gistfile1.rb

# /app/models/item.rb
class Item < ActiveRecord::Base
  include ItemSearch
  ...
end

# /app/models/concerns/item_search.rb
module ItemSearch
  extend ActiveSupport::Concern

  module ClassMethods
    def self.search(query_string, opts = {})
      # Build the query
      search_body = Jbuilder.encode do |json|
        json.query do
          json.filtered do
            json.query do
              json.multi_match do
                json.fields %i(description title)
                json.query query_string
              end
            end
            json.filter do
              json.bool do
                json.set! :must, [
                  {
                    :term => {
                      :approved => true
                    }
                  }
                ]
              end
            end
          end
        end
      end
      
      # Execute the query
      results = MyApp::Elasticsearch.client.search \
        :body  => search_body,
        :index => :my_index,
        :type  => :items
        
      # Format the results
      Hashie::Mash.new(results["hits"]).hits
    end
  end
end