To Examples

LoginRegistration Example

Directions

1. Create a Rails project named LoginRegistration.
2. Create a Rails model named Login:
   

   > rails g model Login user:string password:string
   

3. Create Rails controllers Logins and Info:
   

   > rails g controller Logins new_login show_logins ⇓
       login_form registration_confirmation
   > rails g controller info page1
   

   page1 represents your website content that should be password protected.
4. Use the following source code for the indicated files:
   

   ---- LoginController/app/controllers/logins_controller.rb --------------------------
   
   require 'digest/md5'
   
   class LoginsController < ApplicationController
     def new_login
     end
   
     def show_logins
     end
     
     def registration_confirmation
     	@login = Login.new
       @login.user = params[:user]
       pw_from_user = params[:pw]
       confirm_from_user = params[:confirm_pw]
       if pw_from_user != confirm_from_user
         redirect_to logins_new_login_path, 
           notice: 'Password does not match confirmation.'
         return
       end
       @login.password = Digest::MD5.hexdigest(pw_from_user)    
       if @login.save
         @msg = 'New user was successfully registered.'
         @all_logins = Login.all
       else
         if @login.errors.any?
           cnt = @login.errors.count
           error_messages = cnt.to_s + " " + "error".pluralize(cnt) + 
             " prohibited password from being created.\n"
           @login.errors.full_messages.each do |msg|
             error_messages += "--" + msg + ".\n"
           end
         end
   	  redirect_to logins_new_login_path, notice: error_messages
         return
       end 
     end
   
     def login_form  
   	 
       # User must login again when arriving at the login page,
       # even if already logged in previously.
   	reset_session
   	
       # Get username and password
       user_from_login = params[:user_from_login]
       pw_from_login = params[:pw_from_login]
   	
       # Get password from database for entered username.  
       # If password from database matches the entered password,
       # store true in session variable so user need not login again.
       if !user_from_login.blank?
         pw_array = Login.where(user: user_from_login)
         encoded_pw = Digest::MD5.hexdigest(pw_from_login)	
         if pw_array.length > 0
           pw_from_db = pw_array[0].password
           if pw_from_db == encoded_pw
             session[:logged_in] = true
             redirect_to info_page1_path
           end
         end
       end
     end
   	
     def logout
   	
       # If user logs out from any page,
       # reset session variable to false.
       reset_session
   	
       # Go back to login again.
       redirect_to logins_login_form_path
   	
     end 
   end
   
   ---- LoginController/app/views/logins/new_login.html.erb ---------------------------
   
   <h1>Login Registration</h1>
   
   <pre style="font-family: arial;">
     <%= flash[:notice] %>
   </pre>
   
   <p><%= form_tag logins_registration_confirmation_path do %>
     <table>
       <tr> 
         <td class="r">Username</td> 
         <td><%= text_field_tag :user, '' %></td>
       </tr>
       <tr> 
         <td class="r">Password</td> 
         <td><%= password_field_tag :pw, '' %></td>
       </tr>
       <tr> 
         <td class="r">Confirmation</td> 
         <td><%= password_field_tag :confirm_pw, '' %></td>
       </tr>
       <tr>
         <td>&nbsp;</td>
         <td><%= submit_tag 'Register' %>
       </tr>
     </table>
   <% end %></p>
   
   ---- LoginController/app/views/logins/registration_confirmation --------------------
   
   <h2>Registration Confirmation</h2>
   
   <p>New user registration confirmed.</p>
   
   <p><%= link_to 'To Login Form', logins_login_form_path %></p>
   <p><%= link_to 'Show All Logins', logins_show_logins_path %></p>
   
   ---- LoginController/app/views/logins/login_form.html.erb --------------------------
   
   <h1>Login Form</h1>
   
   <%= form_tag logins_login_form_path do %>
     <table>
       <tr> 
         <td style="text-align:right">Username:</td> 
         <td><%= text_field_tag :user_from_login, '' %></td>
       </tr>
       <tr>
         <td style="text-align:right">Password:</td> 
         <td><%= password_field_tag :pw_from_login, '' %></td>
       </tr>
       <tr>
         <td>&nbsp;</td>
         <td><%= submit_tag 'Login' %></td> 
       </tr>
     <table>
   <% end %>
   
   <p><%= link_to 'Register New User', logins_new_login_path %></p>
   

   ---- LoginController/app/views/logins/show_logins.html.erb -------------------------
   
   <h1>Current Registered Users</h1>
   
   <table>
     <tr>
       <td>User</td>
       <td>Encrypted Password</td>
     </tr>
   
     <% Login.all.each do |login| %> 
       <tr>
         <td><%= login.user %></td>
         <td><%= login.password %></td>
       </tr>
     <% end %>
   </table>
   
   <p><%= link_to 'To Login Form', logins_login_form_path %></p>
   
   ---- LoginController/app/controllers/info_controller.rb ----------------------------
   
   class InfoController < ApplicationController
     def page1
     end
   
   private
     def check_logged_in
       if !session[:logged_in]
         redirect_to logins_logins_form_path
       end
     end
   end
   
   ---- LoginController/app/views/info/page1.html.erb ---------------------------------
   
   <%= form_tag logins_logout_path, class: 'r' do %>
     <%= submit_tag 'Logout' %>
   <% end %>
   
   <h1>Info Page</h1>
   
   <p>This is the password protected page.</p>
   
   ---- LoginController/assets/stylesheets/application.css ----------------------------
   
   .r { text-align: right }
   
   ---- LoginController/config/routes.rb ----------------------------------------------
   
   Rails.application.routes.draw do
     get  'logins/new_login'
     get 'logins/registration_confirmation'
     post 'logins/registration_confirmation'
     get 'logins/login_form'
     post 'logins/login_form'
     get  'logins/show_logins'
     post 'logins/show_logins'
     get 'logins/logout'
     post 'logins/logout'
     get 'info/page1'
   end