Action Aliases

You will usually be working with four actions when defining and checking permissions: :read, :create, :update, :destroy. These aren't the same as the 7 RESTful actions in Rails. CanCan automatically adds some default aliases for mapping those actions.

alias_action :index, :show, :to => :read
alias_action :new, :to => :create
alias_action :edit, :to => :update

Notice the edit action is aliased to update. This means if the user is able to update a record he also has permission to edit it. You can define your own aliases in the Ability class.

alias_action :update, :destroy, :to => :modify
can :modify, Comment
can? :update, Comment # => true

The alias_action method is an instance method and usually called in initialize. See Custom Actions for information on adding other actions.