Flask 3LO helper

[theacodes]

This should fix #224 once merged.

Currently rough and looking for feedback. This intentionally deviates from the appengine/webapp2 decorator to be more idiomatic for flask users.

1. The credentials are currently only stored on the session. I'd like some feedback on how to allow the user to specify storage, and how the session storage should fix into that (should it store both in the session and within the user provided storage?)
2. I'm aware that it doesn't quite fit with the style of the rest of the codebase, I'll adjust to 2 spaces etc before merge.
3. The scopes default to 'email' and 'profile', and there's a mechanism to fetch the user's full profile from google+. I can remove this if we feel it's bloated (users can easily add it back via authorize_callback).

Tests will be added once I validate this approach.

[elibixby]

Looks great!

First thoughts:

I like configurable defaults. Specifically, you might want to to be able to do something like

    @app.route('/login/<custom_return_path>')
    @oauth2.required(scopes=['email', 'somethingelse'], return=custom_return_path)
    def login():
         # Do stuff

Which would make it really easy to implement e.g. a login widget that you throw on every page, but lands you on a specific page (not necesarily the same one) based on where you logged in.

[dhermes]

Change flask.py to something else, like flask_util.py or similar?

[theacodes]

@anthmgoogle modified so that state is now json and stores the return url there to bring it in-line with your recommendations. I still need your feedback on the scopes parameter for incremental auth.

[nathanielmanistaatgoogle]

LGTM; @anthmgoogle will also review.

[theacodes]

Thanks, @nathanielmanistaatgoogle and @dhermes for the thorough review. 👍

[anthmgoogle]

Finished a review pass. A could of comments related to the public surface.

[theacodes]

@anthmgoogle Alright, that should do it. Can you take a final look?

[anthmgoogle]

LGTM.

[dhermes]

I have merge privileges. @jonparrott did you get everyone's sign off?

[theacodes]

We have you, @nathanielmanistaatgoogle and @anthmgoogle. That's everyone.

Thanks, everyone! 🎆

[dhermes]

Wow. The saga is over!