CODEWITHSUNDEEP
pythongoogle-app-engineoauth-2.0google-oauth
minou
minou

Reputation: 16573

GAE: converting users from users service to oauth2

I currently use the "Google Accounts API" to allow users to login to my GAE app. So I use users.create_login_url and users.get_current_user and add an ndb.UserProperty to my own user entity so that I can retrieve data for that user.

I'm now in the process of switching to oauth2 (using authomatic).

I need to convert all of my existing user accounts to oauth2 and I'd like to make this as easy as possible for my users. This is my current plan:

  1. Change the login from users service to oauth2.

  2. After the user logs in, it will look like a new account and the user will not see his or her previous data.

  3. I'll add a prominent message asking the user to login with the old users service.

  4. I'll then merge the old users service account with the oauth2 account.

This should work, but it will be a little confusing for the users. Is there a better way of doing this?

Upvotes: 0

Views: 64

Answers (1)

minou
minou

Reputation: 16573

I'll explain how I ended up doing this in case it helps others.

I call my users managers and I have a Manager entity for each user:

class Manager(ndb.Model):
    user_account = ndb.StructuredProperty(UserAccount))
    linked = ndb.BooleanProperty(default=False)
    user = ndb.UserProperty()

The user property is the old users service account that I will get rid of. The user_account property stores info to identify the Oauth2 account: 

class UserAccount(ndb.Model):
    provider = ndb.StringProperty(required=True)
    id = ndb.StringProperty(required=True)
    name = ndb.StringProperty()
    email = ndb.StringProperty()

Essentially, for each manager, I want to set a value for user_account (Oauth2 login) and remove user (old user account). I want to do this with minimum burden on the manager.

When the user has recently logged in under the old user account, that cookie will sill be active. Now, however, the user is logging in with an Oauth2 account. After logging in with Oauth2, we check to see if the old user account cookie is still active. If so, we merge the accounts automatically. Here is a sketch of the handler.

class ManagerPage(webapp2.RequestHandler):

    def get(self):

        # This returns a Manager entity after the user has logged in with
        # Oauth2. If the user is logging in for the first time, this will
        # be a blank Manager entity.
        self.get_manager()

        # Temporary processing to link accounts.  If the user is still logged
        # as a Google user (because that cookie hasn't expired), then we  
        # automatically transfer their old information to the new Manager 
        # entity.  In doing the conversion below, manager.linked is set to
        # True so this can't happen more than once.  Now that the Manager
        # entity has been updated, redirect back to the same page.
        gae_user = users.get_current_user()
        if not manager.linked and gae_user:
            manager.convert_old_manager(gae_user)
            self.redirect("/manager")

        # Present info to the manager
        ...
        template = JINJA_ENVIRONMENT.get_template("manager.html")
        self.response.write(template.render(template_values))

If the old user account cookie is not active, then I have a link in the above manager page that asks the user to link the old account with the new account. When the user logs in with the old account, they are redirected to the above Manager Page, and the account is automatically linked.

Upvotes: 1

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