hash_for_includes_all_masters.rb

def hash_for_includes_all_masters(recursive=true, all_associations=[])
  all_associations << self.to_s
  result_arr = []

  self.reflect_on_all_associations.each do |model|
    association_name = model.name
    class_name = model.class_name
    next if all_associations.include?(class_name)
    next unless class_name.include?('Master')
    next if model.options.has_key?(:polymorphic)

    # when depth:1
    (result_arr << association_name.to_sym) and next unless recursive

    # when recursive
    tmp = class_name.classify.constantize.hash_for_includes_all_masters(true, all_associations)

    if tmp.blank?
      # has no relation
      result_arr << association_name.to_sym
    else
      # has relation(s)
      result_arr << Hash[association_name, tmp]
    end
  end
  result_arr
end