This module is included in your application controller which makes several methods available to all controllers and views. Here‘s a common example you might add to your application layout file.

  <%% if logged_in? %>
    Welcome <%%= current_<%= user_singular_name %>.username %>.
    <%%= link_to "Edit profile", edit_current_<%= user_singular_name %>_path %> or
    <%%= link_to "Log out", logout_path %>
  <%% else %>
    <%%= link_to "Sign up", signup_path %> or
    <%%= link_to "log in", login_path %>.
  <%% end %>

You can also restrict unregistered users from accessing a controller using a before filter. For example.

  before_filter :login_required, :except => [:index, :show]