[MODEL] Added first version of pagination support with Kaminari

See: https://github.com/amatsuda/kaminari

Author: karmi

Diff for: elasticsearch-model/elasticsearch-model.gemspec

@@ -35,6 +35,7 @@ Gem::Specification.new do |s|
   s.add_development_dependency "activerecord",  "> 4.0"
 
   s.add_development_dependency "oj"
+  s.add_development_dependency "kaminari"
 
   s.add_development_dependency "shoulda-context"
   s.add_development_dependency "mocha"

Diff for: elasticsearch-model/examples/activerecord_article.rb

@@ -11,6 +11,7 @@
 require 'logger'
 require 'ansi/core'
 require 'active_record'
+require 'kaminari'
 
 require 'elasticsearch/model'
 
@@ -25,6 +26,8 @@
   end
 end
 
+Kaminari::Hooks.init
+
 class Article < ActiveRecord::Base
 end
 

Diff for: elasticsearch-model/lib/elasticsearch/model.rb

@@ -27,9 +27,14 @@
 require 'elasticsearch/model/response/result'
 require 'elasticsearch/model/response/results'
 require 'elasticsearch/model/response/records'
+require 'elasticsearch/model/response/pagination'
 
 require 'elasticsearch/model/version'
 
+if defined?(::Kaminari)
+  Elasticsearch::Model::Response::Response.__send__ :include, Elasticsearch::Model::Response::Pagination::Kaminari
+end
+
 module Elasticsearch
 
   # Elasticsearch integration for Ruby models

Diff for: elasticsearch-model/lib/elasticsearch/model/response/pagination.rb

@@ -0,0 +1,87 @@
+module Elasticsearch
+  module Model
+    module Response
+
+      # Pagination for search results/records
+      #
+      module Pagination
+        # Allow models to be paginated with the "kaminari" gem [https://github.com/amatsuda/kaminari]
+        #
+        module Kaminari
+          def self.included(base)
+            # Include the Kaminari modules: Configuration and paging
+            #
+            base.__send__ :include, ::Kaminari::ConfigurationMethods::ClassMethods
+            base.__send__ :include, ::Kaminari::PageScopeMethods
+
+            base.class_eval <<-RUBY, __FILE__, __LINE__ + 1
+              # Define the `page` Kaminari method
+              #
+              def #{::Kaminari.config.page_method_name}(num=nil)
+                @results  = nil
+                @records  = nil
+                @response = nil
+                self.search.definition.update size: klass.default_per_page,
+                                              from: klass.default_per_page * ([num.to_i, 1].max - 1)
+                self
+              end
+            RUBY
+          end
+
+          # Returns the current "limit" (`size`) value
+          #
+          def limit_value
+            case
+              when search.definition[:body] && search.definition[:body][:size]
+                search.definition[:body][:size]
+              when search.definition[:size]
+                search.definition[:size]
+              else
+                0
+            end
+          end
+
+          # Returns the current "offset" (`from`) value
+          #
+          def offset_value
+            case
+              when search.definition[:body] && search.definition[:body][:from]
+                search.definition[:body][:from]
+              when search.definition[:from]
+                search.definition[:from]
+              else
+                0
+            end
+          end
+
+          # Set the "limit" (`size`) value
+          #
+          def limit(value)
+            @results  = nil
+            @records  = nil
+            @response = nil
+            search.definition.update :size => value
+            self
+          end
+
+          # Set the "offset" (`from`) value
+          #
+          def offset(value)
+            @results  = nil
+            @records  = nil
+            @response = nil
+            search.definition.update :from => value
+            self
+          end
+
+          # Returns the total number of results
+          #
+          def total_count
+            results.total
+          end
+        end
+      end
+
+    end
+  end
+end

Diff for: elasticsearch-model/test/test_helper.rb

@@ -20,6 +20,9 @@
 
 require 'active_record'
 require 'active_model'
+
+require 'kaminari'
+
 require 'elasticsearch/model'
 
 require 'elasticsearch/extensions/test/cluster'

Diff for: elasticsearch-model/test/unit/response_pagination_test.rb

@@ -0,0 +1,140 @@
+require 'test_helper'
+
+class Elasticsearch::Model::ResponsePaginationTest < Test::Unit::TestCase
+  context "Response pagination" do
+    class ModelClass
+      include ::Kaminari::ConfigurationMethods
+
+      def self.index_name;    'foo'; end
+      def self.document_type; 'bar'; end
+    end
+
+    RESPONSE = { 'took' => '5', 'timed_out' => false, '_shards' => {'one' => 'OK'},
+                 'hits' => { 'total' => 100, 'hits' => [ {'_id' => 1} ] } }
+
+    setup do
+      search    = Elasticsearch::Model::Searching::SearchRequest.new ModelClass, '*'
+      @response = Elasticsearch::Model::Response::Response.new ModelClass, search, RESPONSE
+      @response.klass.stubs(:client).returns mock('client')
+    end
+
+    should "have pagination methods" do
+      assert_respond_to @response, :page
+      assert_respond_to @response, :limit_value
+      assert_respond_to @response, :offset_value
+      assert_respond_to @response, :limit
+      assert_respond_to @response, :offset
+      assert_respond_to @response, :total_count
+    end
+
+    context "#page method" do
+      should "advance the from/size" do
+        @response.klass.client
+          .expects(:search)
+            .with do |definition|
+              assert_equal 25, definition[:from]
+              assert_equal 25, definition[:size]
+            end
+          .returns(RESPONSE)
+
+        assert_nil @response.search.definition[:from]
+        assert_nil @response.search.definition[:size]
+
+        @response.page(2).to_a
+        assert_equal 25, @response.search.definition[:from]
+        assert_equal 25, @response.search.definition[:size]
+      end
+
+      should "advance the from/size further" do
+        @response.klass.client
+          .expects(:search)
+            .with do |definition|
+              assert_equal 75, definition[:from]
+              assert_equal 25, definition[:size]
+            end
+          .returns(RESPONSE)
+
+        @response.page(4).to_a
+        assert_equal 75, @response.search.definition[:from]
+        assert_equal 25, @response.search.definition[:size]
+      end
+    end
+
+    context "limit/offset readers" do
+      should "return the default" do
+        assert_equal 0, @response.limit_value
+        assert_equal 0, @response.offset_value
+      end
+
+      should "return the value from URL parameters" do
+        search    = Elasticsearch::Model::Searching::SearchRequest.new ModelClass, '*', size: 10, from: 50
+        @response = Elasticsearch::Model::Response::Response.new ModelClass, search, RESPONSE
+
+        assert_equal 10, @response.limit_value
+        assert_equal 50, @response.offset_value
+      end
+
+      should "return the value from body" do
+        search    = Elasticsearch::Model::Searching::SearchRequest.new ModelClass, { query: { match_all: {} }, from: 10, size: 50 }
+        @response = Elasticsearch::Model::Response::Response.new ModelClass, search, RESPONSE
+
+        assert_equal 50, @response.limit_value
+        assert_equal 10, @response.offset_value
+      end
+    end
+
+    context "limit setter" do
+      setup do
+        @response.records
+        @response.results
+      end
+
+      should "set the values" do
+        @response.limit(35)
+        assert_equal 35, @response.search.definition[:size]
+      end
+
+      should "reset the variables" do
+        assert_not_nil @response.instance_variable_get(:@response)
+        assert_not_nil @response.instance_variable_get(:@records)
+        assert_not_nil @response.instance_variable_get(:@results)
+
+        @response.limit(35)
+
+        assert_nil @response.instance_variable_get(:@response)
+        assert_nil @response.instance_variable_get(:@records)
+        assert_nil @response.instance_variable_get(:@results)
+      end
+    end
+
+    context "offset setter" do
+      setup do
+        @response.records
+        @response.results
+      end
+
+      should "set the values" do
+        @response.offset(15)
+        assert_equal 15, @response.search.definition[:from]
+      end
+
+      should "reset the variables" do
+        assert_not_nil @response.instance_variable_get(:@response)
+        assert_not_nil @response.instance_variable_get(:@records)
+        assert_not_nil @response.instance_variable_get(:@results)
+
+        @response.offset(35)
+
+        assert_nil @response.instance_variable_get(:@response)
+        assert_nil @response.instance_variable_get(:@records)
+        assert_nil @response.instance_variable_get(:@results)
+      end
+    end
+
+    context "total" do
+      should "return the number of hits" do
+        assert_equal 100, @response.total_count
+      end
+    end
+  end
+end