Module: Heritage::ActiveRecord::ActsAsHeir

Defined in:
lib/heritage/active_record/acts_as_heir.rb

Defined Under Namespace

Modules: ClassMethods, InstanceMethods

Instance Method Summary collapse

Instance Method Details

#acts_as_heir_of(predecessor_symbol) ⇒ Object 



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# File 'lib/heritage/active_record/acts_as_heir.rb', line 9

def acts_as_heir_of(predecessor_symbol)
  extend ClassMethods
  include InstanceMethods

  class_attribute :_predecessor_klass, :_predecessor_symbol
  self._predecessor_symbol = predecessor_symbol
  self._predecessor_klass = Object.const_get(predecessor_symbol.to_s.camelize)

  has_one :predecessor, :as => :heir, :class_name => predecessor_symbol.to_s.camelize, :autosave => true, :dependent => :destroy

  alias_method_chain :predecessor, :build

  # Expose columns from the predecessor
  self._predecessor_klass.columns.reject{|c| c.primary || c.name =~ /^heir_/}.map(&:name).each do |att|
    define_method(att) do
      predecessor.send(att)
    end
    define_method("#{att}=") do |val|
      predecessor.send("#{att}=",val)
    end
  end

  # Expose associations from the predecessor
  self._predecessor_klass.reflect_on_all_associations.reject{|a| a.name == :heir}.each do |association|
    define_method(association.name) do
      predecessor.send(association.name)
    end
    define_method("#{association.name}=") do |val|
      predecessor.send("#{association.name}=",val)
    end
  end

  # We need to make sure that updated_at values in the predecessor table is updated when the heir is saved.
  before_update :touch_predecessor, :unless => lambda { predecessor.changed? }

  # Expose methods from predecessor
  self._predecessor_klass.get_heritage_exposed_methods.each do |method_symbol|
    define_method(method_symbol.to_s) do |*args|
      if args.length > 0
        predecessor.send(method_symbol.to_s, args)
      else
        predecessor.send(method_symbol.to_s)
      end
    end
  end
end

#child_of(parent_symbol) ⇒ Object 



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# File 'lib/heritage/active_record/acts_as_heir.rb', line 5

def child_of(parent_symbol)
  acts_as_heir_of(parent_symbol)
end