Contents

module VestalVersions
  # Allows specific versions to be tagged with a custom string. Useful for assigning a more
  # meaningful value to a version for the purpose of reversion.
  module VersionTagging
    extend ActiveSupport::Concern

    # Adds an instance method which allows version tagging through the parent object.
    # Accepts a single string argument which is attached to the version record associated with
    # the current version number of the parent object.
    #
    # Returns the given tag if successful, nil if not. Tags must be unique within the scope of
    # the parent object. Tag creation will fail if non-unique.
    #
    # Version records corresponding to version number 1 are not typically created, but one will
    # be built to house the given tag if the parent object's current version number is 1.
    def tag_version(tag)
      v = versions.at(version) || versions.build(:number => 1)
      v.tag!(tag)
    end

    # Instance methods included into VestalVersions::Version to enable version tagging.
    module VersionMethods
      extend ActiveSupport::Concern

      included do
        validates_uniqueness_of :tag, :scope => [:versioned_id, :versioned_type], :if => :validate_tags?
      end

      # Attaches the given string to the version tag column. If the uniqueness validation fails,
      # nil is returned. Otherwise, the given string is returned.
      def tag!(tag)
        write_attribute(:tag, tag)
        save ? tag : nil
      end

      # Simply returns a boolean signifying whether the version instance has a tag value attached.
      def tagged?
        !tag.nil?
      end

      def validate_tags?
        tagged? && tag != 'deleted'
      end
    end

    Version.class_eval{ include VersionMethods }
  end
end

Version data entries

3 entries across 3 versions & 1 rubygems

Version	Path
geothird_vestal_versions-1.2.5	lib/vestal_versions/version_tagging.rb
geothird_vestal_versions-1.2.4	lib/vestal_versions/version_tagging.rb
geothird_vestal_versions-1.2.3	lib/vestal_versions/version_tagging.rb