Rails::Initailizer.run do |config|
  …
  config.gem "declarative_authorization", :source => "http://gemcutter.org"
  …

$ rake gems:install

Vytvoříme si soubor config/authorization_rules.rb

authorization do
    role :admin do
        has_persmission_on [:articles, :comments], :to => [:index, :show, :new, :create, :edit, :update, :destroy]
    end
end

V příslušném datovém modelu pak

# File: app/models/user.rb
class User < ActiveRecord::Base
    acts_as_authentic  # Použit gem authentic
    …
    has_many :roles, :through => :assignemnts

    def role_symbols
        # [:admin] if admin?
        roles.map do |role|
	    role.name.underscore.to_sym
        end
    end
end

class ApplicationController < ActionController::Base
    include Authentication
    helper :all
    protect_from_frogery
    before_filter {|c| Authorization.current_user = c.current_user}
end

class ArticlesController < ApplicationController
    filter_resource_access
end

# File: config/authorization_rules.rb
authorization do
    role :admin do
        has_persmission_on [:articles, :comments], :to => [:index, :show, :new, :create, :edit, :update, :destroy]
    end

    role :quest do
        has_persmission_on :articles, :to => [:index, :show]
	has_persmission_on :comments, :to => [:new, :create]
    end
end

Změny v pohledu

# File: .../show.html.erb
…
    <% if permitted_to? :edit, @article %>
      <%= link_to "Edit", edit_article_path(@article) %>
    <% end %>
…

# File: config/authorization_rules.rb
…
    role :quest do
        has_persmission_on :articles, :to => [:index, :show]
	has_persmission_on :comments, :to => [:new, :create]
    has_persmission_on :comments, :to => [:edit, :update] do
            if_attribute :user => is { user }
        end
    end
…

# File: .../application_controller.rb
class ApplicationController < ActionController::Base
    include Authentication
    helper :all
    protect_from_frogery
    before_filter {|c| Authorization.current_user = c.current_user}

    protected
    def permission_denied
        flash[:error] = "Litujeme, ale nemáte oprávnění přístupu k té stránce."
        redirect_ro root_url
    end
end