Contents

##
# This concern can be used to monitor associations for changes.
#
# Associations monitored using the methods in this concern will show up in the ActiveRecord model's changes,
# changed and previous_changes methods.
module DirtyAssociations
  extend ActiveSupport::Concern

  module ClassMethods

    ##
    # Creates methods that allows an +association+ to be monitored.
    #
    # The +association+ parameter should be a string or symbol representing the name of an association.
    def monitor_association_changes(association)
      ids = "#{association.to_s.singularize}_ids"
      [association, ids].each do |name|
        define_method "#{name}=" do |value|
          attribute_will_change!(ids)
          super(value)
        end
      end

      define_method "#{ids}_changed?" do
        changed.include?(ids)
      end

      define_method "#{ids}_previously_changed?" do
        previous_changes.keys.include?(ids)
      end
    end
  end
end

Version data entries

3 entries across 3 versions & 1 rubygems

Version	Path
dirty_associations-0.2.1	lib/dirty_associations.rb
dirty_associations-0.2.0	lib/dirty_associations.rb
dirty_associations-0.1.0	lib/dirty_associations.rb