mappings.rb

class Target
  class_attribute :index_mappings

  class << self
    def mappings(*args, &block)
      self.index_mappings ||= { options: {}, mappings: {} }

      mappings = nil
      options = nil

      if block_given?
        options = args.extract_options!
        mappings = Elasticsearch::Model::Indexing::Mappings.new(document_type, options)
        mappings.instance_eval(&block)
        mappings = mappings.to_hash[document_type.to_sym][:properties]
      elsif args.first.respond_to?(:to_hash)
        mappings = args.first
      end

      if mappings.present?
        index_mappings[:mappings] = index_mappings[:mappings].deep_merge(mappings.to_hash)
        expire_mappings_hash!
      end

      if options.present?
        index_mappings[:options] = index_mappings[:options].deep_merge(options.to_hash)
        expire_mappings_hash!
      end

      mappings_hash
    end
    alias :mapping :mappings

    def mappings_hash
      @mappings_hash ||= begin
        type_mappings = index_mappings[:options].merge({
          properties: index_mappings[:mappings]
        })

        { document_type.to_sym => type_mappings }
      end
    end

    def expire_mappings_hash!
      @mappings_hash = nil
    end
  end
end