[MODEL] Added an ActiveRecord specific adapter for Elasticsearch::Model::Response::Records

Example:

  > response.records.class
  => Elasticsearch::Model::Response::Records

  > response.records.records.class
  => ActiveRecord::Relation::ActiveRecord_Relation_Article

  > response.records.to_a
    Article Load (0.2ms)  SELECT "articles".* FROM "articles" WHERE "articles"."id" IN (3, 1)
  => [#<Article id: 3, title: "Foo Foo", published_at: nil, created_at: "2013-11-07 15:09:23", updated_at: "2013-11-07 15:09:23">,
   #<Article id: 1, title: "Foo", published_at: nil, created_at: "2013-11-07 15:09:23", updated_at: "2013-11-07 15:09:23">]

  > response.records.order(id: :desc).to_a
    Article Load (0.3ms)  SELECT "articles".* FROM "articles" WHERE "articles"."id" IN (3, 1) ORDER BY "articles"."id" DESC
  => [#<Article id: 3, title: "Foo Foo", published_at: nil, created_at: "2013-11-07 15:09:23", updated_at: "2013-11-07 15:09:23">,
   #<Article id: 1, title: "Foo", published_at: nil, created_at: "2013-11-07 15:09:23", updated_at: "2013-11-07 15:09:23">]

Author: karmi

elasticsearch-model/lib/elasticsearch/model.rb

@@ -4,12 +4,16 @@
 
 require 'hashie'
 
+require 'elasticsearch/model/adapter'
+require 'elasticsearch/model/adapters/active_record'
+
 require 'elasticsearch/model/response'
 require 'elasticsearch/model/response/base'
 require 'elasticsearch/model/response/result'
 require 'elasticsearch/model/response/results'
 require 'elasticsearch/model/response/records'
 require 'elasticsearch/model/searching'
+
 require 'elasticsearch/model/version'
 
 module Elasticsearch

elasticsearch-model/lib/elasticsearch/model/adapter.rb

@@ -0,0 +1,21 @@
+module Elasticsearch
+  module Model
+    module Adapter
+      def from_class(klass)
+        Adapter.new(klass)
+      end
+      module_function :from_class
+
+      class Adapter
+
+        def initialize(klass)
+        end
+
+        def response
+          Elasticsearch::Model::Adapter::ActiveRecord::Records
+        end
+
+      end
+    end
+  end
+end

elasticsearch-model/lib/elasticsearch/model/adapters/active_record.rb

@@ -0,0 +1,50 @@
+module Elasticsearch
+  module Model
+    module Adapter
+      module ActiveRecord
+
+        module Records
+
+          # Return the `ActiveRecord::Relation` instance
+          #
+          def records
+            sql_records = klass.where(id: @ids)
+
+            # Re-order records based on the order from Elasticsearch hits
+            # by redefining `to_a`, unless the user has called `order()`
+            #
+            sql_records.instance_exec(response['hits']['hits']) do |hits|
+              define_singleton_method :to_a do
+                self.load
+                @records.sort_by { |record| hits.index { |hit| hit['_id'] == record.id.to_s } }
+              end
+            end
+
+            sql_records
+          end
+
+          # Prevent clash with `ActiveSupport::Dependencies::Loadable`
+          #
+          def load
+            records.load
+          end
+
+          # Intercept call to order, so we can ignore the order from Elasticsearch
+          #
+          def order(*args)
+            sql_records = records.__send__ :order, *args
+
+            # Redefine the `to_a` method to the original one
+            #
+            sql_records.instance_exec do
+              define_singleton_method(:to_a) { self.load; @records }
+            end
+
+            sql_records
+          end
+        end
+      end
+
+    end
+  end
+end

elasticsearch-model/lib/elasticsearch/model/response/records.rb

@@ -7,10 +7,13 @@ class Records
         def initialize(klass, response)
           super
           @ids = response['hits']['hits'].map { |hit| hit['_id'] }
-        end
 
-        def records
-          @records = klass.find(@ids)
+          # Include module provided by the adapter in the singleton class ("metaclass")
+          #
+          adapter = Adapter.from_class(klass)
+          metaclass = class << self; self; end
+          metaclass.__send__ :include, adapter.response
+          self
         end
 
         # Delegate methods to `@records`