Other authentication methods

[pbrisbin]

• http://hackage.haskell.org/package/yesod-auth-1.4.4/docs/Yesod-Auth-GoogleEmail2.html
• https://hackage.haskell.org/package/yesod-auth-fb
• Twitter (we'll write this ourselves in yesod-auth-oauth2)

[pbrisbin]

Adding Twitter to yesod-auth-oauth2: freckle/yesod-auth-oauth2#27

[pbrisbin]

Adding Google to carnival: #212

[pbrisbin]

I'm going to consider this done for now. We won't be adding Twitter since it doesn't provide an Email. If folks feels strongly about providing FB, we can add a new issue for it.

[jferris]

It's too bad Twitter is such a pain. I feel like that's the most likely one people will use. Is there a way to get people to "finalize" OAuth2 logins, so that they enter an email after authenticating with Twitter?

Or, could we make email nullable? Is that a bad path to go down?

[pbrisbin]

We could probably add a custom screen to get an email from the user as part of on-boarding. I'm not sure what this'd look like or how difficult it'd be. I'd definitely prefer not to make userEmail a Maybe, but it's not the end of the world if the other options are too complicated. As of now, that would really just mean handling gravatars and notifications differently.