Setting Up Devise in 10 steps - Anonymous Function

Lets create a small app that utilizes Devise and provides links to sign up, log in and logout.

Step 1.

rails new MyApp (will create a rails app)

Step 2.

gem ‘devise’ (specify devise gem inside Gemfile) run bundle install (in the terminal)

Step 3.

rails generate devise:install

Step 4.

rails generate devise User

Step 5.

run rake db:migrate (It will create a users table with attributes username and email, to add any other simply add them in users table in migration before this step)

Step 6.

Now we have a devise user model which can Sign In/Sign Up/Sig Out. Devise has hidden cotrollers and views which can be pulled using

rails generate devise:views users

which will show us users/confirmations, users/mailer, users/registrations etc inside the views directory.

Step 7.

Similarly devise controllers can be made visible by

rails g devise:controllers users

which will generate controllers/users/confirmation_controller.rb and controllers/users/registrations_controller.rb etc

Step 8.

Either create a controller manually or use

rails g controller Welcome

lets create one manually in app/controllers create a file welcome_controller.rb and code as follows

class WelcomeController< ApplicationController
  def index
      @user_email =  current_user ? current_user.email.capitalize : "Please Log In!"
  end
end 

now our index action will be able to return current user’s email or a string showing “Please Log In!” when there is no one logged in.

lets create app/views/welcome/index.html.erb with the following code

<h1>Welcome Friend <%=@user_email%></h1>

Step 9.

lets direct our user to the welcome index action by providing a route in config/routes.rb

`get '/', to: welcome#index`

Step 10.

At this point we can see a message but see no links to all registration actions… However we can access them using routes which can be seen by running rake routes command. Lets make those routes visible to everyone by adding the following lines of code in views/welcome/index.html.erb

<h1>Welcome Friend  <%=@user%></h1>
<% if user_signed_in? %>
	Logged in as <strong><%= current_user.email %></strong>.
	<%= link_to 'Edit profile', edit_user_registration_path%> |
	<%= link_to "Logout", destroy_user_session_path, method: :delete  %>
<% else %>
	<%= link_to "Sign up", new_user_registration_path  %> |
	<%= link_to "Login", new_user_session_path  %>
<% end %> where  user_signed_in? is a devise built in method which returns a boolean value true or false.  Similarly current_user is also a built in method provided by devise which gives us current user.  