Facebook authentification with omniauth

Question

I'm encountering an issue with this tutorial to write a Facebook authentification system.

First, I had an error ActiveModel::ForbiddenAttributesError. I corrected it with coderhs answer.

Now when I log in with Facebook it works, but when I log in with annother account, it overwrites the previous user in my table, so I can't have more than one Facebook user connected at the same time and still keep user information about them.

User.rb

def self.from_omniauth(auth)
    where(auth.slice(provider: auth.provider, uid: auth.uid)).first_or_create.tap do |user|
        user.provider ||= auth.provider
        user.uid = auth.uid
        user.name = auth.info.name
        user.oauth_token = auth.credentials.token
        user.oauth_expires_at = Time.at(auth.credentials.expires_at)
        user.save!
    end

EDIT I noticed first_or_create edit the last query inserted and do not create entry, i added it:

User.rb

def self.from_omniauth(auth)
        where(auth.slice(uid: auth.uid)).first_or_create.tap do |user|
            if user.uid == auth.uid
                puts "\nUserModel:_________" + auth.provider + " - " + auth.uid + "\n"
            else
                puts "\nUnknown user        " + auth.uid
            end
            user.provider = auth.provider
            user.uid = auth.uid
            user.name = auth.info.name
            user.email = auth.info.email
            user.oauth_token = auth.credentials.token
            user.oauth_expires_at = Time.at(auth.credentials.expires_at)
            user.save
        end
    end

When i sign-in with a 2nd account, the else puts is displayed in the console but it edit and not create a new row in the table

Edit2 [Solution]

User.rb

def self.from_omniauth(auth)
        User.find_or_create_by(uid: auth.uid).tap do |user|
            if user.uid == auth.uid
                puts "\nUserModel:_________" + auth.provider + " - " + auth.uid + "\n"
            else
                puts "\nUnknown user        " + auth.uid
            end
            user.provider = auth.provider
            user.uid = auth.uid
            user.name = auth.info.name
            user.email = auth.info.email
            user.oauth_token = auth.credentials.token
            user.oauth_expires_at = Time.at(auth.credentials.expires_at)
            user.save
        end
    end

[Second question solved by Oleksandr Avoyants]I also want to know how to get the email from the Facebook user. I tried to add

user.email = auth.email

...but it was too easy to be true.

Answer 1

According to omniauth-facebook README you can get user's email with:

auth.info.email

NOTE: The precise information available may depend on the permissions which you request.