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.

: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). 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.

:id_param

Find using a param key other than :id. For example:

load_resource :id_param => :url # will use find(params[:url])
:through

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

:prepend

Passing true will use prepend_before_action instead of a normal before_action.



185
186
187
 
# File 'lib/cancan/controller_additions.rb', line 185

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

#cancan_resource_class ⇒ Object 



291
292
293
 
# File 'lib/cancan/controller_additions.rb', line 291

def cancan_resource_class
  ControllerResource
end

#cancan_skipper ⇒ Object 



295
296
297
 
# File 'lib/cancan/controller_additions.rb', line 295

def cancan_skipper
  self._cancan_skipper ||= { authorize: {}, load: {} }
end

#check_authorization(options = {}) ⇒ Object

Add this to a controller to ensure it performs authorization through authorize! 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

See skip_authorization_check to bypass this check on specific controller actions.

Options:

:only

Only applies to given actions.

:except

Does not apply to given actions.

:if

Supply the name of a controller method to be called. The authorization check only takes place if this returns true.

check_authorization :if => :admin_controller?
:unless

Supply the name of a controller method to be called. The authorization check only takes place if this returns false.

check_authorization :unless => :devise_controller?



265
266
267
268
269
270
271
272
273
274
275
276
277
 
# File 'lib/cancan/controller_additions.rb', line 265

def check_authorization(options = {})
  block = proc do |controller|
    next if controller.instance_variable_defined?(:@_authorized)
    next if options[:if] && !controller.send(options[:if])
    next if options[:unless] && controller.send(options[:unless])

    raise AuthorizationNotPerformed,
          'This action failed the check_authorization because it does not authorize_resource. ' \
          'Add skip_authorization_check to bypass this check.'
  end

  send(:after_action, options.slice(:only, :except), &block)
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



15
16
17
 
# File 'lib/cancan/controller_additions.rb', line 15

def load_and_authorize_resource(*args)
  cancan_resource_class.add_before_action(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_action on certain actions.

class BooksController < ApplicationController
  before_action :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.

:through_association

The name of the association to fetch the child records through the parent resource. This is normally not needed because it defaults to the pluralized resource name.

: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_permalink!(params[:id])
:id_param

Find using a param key other than :id. For example:

load_resource :id_param => :url # will use find(params[:url])
: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
:prepend

Passing true will use prepend_before_action instead of a normal before_action.



121
122
123
 
# File 'lib/cancan/controller_additions.rb', line 121

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

#skip_authorization_check(*args) ⇒ Object

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

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

Any arguments are passed to the before_action it triggers.



286
287
288
289
 
# File 'lib/cancan/controller_additions.rb', line 286

def skip_authorization_check(*args)
  block = proc { |controller| controller.instance_variable_set(:@_authorized, true) }
  send(:before_action, *args, &block)
end

#skip_authorize_resource(*args) ⇒ Object

Skip the authorization behavior of CanCan. This is useful when using load_and_authorize_resource but want to only do loading on certain actions. You can pass :only and :except options to specify which actions to skip the effects on. It will apply to all actions by default.

class ProjectsController < ApplicationController
  load_and_authorize_resource
  skip_authorize_resource :only => :index
end

You can also pass the resource name as the first argument to skip that resource.



229
230
231
232
233
 
# File 'lib/cancan/controller_additions.rb', line 229

def skip_authorize_resource(*args)
  options = args.extract_options!
  name = args.first
  cancan_skipper[:authorize][name] = options
end

#skip_load_and_authorize_resource(*args) ⇒ Object

Skip both the loading and authorization behavior of CanCan for this given controller. This is primarily useful to skip the behavior of a superclass. You can pass :only and :except options to specify which actions to skip the effects on. It will apply to all actions by default.

class ProjectsController < SomeOtherController
  skip_load_and_authorize_resource :only => :index
end

You can also pass the resource name as the first argument to skip that resource.



198
199
200
201
 
# File 'lib/cancan/controller_additions.rb', line 198

def skip_load_and_authorize_resource(*args)
  skip_load_resource(*args)
  skip_authorize_resource(*args)
end

#skip_load_resource(*args) ⇒ Object

Skip the loading behavior of CanCan. This is useful when using load_and_authorize_resource but want to only do authorization on certain actions. You can pass :only and :except options to specify which actions to skip the effects on. It will apply to all actions by default.

class ProjectsController < ApplicationController
  load_and_authorize_resource
  skip_load_resource :only => :index
end

You can also pass the resource name as the first argument to skip that resource.



213
214
215
216
217
 
# File 'lib/cancan/controller_additions.rb', line 213

def skip_load_resource(*args)
  options = args.extract_options!
  name = args.first
  cancan_skipper[:load][name] = options
end