[MODEL] Added Rails-compatible version of pagination support with Kaminari

    # Controller:
    def search
      @articles = Article.search(params[:q]).page(params[:page]).records

      render :action => "index"
    end

    # View:
    <%= paginate @articles %>

Added integration tests.

TODO: Make the <Response> object lazy loaded.

Author: karmi

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

@@ -31,14 +31,14 @@ def initialize(klass, search, response)
         #
         def results
           @response ||= search.execute!
-          @results  ||= Results.new(klass, response)
+          @results  ||= Results.new(klass, response, nil, self)
         end
 
         # Return the collection of records from the database
         #
         def records
           @response ||= search.execute!
-          @records  ||= Records.new(klass, response, results)
+          @records  ||= Records.new(klass, response, results, self)
         end
 
       end

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

@@ -4,15 +4,16 @@ module Response
       # Common funtionality for classes in the {Elasticsearch::Model::Response} module
       #
       module Base
-        attr_reader :klass, :response,
+        attr_reader :klass, :response, :response_object,
                     :total, :max_score
 
         # @param klass    [Class] The name of the model class
         # @param response [Hash]  The full response returned from Elasticsearch client
         # @param results  [Results]  The collection of results
         #
-        def initialize(klass, response, results=nil)
+        def initialize(klass, response, results=nil, response_object=nil)
           @klass     = klass
+          @response_object = response_object
           @response  = response
           @total     = response['hits']['total']
           @max_score = response['hits']['max_score']

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

@@ -9,11 +9,20 @@ module Pagination
         #
         module Kaminari
           def self.included(base)
-            # Include the Kaminari modules: Configuration and paging
+            # Include the Kaminari configuration and paging method in response
             #
             base.__send__ :include, ::Kaminari::ConfigurationMethods::ClassMethods
             base.__send__ :include, ::Kaminari::PageScopeMethods
 
+            # Include the Kaminari paging methods in results and records
+            #
+            Elasticsearch::Model::Response::Results.__send__ :include, ::Kaminari::ConfigurationMethods::ClassMethods
+            Elasticsearch::Model::Response::Results.__send__ :include, ::Kaminari::PageScopeMethods
+            Elasticsearch::Model::Response::Records.__send__ :include, ::Kaminari::PageScopeMethods
+
+            Elasticsearch::Model::Response::Results.__send__ :forward, :response_object, :limit_value, :offset_value, :total_count
+            Elasticsearch::Model::Response::Records.__send__ :forward, :response_object, :limit_value, :offset_value, :total_count
+
             base.class_eval <<-RUBY, __FILE__, __LINE__ + 1
               # Define the `page` Kaminari method
               #

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

@@ -17,7 +17,7 @@ class Records
 
         # @see Base#initialize
         #
-        def initialize(klass, response, results)
+        def initialize(klass, response, results=nil, response_object=nil)
           super
           @response = response
           @results  = results

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

@@ -18,7 +18,7 @@ class Results
 
         # @see Base#initialize
         #
-        def initialize(klass, response)
+        def initialize(klass, response, results=nil, response_object=nil)
           super
           # TODO: Configurable custom wrapper
           @results   = response['hits']['hits'].map { |hit| Result.new(hit) }

elasticsearch-model/test/integration/active_record_pagination_test.rb

@@ -0,0 +1,97 @@
+require 'test_helper'
+
+module Elasticsearch
+  module Model
+    class ActiveRecordPaginationTest < Elasticsearch::Test::IntegrationTestCase
+
+      class ::Article < ActiveRecord::Base
+        include Elasticsearch::Model
+
+        settings index: { number_of_shards: 1, number_of_replicas: 0 } do
+          mapping do
+            indexes :title,      type: 'string', analyzer: 'snowball'
+            indexes :created_at, type: 'date'
+          end
+        end
+      end
+
+      Kaminari::Hooks.init
+
+      context "ActiveRecord pagination" do
+        setup do
+          ActiveRecord::Schema.define(:version => 1) do
+            create_table :articles do |t|
+              t.string   :title
+              t.datetime :created_at, :default => 'NOW()'
+            end
+          end
+
+          Article.delete_all
+          Article.__elasticsearch__.create_index! force: true
+
+          68.times do |i| ::Article.create! title: "Test #{i}" end
+
+          Article.import
+          Article.__elasticsearch__.refresh_index!
+        end
+
+        should "be on the first page by default" do
+          records = Article.search('title:test').page(1).records
+
+          assert_equal 25, records.size
+          assert_equal 1, records.current_page
+          assert_equal nil, records.prev_page
+          assert_equal 2, records.next_page
+          assert_equal 3, records.total_pages
+
+          assert   records.first_page?,   "Should be the first page"
+          assert ! records.last_page?,    "Should NOT be the last page"
+          assert ! records.out_of_range?, "Should NOT be out of range"
+        end
+
+        should "load next page" do
+          records = Article.search('title:test').page(2).records
+
+          assert_equal 25, records.size
+          assert_equal 2, records.current_page
+          assert_equal 1, records.prev_page
+          assert_equal 3, records.next_page
+          assert_equal 3, records.total_pages
+
+          assert ! records.first_page?,   "Should NOT be the first page"
+          assert ! records.last_page?,    "Should NOT be the last page"
+          assert ! records.out_of_range?, "Should NOT be out of range"
+        end
+
+        should "load last page" do
+          records = Article.search('title:test').page(3).records
+
+          assert_equal 18, records.size
+          assert_equal 3, records.current_page
+          assert_equal 2, records.prev_page
+          assert_equal nil, records.next_page
+          assert_equal 3, records.total_pages
+
+          assert ! records.first_page?,   "Should NOT be the first page"
+          assert   records.last_page?,    "Should be the last page"
+          assert ! records.out_of_range?, "Should NOT be out of range"
+        end
+
+        should "not load invalid page" do
+          records = Article.search('title:test').page(6).records
+
+          assert_equal 0, records.size
+          assert_equal 6, records.current_page
+          assert_equal 5, records.prev_page
+          assert_equal nil, records.next_page
+          assert_equal 3, records.total_pages
+
+          assert ! records.first_page?,   "Should NOT be the first page"
+          assert   records.last_page?,    "Should be the last page"
+          assert   records.out_of_range?, "Should be out of range"
+        end
+      end
+
+    end
+  end
+end

elasticsearch-model/test/unit/response_pagination_test.rb

@@ -10,11 +10,11 @@ def self.document_type; 'bar'; end
     end
 
     RESPONSE = { 'took' => '5', 'timed_out' => false, '_shards' => {'one' => 'OK'},
-                 'hits' => { 'total' => 100, 'hits' => [ {'_id' => 1} ] } }
+                 'hits' => { 'total' => 100, 'hits' => (1..100).to_a.map { |i| { _id: i } } } }
 
     setup do
-      search    = Elasticsearch::Model::Searching::SearchRequest.new ModelClass, '*'
-      @response = Elasticsearch::Model::Response::Response.new ModelClass, search, RESPONSE
+      @search    = Elasticsearch::Model::Searching::SearchRequest.new ModelClass, '*'
+      @response = Elasticsearch::Model::Response::Response.new ModelClass, @search, RESPONSE
       @response.klass.stubs(:client).returns mock('client')
     end
 
@@ -136,5 +136,31 @@ def self.document_type; 'bar'; end
         assert_equal 100, @response.total_count
       end
     end
+
+    context "results" do
+      setup do
+        @search.stubs(:execute!).returns RESPONSE
+      end
+
+      should "return current page and total count" do
+        assert_equal 1, @response.page(1).results.current_page
+        assert_equal 100, @response.results.total_count
+
+        assert_equal 5, @response.page(5).results.current_page
+      end
+    end
+
+    context "records" do
+      setup do
+        @search.stubs(:execute!).returns RESPONSE
+      end
+
+      should "return current page and total count" do
+        assert_equal 1, @response.page(1).records.current_page
+        assert_equal 100, @response.records.total_count
+
+        assert_equal 5, @response.page(5).records.current_page
+      end
+    end
   end
 end