[Beginning Rails 6] Listing 8-16. The create Method in app/controllers/sessions_controller.rb

sessions_controller.rb

class SessionsController < ApplicationController
  def create
    if user = User.authenticate(params[:email], params[:password])
      session[:user_id] = user.id
      redirect_to root_path, notice: "Logged in successfully"
    else
      flash.now[:alert] = "Invalid login/password combination"
      render :new
    end
  end
end