Python example using refresh token to update access token for Mendeley API using the Mendeley Python SDK

auto-refresh-mendeley-token.py

from mendeley import Mendeley
from mendeley.exception import MendeleyException
from mendeley.session import MendeleySession

# extending the MendeleySession class to do auto-token-refresh on 
# token expiration. Mendeley access tokens expire after 1 hour.
class AutoRefreshMendeleySession(MendeleySession):
    def __init__(self, mendeley, token, refresh_token):
        super(AutoRefreshMendeleySession, self).__init__(mendeley, token)
        # silly name to avoid namespace collision with oauth refresh_token() method
        self.the_refresh_token = refresh_token
        self.client_secret = mendeley.client_secret

    def request(self, method, url, data=None, headers=None, **kwargs):
        try:
            # just try the MendeleySession request first
            return super(AutoRefreshMendeleySession, self).request(method, url, data, headers, **kwargs)
        except (MendeleyApiException, TokenExpiredError) as e:
            print ("Receiving " + type(e).__name__)
            # Check to see if we have an expired access token. This comes in two
            # forms: either a MendeleyApiException or OAuthlib's TokenExpiredError
            #
            # Mendeley's API uses MendeleyAPIException for everything so you have
            # to unpack it and inspect to see if it's a token expiration or not.
            # In event of an expired token it sends back a 401 with the JSON message
            # {"message": "Could not access resource because: Token has expired"}
            # and the Python SDK forms a MendeleyAPIException with this message
            # in e.message and 401 in e.status
            # OAuthlib will send a TokenExpiredError if you have a long-running
            # session that goes over an hour. MendeleyApiException occurs when 
            # you try to make a first request with an already expired token (such
            # as the one that's probably in your app's config file.)
            if ((type(e).__name__ is 'MendeleyApiException') and (e.status == 401) and ('Token has expired' in e.message)) or (type(e).__name__ is 'TokenExpiredError'):
                print ("Handling a token expiration of type " + type(e).__name__)
                self.refresh_token('https://api.mendeley.com/oauth/token', self.the_refresh_token, auth=(self.client_id, self.client_secret), redirect_uri="www.ipums.org")
                return super(AutoRefreshMendeleySession, self).request(method, url, data, headers, **kwargs)
            else:
                print ("Re-raising " + type(e).__name__)
                # pass on other mendeley exceptions
                raise
# example use
mendeley = Mendeley(CLIENT_ID, CLIENT_SECRET)
session = AutoRefreshMendeleySession(mendeley,{'access_token': ACCESS_TOKEN, 'token_type': "Bearer"}, REFRESH_TOKEN)
# This will call the API, refreshing the token if needed
for document in session.documents.iter():
    print (document.title)