[MODEL] Added "default per page" methods for pagination with multi model searches

Due to the fact that different models aggregated on a multimodel search could have different default values for the page size. I have opted for defaulting to Kaminari's and WillPaginate's respective default values.

Problem:

    Elasticsearch::Model.search(query, [AAA, BBB]).page(1).results
    NoMethodError:
    undefined method `default_per_page' for #Elasticsearch::Model::Multimodel:0x007ff9dbe4f520

Fixes  elastic#382
Closes elastic#408

Author: miguelff

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

@@ -31,7 +31,7 @@ def #{::Kaminari.config.page_method_name}(num=nil)
                 @records  = nil
                 @response = nil
                 @page     = [num.to_i, 1].max
-                @per_page ||= klass.default_per_page
+                @per_page ||= __default_per_page
 
                 self.search.definition.update size: @per_page,
                                               from: @per_page * (@page - 1)
@@ -48,7 +48,7 @@ def limit_value
               when search.definition[:size]
                 search.definition[:size]
               else
-                search.klass.default_per_page
+                __default_per_page
             end
           end
 
@@ -94,6 +94,14 @@ def offset(value)
           def total_count
             results.total
           end
+
+          # Returns the models's `per_page` value or the default
+          #
+          # @api private
+          #
+          def __default_per_page
+            klass.respond_to?(:default_per_page) && klass.default_per_page || ::Kaminari.config.default_per_page
+          end
         end
 
         # Allow models to be paginated with the "will_paginate" gem [https://github.com/mislav/will_paginate]
@@ -126,7 +134,7 @@ def length
           def paginate(options)
             param_name = options[:param_name] || :page
             page       = [options[param_name].to_i, 1].max
-            per_page   = (options[:per_page] || klass.per_page).to_i
+            per_page   = (options[:per_page] || __default_per_page).to_i
 
             search.definition.update size: per_page,
                                      from: (page - 1) * per_page
@@ -168,6 +176,14 @@ def per_page(num = nil)
           def total_entries
             results.total
           end
+
+          # Returns the models's `per_page` value or the default
+          #
+          # @api private
+          #
+          def __default_per_page
+            klass.respond_to?(:per_page) && klass.per_page || ::WillPaginate.per_page
+          end
         end
       end
 

elasticsearch-model/test/unit/response_pagination_kaminari_test.rb

@@ -1,16 +1,17 @@
 require 'test_helper'
 
 class Elasticsearch::Model::ResponsePaginationKaminariTest < Test::Unit::TestCase
-  context "Response pagination" do
-    class ModelClass
-      include ::Kaminari::ConfigurationMethods
+  class ModelClass
+    include ::Kaminari::ConfigurationMethods
 
-      def self.index_name;    'foo'; end
-      def self.document_type; 'bar'; end
-    end
+    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' => (1..100).to_a.map { |i| { _id: i } } } }
+  RESPONSE = { 'took' => '5', 'timed_out' => false, '_shards' => {'one' => 'OK'},
+               'hits' => { 'total' => 100, 'hits' => (1..100).to_a.map { |i| { _id: i } } } }
+
+  context "Response pagination" do
 
     setup do
       @search   = Elasticsearch::Model::Searching::SearchRequest.new ModelClass, '*'
@@ -208,4 +209,181 @@ def self.document_type; 'bar'; end
       end
     end
   end
+
+  context "Multimodel response pagination" do
+    setup do
+      @multimodel = Elasticsearch::Model::Multimodel.new(ModelClass)
+      @search     = Elasticsearch::Model::Searching::SearchRequest.new @multimodel, '*'
+      @response   = Elasticsearch::Model::Response::Response.new @multimodel, @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]
+          true
+        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]
+          true
+        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 Kaminari.config.default_per_page, @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 "ignore the value from request body" do
+        search    = Elasticsearch::Model::Searching::SearchRequest.new ModelClass,
+                                                                       { query: { match_all: {} }, from: 333, size: 999 }
+        @response = Elasticsearch::Model::Response::Response.new ModelClass, search, RESPONSE
+
+        assert_equal Kaminari.config.default_per_page, @response.limit_value
+        assert_equal 0, @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
+        @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 "with the page() and limit() methods" do
+      setup do
+        @response.records
+        @response.results
+      end
+
+      should "set the values" do
+        @response.page(3).limit(35)
+        assert_equal 35, @response.search.definition[:size]
+        assert_equal 70, @response.search.definition[:from]
+      end
+
+      should "set the values when limit is called first" do
+        @response.limit(35).page(3)
+        assert_equal 35, @response.search.definition[:size]
+        assert_equal 70, @response.search.definition[:from]
+      end
+
+      should "reset the instance variables" do
+        @response.page(3).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
+        @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
+        @response.expects(:results).returns(mock('results', total: 100))
+        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