lighttroupe/luz-next

# Mixin: Callbacks.

module Callbacks
    def self.included(base) #:nodoc:
        base.extend(ClassMethods)
    end

    ###################################################################
    # Class-level methods
    ###################################################################

    module ClassMethods
        def callback(*names)
            names.to_a.each { |name|
                self.class_eval <<-end_class_eval
                    def on_#{name}(&proc)
                        @#{name}_handlers ||= []
                        @#{name}_handlers << proc
                    end

                    def on_#{name}_with_init(&proc)
                        @#{name}_handlers ||= []
                        @#{name}_handlers << proc
                        proc.call
                    end

                    def #{name}_notify(*args)
                        @#{name}_handlers.each { |handler| handler.call(*args) } if @#{name}_handlers
                    end
                end_class_eval
            }
        end

        def unique_callback(*names)
            names.to_a.each { |name|
                self.class_eval <<-end_class_eval
                    def on_#{name}(&proc)
                        @#{name}_handler = proc
                    end

                    def #{name}_notify(*args)
                        @#{name}_handler.call(*args) if @#{name}_handler
                    end
                end_class_eval
            }
        end
    end
end