cancan/lib/cancan/controller_resource.rb
2010-05-21 13:41:24 -07:00

55 lines
1.9 KiB
Ruby

module CanCan
# Used internally to load and authorize a given controller resource.
# This manages finding or building an instance of the resource. If a
# parent is given it will go through the association.
class ControllerResource # :nodoc:
def initialize(controller, name, parent = nil, options = {})
raise ImplementationRemoved, "The :class option has been renamed to :resource for specifying the class in CanCan." if options.has_key? :class
@controller = controller
@name = name
@parent = parent
@options = options
end
# Returns the class used for this resource. This can be overriden by the :resource option.
# Sometimes one will use a symbol as the resource if a class does not exist for it. In that
# case "find" and "build" should not be called on it.
def model_class
resource_class = @options[:resource]
if resource_class.nil?
@name.to_s.camelize.constantize
elsif resource_class.kind_of? String
resource_class.constantize
else
resource_class # could be a symbol
end
end
def find(id)
self.model_instance ||= base.find(id)
end
# Build a new instance of this resource. If it is a class we just call "new" otherwise
# it's an associaiton and "build" is used.
def build(attributes)
self.model_instance ||= (base.kind_of?(Class) ? base.new(attributes) : base.build(attributes))
end
def model_instance
@controller.instance_variable_get("@#{@name}")
end
def model_instance=(instance)
@controller.instance_variable_set("@#{@name}", instance)
end
private
# The object that methods (such as "find", "new" or "build") are called on.
# If there is a parent it will be the association, otherwise it will be the model's class.
def base
@parent ? @parent.model_instance.send(@name.to_s.pluralize) : model_class
end
end
end