Google APIs OAuth in Django
Making an authentication system with google sign-in is a relatively simpler task to do. It can be easily done using Firebase authentication. But the problem comes when we need to access Google APIs of our users such as Google Calendar, Gmail, Drive etc. The main problem is getting the user tokens and storing them. So, that our application can access the Google APIs of the user once they've granted the access and not asking them to authenticate again and again.
So, here is how you can integrate Google OAuth with your Django application and retrieve, store the user tokens. Which can be used to create authenticated requests to Google APIs through
In this article, I am going to show you how you can integrate Google OAuth with your Django application and store the user tokens for future use, accessing the Upcoming Events in the user's Google Calendar using the stored credentials.
I'm going to assume that you've already created a project in Google API Console, enabled the Google Calendar API for your project, setup an OAuth consent screen and you have a
I'm also assuming that you have already initialized a django application.
First of all, you need to install
google-apis-oauth-django to setup oauth and
google-api-python-client to access Google APIs using the following command.
pip install google-apis-oauth-django google-api-python-client
First of all create a
Sign In With Google button that redirects users to an url say
google_oauth/redirect/. First you need to create a view for redirecting users. In your
views.py add the following code.
import os import google_apis_oauth from django.shortcuts import HttpResponseRedirect # The url where the google oauth should redirect # after a successful login. REDIRECT_URI = 'http://localhost:8000/google_oauth/callback/' # Authorization scopes required SCOPES = ['https://www.googleapis.com/auth/calendar'] # Path of the "client_id.json" file JSON_FILEPATH = os.path.join(os.getcwd(), 'client_id.json') def RedirectOauthView(request): oauth_url = google_apis_oauth.get_authorization_url( JSON_FILEPATH, SCOPES, REDIRECT_URI) return HttpResponseRedirect(oauth_url)
Now in your
urls.py, You can include this view by doing something like
urlpatterns = [ ..., path('google_oauth/redirect/', RedirectOauthView) ]
Now when a user clicks on that
Sign In With Google button they would be redirected to a google oauth screen. After a successful login they would be redirected to the
REDIRECT_URI that we have specified above i.e.
So, we need to write a view for that as well. In that view we can now successfully retreive the user credentials as they are successfully authenticated by doing something like this.
def CallbackView(request): try: # Get user credentials credentials = google_apis_oauth.get_crendentials_from_callback( request, JSON_FILEPATH, SCOPES, REDIRECT_URI ) # Stringify credentials for storing them in the DB stringified_token = google_apis_oauth.stringify_credentials( credentials) # Store the credentials safely in the DB ... # Now that you have stored the user credentials you # can redirect user to your main application. ... except exceptions.InvalidLoginException: # This exception is raised when there is an inavlid # request to this callback uri.
Adding this view in the
urlpatterns = [ ..., path('google_oauth/callback/', CallbackView) ]
Now, as you have the user's credentials. You can access the Google APIs by the following method.
import google_apis_oauth from googleapiclient.discovery import build # Load the stored credentials in a variable say 'stringigied_token' # Load the credentials object using the stringified token. creds = google_apis_oauth.load_credentials(stringified_token) # Using credentials to access Upcoming Events service = build('calendar', 'v3', credentials=creds) now = datetime.datetime.utcnow().isoformat() + 'Z' print('Getting the upcoming 10 events') events_result = service.events().list( calendarId='primary', timeMin=now, maxResults=10, singleEvents=True, orderBy='startTime').execute() events = events_result.get('items', ) if not events: print('No upcoming events found.') for event in events: start = event['start'].get('dateTime', event['start'].get('date')) print(start, event['summary'])
That's it! Similarly you can use these credentials to access other Google APIs as well.