Implement Google GIS for web.

[axi]

This is probably a "work in progress".
I'm able to login but:

• I'm not using grantOfflineAccess anymore and I don't know the impacts
• Scope is not used anymore as the "authentication only" functionnality does not need it, again, not sure of the impacts
• I added a third party library (jose) to decode JWT (I just picked one), not sure it the right thing to do (probably not)
• I didn't update changelog nor readme

Let me know

[axi]

The #202 and #231 issues should know about that

[reslear]

please use prettier for format

[reslear]

thx for contributing :)

you use Implicit flow or Authorization code flow ?

[axi]

It looks like google implemented a system different from the oauth2 we knows.
I think it's named One Tap JS.
I used this documentation & that one.

I did try earlier with Implicit flow following this and using requestAccessToken(). I was getting a Bearer I could use in next requests but didn't find a way to get user informations that way

[reslear]

we need use https://developers.google.com/identity/oauth2/web/guides/use-code-model
and then create simple request like oauth to get user

ok, need investigate but many users use Code flow

[axi]

Authorisation Code Flow require a backend endpoint ("Your backend platform hosts an authorization code endpoint and receives the code"), I'm not sure that's what we want, is it ?

[axi]

As written here

Several scopes are used only for user authentication: email, profile, and openid. If your app only uses these scopes, consider if a JWT ID Token and Sign In With Google for user sign-up and sign-in meets your needs. In most cases, this is the most straightforward and simple method available for user authentication.

There are simpler ways to handle authentication if we only need email, profile and openid scopes

[reslear]

maybe there are two ways to implement

[axi]

Sure.
Who can decide which implementation is needed ?
Does someone already use this plugin with other scopes than email profile openid ? If the answer is maybe, then it should still be the case after this (and my current implementation is wrong)

[axi]

I worked on a new version using implicit workflow, supporting scopes. I'll share it tomorrow

[axi]

Probably #259 is better