self.key.string_id()
[docs] def access_token(self): """Returns the OAuth access token string. """ return self.access_token_str
[docs] def get(self, *args, **kwargs): """Wraps requests.get() and adds the Bearer token header. """ headers = kwargs.setdefault('headers', {}) headers['Authorization'] = 'Bearer ' + self.access_token_str headers.setdefault('User-Agent', USER_AGENT) resp = util.requests_get(*args, **kwargs) try: resp.raise_for_status() except BaseException, e: util.interpret_http_exception(e) raise return resp
[docs]class StartHandler(handlers.StartHandler): """Starts Medium auth. Requests an auth code and expects a redirect back. """ DEFAULT_SCOPE = 'basicProfile'
[docs] def redirect_url(self, state=None): assert (appengine_config.MEDIUM_CLIENT_ID and appengine_config.MEDIUM_CLIENT_SECRET), ( "Please fill in the medium_client_id and " "medium_client_secret files in your app's root directory.") return str(GET_AUTH_CODE_URL % { 'client_id': appengine_config.MEDIUM_CLIENT_ID, 'redirect_uri': urllib.quote_plus(self.to_url()), # Medium requires non-empty state 'state': urllib.quote_plus(state if state else 'unused'), 'scope': self.scope, })
[docs]class CallbackHandler(handlers.CallbackHandler): """The OAuth callback. Fetches an access token and stores it. """ def get(self): # handle errors error = self.request.get('error') if error: if error == 'access_denied': logging.info('User declined') self.finish(None, state=self.request.get('state')) return else: raise exc.HTTPBadRequest('Error: %s' % error) # extract auth code and request access token auth_code = util.get_required_param(self, 'code') data = { 'code': auth_code, 'client_id': appengine_config.MEDIUM_CLIENT_ID, 'client_secret': appengine_config.MEDIUM_CLIENT_SECRET, # redirect_uri here must be the same in the oauth code request! # (the value here doesn't actually matter since it's requested server side.) 'redirect_uri': self.request.path_url, 'grant_type': 'authorization_code', } resp = util.requests_post( GET_ACCESS_TOKEN_URL, data=urllib.urlencode(data), headers={'User-Agent': USER_AGENT}).text logging.debug('Access token response: %s', resp) try: resp = json.loads(resp) except: logging.exception('Could not decode JSON') raise errors = resp.get('errors') or resp.get('error') if errors: logging.info('Errors: %s', errors) raise exc.HTTPBadRequest(errors[0].get('message')) # TODO: handle refresh token access_token = resp['access_token'] user_json = MediumAuth(access_token_str=access_token).get(API_USER_URL).text id = json.loads(user_json)['data']['id'] auth = MediumAuth(id=id, access_token_str=access_token, user_json=user_json) auth.put() self.finish(auth, state=self.request.get('state'))