Module: CanCan::ControllerAdditions::ClassMethods

Defined in:
lib/cancan/controller_additions.rb

Instance Method Summary collapse

Instance Method Details

#authorize_resource(*args) ⇒ Object

Sets up a before filter which authorizes the resource using the instance variable. For example, if you have an ArticlesController it will check the @article instance variable and ensure the user can perform the current action on it. Under the hood it is doing something like the following.

authorize!(params[:action].to_sym, @article || Article)

Call this method directly on the controller class.

class BooksController < ApplicationController
  authorize_resource
end

If you pass in the name of a resource which does not match the controller it will assume it is a parent resource.

class BooksController < ApplicationController
  authorize_resource :author
  authorize_resource :book
end

Here it will authorize :show, @author on every action before authorizing the book.

That first argument is optional and will default to the singular name of the controller. A hash of options (see below) can also be passed to this method to further customize it.

See load_and_authorize_resource to automatically load the resource too.

Options:

:only

Only applies before filter to given actions.

:except

Does not apply before filter to given actions.

:parent

True or false depending on if the resource is considered a parent resource. This defaults to true if a resource name is given which does not match the controller.

:class

The class to use for the model (string or constant). This passed in when the instance variable is not set. Pass false if there is no associated class for this resource and it will use a symbol of the resource name.

:instance_name

The name of the instance variable for this resource.

:through

Authorize conditions on this parent resource when instance isn’t available.



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# File 'lib/cancan/controller_additions.rb', line 161

def authorize_resource(*args)
  cancan_resource_class.add_before_filter(self, :authorize_resource, *args)
end

#cancan_resource_class ⇒ Object 



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# File 'lib/cancan/controller_additions.rb', line 197

def cancan_resource_class
  if ancestors.map(&:to_s).include? "InheritedResources::Actions"
    InheritedResource
  else
    ControllerResource
  end
end

#check_authorization(*args) ⇒ Object

Add this to a controller to ensure it performs authorization through authorized! or authorize_resource call. If neither of these authorization methods are called, a CanCan::AuthorizationNotPerformed exception will be raised. This is normally added to the ApplicationController to ensure all controller actions do authorization.

class ApplicationController < ActionController::Base
  check_authorization
end

Any arguments are passed to the after_filter it triggers.

See skip_authorization to bypass this check on specific controller actions.



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# File 'lib/cancan/controller_additions.rb', line 176

def check_authorization(*args)
  self.after_filter(*args) do |controller|
    unless controller.instance_variable_defined?(:@_authorized)
      raise AuthorizationNotPerformed, "This action failed the check_authorization because it does not authorize_resource. Add skip_authorization to bypass this check."
    end
  end
end

#load_and_authorize_resource(*args) ⇒ Object

Sets up a before filter which loads and authorizes the current resource. This performs both load_resource and authorize_resource and accepts the same arguments. See those methods for details.

class BooksController < ApplicationController
  load_and_authorize_resource
end



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# File 'lib/cancan/controller_additions.rb', line 14

def load_and_authorize_resource(*args)
  cancan_resource_class.add_before_filter(self, :load_and_authorize_resource, *args)
end

#load_resource(*args) ⇒ Object

Sets up a before filter which loads the model resource into an instance variable. For example, given an ArticlesController it will load the current article into the @article instance variable. It does this by either calling Article.find(params) or Article.new(params) depending upon the action. The index action will automatically set @articles to Article.accessible_by(current_ability).

If a conditions hash is used in the Ability, the new and create actions will set the initial attributes based on these conditions. This way these actions will satisfy the ability restrictions.

Call this method directly on the controller class.

class BooksController < ApplicationController
  load_resource
end

A resource is not loaded if the instance variable is already set. This makes it easy to override the behavior through a before_filter on certain actions.

class BooksController < ApplicationController
  before_filter :find_book_by_permalink, :only => :show
  load_resource

  private

  def find_book_by_permalink
    @book = Book.find_by_permalink!(params[:id)
  end
end

If a name is provided which does not match the controller it assumes it is a parent resource. Child resources can then be loaded through it.

class BooksController < ApplicationController
  load_resource :author
  load_resource :book, :through => :author
end

Here the author resource will be loaded before each action using params. The book resource will then be loaded through the @author instance variable.

That first argument is optional and will default to the singular name of the controller. A hash of options (see below) can also be passed to this method to further customize it.

See load_and_authorize_resource to automatically authorize the resource too.

Options:

:only

Only applies before filter to given actions.

:except

Does not apply before filter to given actions.

:through

Load this resource through another one. This should match the name of the parent instance variable or method.

:shallow

Pass true to allow this resource to be loaded directly when parent is nil. Defaults to false.

:singleton

Pass true if this is a singleton resource through a has_one association.

:parent

True or false depending on if the resource is considered a parent resource. This defaults to true if a resource name is given which does not match the controller.

:class

The class to use for the model (string or constant).

:instance_name

The name of the instance variable to load the resource into.

:find_by

Find using a different attribute other than id. For example.

load_resource :find_by => :permalink # will use find_by_permlink!(params[:id])
:collection

Specify which actions are resource collection actions in addition to :index. This is usually not necessary because it will try to guess depending on if the id param is present.

load_resource :collection => [:sort, :list]
:new

Specify which actions are new resource actions in addition to :new and :create. Pass an action name into here if you would like to build a new resource instead of fetch one.

load_resource :new => :build



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# File 'lib/cancan/controller_additions.rb', line 108

def load_resource(*args)
  cancan_resource_class.add_before_filter(self, :load_resource, *args)
end

#skip_authorization(*args) ⇒ Object

Call this in the class of a controller to skip the check_authorization behavior on the actions.

class HomeController < ApplicationController
  skip_authorization :only => :index
end

Any arguments are passed to the before_filter it triggers.



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# File 'lib/cancan/controller_additions.rb', line 191

def skip_authorization(*args)
  self.before_filter(*args) do |controller|
    controller.instance_variable_set(:@_authorized, true)
  end
end