Module CanCan::ControllerAdditions
In: lib/cancan/controller_additions.rb

This module is automatically included into all controllers. It also makes the "can?" and "cannot?" methods available to all views.

Methods

Classes and Modules

Module CanCan::ControllerAdditions::ClassMethods

Public Class methods

Public Instance methods

Raises a CanCan::AccessDenied exception if the current_ability cannot perform the given action. This is usually called in a controller action or before filter to perform the authorization.

  def show
    @article = Article.find(params[:id])
    authorize! :read, @article
  end

A :message option can be passed to specify a different message.

  authorize! :read, @article, :message => "Not authorized to read #{@article.name}"

You can rescue from the exception in the controller to customize how unauthorized access is displayed to the user.

  class ApplicationController < ActionController::Base
    rescue_from CanCan::AccessDenied do |exception|
      flash[:error] = exception.message
      redirect_to root_url
    end
  end

See the CanCan::AccessDenied exception for more details on working with the exception.

See the load_and_authorize_resource method to automatically add the authorize! behavior to the default RESTful actions.

Use in the controller or view to check the user‘s permission for a given action and object.

  can? :destroy, @project

You can also pass the class instead of an instance (if you don‘t have one handy).

  <% if can? :create, Project %>
    <%= link_to "New Project", new_project_path %>
  <% end %>

This simply calls "can?" on the current_ability. See Ability#can?.

Convenience method which works the same as "can?" but returns the opposite value.

  cannot? :destroy, @project

Creates and returns the current user‘s ability and caches it. If you want to override how the Ability is defined then this is the place. Just define the method in the controller to change behavior.

  def current_ability
    # instead of Ability.new(current_user)
    @current_ability ||= UserAbility.new(current_account)
  end

Notice it is important to cache the ability object so it is not recreated every time.

[Validate]