Angularfire Multi Auth

This repo is deprecated since Firebase 3.0 support Link mutiple auth providers out-of-box

The problem

If you wanna use the Signup/Login feature that Firebase brings out of the box (formely Simple Login) you may face one problem: How to handle multiple login provides for the same user?

The solution

From this question on Stack Overflow, Andrew Lee give us a suggestion to accommodate it creating some structure inside Firebase to handle the process. And it is a very good idea. The only problem is the mess you should made on your code to accomplish that.

So, this is the reason I've created angularfire-multi-auth

What is angularfire-multi-auth?

It's a factory decorator for $firebaseAuth that abstract the complexity of creating the structure needed for use multiple login providers for the same user.

How to install it?

You need to install it and add it on your index.html file:

bower install angularfire-multi-auth --save

Install the basic security rule contained on file securityRules.json

And create an Angular Constant calle FBURL_ALTERNATE that should contain the alternative Firebase URL for being used on associateSocial feature.

And you will use Angularfire normally.

How it works?

For every new user created via $createUser or the first time you use $authWithOAuthPopup we will create the following entries on Firebase:

|-authGroup
|-----[authGroupId]
|-----------[user.provider]:[user.uid]
|-userMapping
|-----[user.uid]:[authGroupId]

When you call $associatePassword we will create another Email/Password associating it to the logged user like:

|-authGroup
|-----[authGroupId]
|-----------[user.provider]:[user.uid]
|-----------[NEWuser.provider]:[NEWuser.uid]  <<<<<<<
|-userMapping
|-----[user.uid]:[authGroupId]

We do the same when you use $associateSocial, but for this case we need a little help of FBURL_ALTERNATE constant because we can't call $authWithPopup with a logged user, so we will user an alternative Firebase URL (you can use a free one because it will just be used on exact moment the user is being associated to the current one)

And we also added a authGroup property for the user returned by $getAuth it will make things easier when setting ownership on Firebase data.

Security Usage

Now you should protect entities based on authGroup instead of the uid. To do that you only need to use the following security rule to grab the 'authGroup' of the logged user on Security rules:

root.child('userMapping').child(auth.uid).val()

Project Status

I started it alone, but we are already 3 awesome people building this library:

@douglascorrea

@luanven

@gilhanan

BUT we still really really want and appreciate your help. Let's do this a "many awesome contributors show".

Please go ahead open issues, create PRs and help me build this useful library.

If you want you can ping me on twitter @douglas_correa