This is code so that the nav bar will show the correct corresponding user page where the devise gem is used to create 3 separate user classes: User, Admin, Company User. I think there are instances where developers who choose not to go down the STI route. There are 2 parts to the code. First a header partial where the conditions are set for the …

_header.html.erb

<ul class="left">
  <% if user_signed_in? %>
    <li><%= link_to "Home Page", root_path %></li>
  <% elsif admin_signed_in? %>
    <li><%= link_to "Home Page", root_path %></li>
		<li><%= link_to "Admin Home Page", admin_path %></li>
	<% elsif company_user_signed_in? %>
		<li><%= link_to "Home Page", root_path %></li>
		<li><%= link_to "Company Home Page", company_path %></li>
	<% else %>
		<li><%= link_to "Home Page", root_path %></li>
		<li><%= link_to "Admin Home Page", admin_path %></li>
		<li><%= link_to "Company Home Page", company_path %></li>
	<% end %>	
</ul>
<ul class="right">			
	<% if user_signed_in? %>
		<li><%= link_to "Edit Profile", edit_user_registration_path %></li>
		<li><%= link_to "Logout", destroy_user_session_path, method: :delete %></li>
	<% elsif admin_signed_in? %>
		<li><%= link_to "Edit Profile", edit_admin_registration_path %></li>
		<li><%= link_to "Logout", destroy_admin_session_path, method: :delete %></li>	
	<% elsif company_user_signed_in? %>
		<li><%= link_to "Edit Profile", edit_company_user_registration_path %></li>
		<li><%= link_to "Logout", destroy_company_user_session_path, method: :delete %></li>
	<% elsif params[:action] == 'company_user' %>
		<li><%= link_to "Company Login", new_company_user_session_path %></li>			
	<% elsif params[:action] == 'admin' %>	
		<li><%= link_to "Admin Login", new_admin_session_path %></li>
	<% else %>
		<li><%= link_to "User Login", new_user_session_path %></li>
	<% end %>
</ul>

application_controller.rb

# Stick this in your applciation controller file somewhere so that after you sign in, you will be taken to the correct user page
def after_sign_in_path_for(resource)
   case resource
   when User then '/'
   when Admin then '/admin'
   when CompanyUser then '/company'
   end    
end