lib/has_draft.rb
module HasDraft
def self.included(base)
base.extend ClassMethods
end
module ClassMethods
def has_draft(options = {}, &block)
return if self.included_modules.include?(HasDraft::InstanceMethods)
include HasDraft::InstanceMethods
cattr_accessor :draft_class_name, :draft_foreign_key, :draft_table_name, :draft_columns
self.draft_class_name = options[:class_name] || 'Draft'
self.draft_foreign_key = options[:foreign_key] || self.to_s.foreign_key
self.draft_table_name = options[:table_name] || "#{table_name_prefix}#{base_class.name.demodulize.underscore}_drafts#{table_name_suffix}"
# Default parent association
options[:belongs_to] = self.to_s.demodulize.underscore.to_sym if options[:belongs_to].nil?
# Create Relationship to Draft Copy
class_eval do
has_one :draft, :class_name => "#{self.to_s}::#{draft_class_name}",
:foreign_key => draft_foreign_key,
:dependent => :destroy,
:inverse_of => options[:belongs_to]
scope :with_draft, lambda { includes(:draft).where("#{draft_table_name}.id IS NOT NULL") }
scope :without_draft, lambda { includes(:draft).where("#{draft_table_name}.id IS NULL") }
end
# Default parent class to ActiveRecord::Base
options[:extends] = ActiveRecord::Base if options[:extends].nil?
# Dynamically Create Model::Draft Class
const_set(draft_class_name, Class.new(options[:extends]))
draft_class.cattr_accessor :original_class
draft_class.original_class = self
draft_class.table_name = draft_table_name
# Draft Parent Association
draft_class.belongs_to options[:belongs_to], :class_name => "::#{self.to_s}", :foreign_key => draft_foreign_key, :inverse_of => :draft
# Block extension
draft_class.class_eval(&block) if block_given?
# Finally setup which columns to draft
self.draft_columns = draft_class.new.attributes.keys - [draft_class.primary_key, draft_foreign_key, 'created_at', 'updated_at', inheritance_column]
end
def draft_class
const_get(draft_class_name)
end
end
module InstanceMethods
def has_draft?
!self.draft.nil?
end
def save_to_draft(perform_validation = true)
return false if perform_validation and !self.valid?
instantiate_draft! unless has_draft?
copy_attributes_to_draft
self.draft.save(perform_validation)
self.reload
end
def instantiate_draft
self.build_draft
copy_attributes_to_draft
before_instantiate_draft
self.draft.tap(&:save)
end
def instantiate_draft!
instantiate_draft do |draft|
draft.save unless self.new_record?
end
end
def copy_attributes_to_draft
self.class.draft_columns.each do |attribute|
self.draft.send("#{attribute}=", send(attribute))
end
self
end
def copy_attributes_from_draft
self.class.draft_columns.each do |attribute|
self.send("#{attribute}=", self.draft.send(attribute))
end
self
end
def before_instantiate_draft
end
def replace_with_draft!
copy_attributes_from_draft
before_replace_with_draft
self.save unless self.new_record?
self
end
def before_replace_with_draft
end
def destroy_draft!
before_destroy_draft
self.draft.destroy if self.draft
self.draft(true)
end
def before_destroy_draft
end
end
end
require "has_draft/railtie"