How to allow only the admin to view link

I making my Admin User using Michael Hartl's Rails 3 Tutorial.I am making it so my admin user can only see the Index.html.erb for all users. So, How do I allow my link to be viewed by my admin user only?

This is whats in my UsersController:

before_filter :authenticate, :only => [:destroy,:index,:show,:edit, :update]
before_filter :correct_user, :only开发者_Go百科 => [:edit, :update]
before_filter :admin_user,   :only => [:index,:destroy]
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private
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def admin_user
    authenticate
    redirect_to(root_path) unless current_user.admin?
end 

This is what i'm trying to edit for Admin to see only:

 <% if signed_in? %>        
      <%= link_to "Users", users_path %>
 <% end %>

Write a helper method for that so that your views are clean and readable.

your_view.html.erb

<% link_to "Users", users_path if admin? %>

helpers/application_helper.rb

def admin?
  @current_user.name == "Mr.Wallinzi"
  # I made up the line above. Implement your own checks according to your setup
end

I use account_type as an attribute for a user. So I wrote something like

def is_admin
   return true if self.account_type == 1 #The admin account type
end

So...

<%if signed_in? && @active_user.is_admin %>      
  <%= link_to "Users", users_path %></div>
<% end %>

If you use Devise, you could easily achieve that in few lines:

1- Add admin attribute to Devise table:

a. You can add it using migration: $ rails generate migration add_admin_to_users admin:boolean. Your migration will now look like this:

  class AddAdminToUsers < ActiveRecord::Migration
    def change
      add_column :users, :admin, :boolean, :default => false
    end
  end

b. Also you can add it to Device table before migration t.boolean :admin, null: false, default: false

2- In your view you can this so:

<%= link_to "Users", users_path if current_user.admin? %>

After you add admin? to Devise table it becomes an attribute similar to email and others. And it ends with question mark ? because it's a boolean type.