Rails OmniAuth snippet

User.rb

  
  def self.create_from_hash(registration_hash)
    unless registration_hash || resigration_hash.empty?
      return nil
    end

    provider = registration_hash[:provider]
    info = registration_hash[:info]
    
    user = User.new
    
    if info.password
      user.password = info.password
    else
      user.password = Devise.friendly_token[0,20]
    end
    user.password_confirmation = user.password
    
    if provider == "seznam" || provider == "open_id"
      user.email = info.nickname
    else
      user.email = info.email
    end
    
    # if data.first_name && info.last_name
    #   user.first_name = info.first_name if user.first_name.blank?
    #   user.last_name  = info.last_name  if user.last_name.blank?
    # elsif data.name
    #   user.full_name  = info.name if user.full_name.blank?
    #   user.first_name = info.name.split(' ')[0] if user.first_name.blank?
    #   user.last_name  = info.name.split(' ')[1] if user.last_name.blank?
    # end

    # twitter: čtverec 48x48; odstranit "_normal" ze stringu pro plnou velikost obrázku
    # facebook: čtverec 50x50; dál už se s tím nic nedá dělat
    # user.image = info.image if user.image.blank?
    
    # user.gender = registration_hash['extra']['gender'] if user.gender.blank?

    if registration_hash[:skip_confirmation] == true
      # user.confirm!
    end

    user
  end

v1.rb

  def process_callback
    registration_hash = @omniauth
    
    # Find if an authentication token for this provider and user id already exists
    authentication = Authentication.find_by_provider_and_uid(@omniauth['provider'], @omniauth['uid'])
    if authentication # We found an authentication
      if user_signed_in? && (authentication.user.id != current_user.id)
        flash[:error] = I18n.t "controllers.omniauth_callbacks.process_callback.error.account_already_taken", 
                               :provider => @omniauth[:provider].capitalize,
                               :account  => @omniauth[:uid] # registration_hash[:email]
        redirect_to edit_user_registration_path(current_user) # edit_user_account_path
        return
      elsif
        flash[:success] = "Signed in successfully."
        sign_in_and_redirect(:user, authentication.user)
      end
      
    else # We could not find the authentication than create one
      authentication = Authentication.new(:provider => @omniauth['provider'], :uid => @omniauth['uid'])
      if user_signed_in?   
        authentication.user = current_user
      else
        registration_hash[:skip_confirmation] = true
        authentication.user = User.find_by_email(registration_hash[:info][:email]) || User.create_from_hash(registration_hash)
      end
    end
    
    @user = authentication.user
    # save the authentication 
    authentication.token    = @omniauth
    authentication.provider = registration_hash[:provider]
    authentication.uemail   = registration_hash[:info][:email]
    authentication.uname    = registration_hash[:info][:name]
    
    if !authentication.save
      logger.error authentication.errors
      logger.debug authentication.to_yaml
      logger.debug @user.to_yaml
    end
    
    # If a user is signed in then he is trying to link a new account
    if user_signed_in?
      if authentication.save # This was a linking operation so send back the user to the account edit page  
        flash[:success] = I18n.t "controllers.omniauth_callbacks.process_callback.success.link_account", 
                                 :provider => @omniauth[:provider].capitalize,
                                 :account  => @omniauth[:uid] # registration_hash[:email]
      else
        flash[:error] = I18n.t "controllers.omniauth_callbacks.process_callback.error.link_account", 
                               :provider => @omniauth[:provider].capitalize,
                               :account  => @omniauth[:uid], # registration_hash[:email]
                               :errors   => authentication.errors
      end  
      redirect_to edit_user_registration_path(current_user) # edit_user_account_path
    else
      # This was a sign in operation so sign in the user and redirect it to his home page
      if @user.save && authentication.save
        flash[:success] = I18n.t "controllers.omniauth_callbacks.process_callback.success.sign_in", 
                                 :provider => @omniauth[:provider].capitalize,
                                 :account  => @omniauth[:uid] # registration_hash[:email]
        sign_in_and_redirect(:user,@user)
      else
        session[:omniauth] = @omniauth.except('extra')
        flash[:error] = I18n.t "controllers.omniauth_callbacks.process_callback.error.sign_in", 
                               :provider => @omniauth[:provider],
                               :account  => @omniauth[:uid] # registration_hash[:email]
        redirect_to new_user_registration_url # new_registration_users_url
      end
    end
  end

v2.rb

  def process_callback
    logger.debug "Processing #{@omniauth.provider}"
    
    authentication = Authentication.find_by_provider_and_uid(@omniauth['provider'], @omniauth['uid'])
    if authentication # Existing authentication
      flash[:success] = I18n.t "devise.omniauth_callbacks.success", :kind => @omniauth['provider'].titleize
      # flash[:notice] = "Signed in successfully."
      sign_in_and_redirect(:user, authentication.user)
    elsif current_user # User is linking new account
      # při použití kombinace OmniAuth skrz Devise toto neumožní, 
      # ptž :omniauthable nemůže vytvořit uživatele, jeli uživatel přihlášen
      current_user.authentications.create!(:provider => @omniauth['provider'], :uid => @omniauth['uid'],
          :uemail => @omniauth['info']['email'], :uname => @omniauth['info']['name'], :token => @omniauth)
      flash[:notice] = "New Account linked successfully."
      redirect_to authentications_url
    else # Registration of new user 
      user = User.new # create_from_hash(@omniauth)
      user.apply_omniauth(@omniauth)
      if user.save # && user.authentication.save
        flash[:success] = I18n.t "devise.omniauth_callbacks.success", :kind => @omniauth['provider'].titleize
        sign_in_and_redirect(:user, user)
      else
        session[:omniauth] = @omniauth.except('extra')
        flash[:notice] = "Additional info required to proceed the registration."
        flash[:notice] = I18n.t "devise.omniauth_callbacks.fail", :kind => @omniauth['provider'].titleize
        redirect_to new_user_registration_url
      end
    end