gem 'cancan'

class Ability

  include CanCan::Ability

  def initialize(user)

  end

end

class Ability

  include CanCan::Ability

 

  def initialize(user)

    user ||= User.new

    if user.role == "admin"

      can :manage, Post

    elsif user.role == "moderator"

      can :update, Post

      can :read, Post

    else

      can :read, Post

    end

  end    

end

<% if can? :update, @post %>

  <%= link_to 'Edit', edit_post_path(@post) %> |

<% end %>

<% if can? :destroy, @post %>

  <%= link_to 'Destroy', post_path(@post), :method => :delete %> |

<% end %>

load_and_authorize_resource

rescue_from CanCan::AccessDenied do |exception|

  flash[:notice] = "Access denied!"

  redirect_to root_url

end