Merge branch 'scroll-fix'

Author: bytenik

src/Nest/DSL/ScrollDescriptor.cs

@@ -9,6 +9,7 @@ public interface IScrollRequest : IRequest<ScrollRequestParameters>
 	{
 		string ScrollId { get; set; }
 		string Scroll { get; set; }
+	    Func<object, Hit<object>, Type> TypeSelector { get; set; }
 	}
 
 	internal static class ScrollPathInfo
@@ -31,8 +32,9 @@ public partial class ScrollRequest : BaseRequest<ScrollRequestParameters>, IScro
 	{
 		public string ScrollId { get; set; }
 		public string Scroll { get; set; }
+        public Func<object, Hit<object>, Type> TypeSelector { get; set; }
 
-		public ScrollRequest(string scrollId, string scrollTimeout)
+        public ScrollRequest(string scrollId, string scrollTimeout)
 		{
 			this.ScrollId = scrollId;
 			this.Scroll = scrollTimeout;
@@ -57,9 +59,10 @@ protected override void UpdatePathInfo(IConnectionSettingsValues settings, Elast
 
 		string IScrollRequest.ScrollId { get; set; }
 		string IScrollRequest.Scroll { get; set; }
-		
-		///<summary>Specify how long a consistent view of the index should be maintained for scrolled search</summary>
-		public ScrollDescriptor<T> Scroll(string scroll)
+        Func<object, Hit<object>, Type> IScrollRequest.TypeSelector { get; set; }
+
+        ///<summary>Specify how long a consistent view of the index should be maintained for scrolled search</summary>
+        public ScrollDescriptor<T> Scroll(string scroll)
 		{
 			Self.Scroll = scroll;
 			return this;
@@ -71,5 +74,11 @@ public ScrollDescriptor<T> ScrollId(string scrollId)
 			Self.ScrollId = scrollId;
 			return this;
 		}
-	}
+
+        public ScrollDescriptor<T> ConcreteTypeSelector(Func<dynamic, Hit<dynamic>, Type> typeSelector)
+        {
+            Self.TypeSelector = typeSelector;
+            return this;
+        }
+    }
 }

src/Nest/ElasticClient-Scroll.cs

@@ -1,6 +1,8 @@
 using System;
+using System.IO;
 using System.Threading.Tasks;
 using Elasticsearch.Net;
+using Newtonsoft.Json;
 
 namespace Nest
 {
@@ -56,7 +58,9 @@ public Task<ISearchResponse<T>> ScrollAsync<T>(Func<ScrollDescriptor<T>, ScrollD
 				{
 					string scrollId = p.ScrollId;
 					p.ScrollId = null;
-					return this.RawDispatch.ScrollDispatchAsync<SearchResponse<T>>(p, scrollId);
+				    p.DeserializationState(CreateScrollDeserializer<T, T>(d));
+
+                    return this.RawDispatch.ScrollDispatchAsync<SearchResponse<T>>(p, scrollId);
 				}
 			);
 		}
@@ -126,5 +130,26 @@ private static string PatchClearScroll(ElasticsearchPathInfo<ClearScrollRequestP
 			}
 			return body;
 		}
-	}
+
+        private SearchResponse<TResult> FieldsScrollDeserializer<T, TResult>(IElasticsearchResponse response, Stream stream, IScrollRequest d)
+            where T : class
+            where TResult : class
+        {
+            var converter = d.TypeSelector == null ? null : new ConcreteTypeConverter<TResult>(d.TypeSelector);
+            var dict = response.Success
+                ? Serializer.DeserializeInternal<SearchResponse<TResult>>(stream, converter)
+                : null;
+            return dict;
+        }
+
+        private Func<IElasticsearchResponse, Stream, SearchResponse<TResult>> CreateScrollDeserializer<T, TResult>(IScrollRequest request)
+            where T : class
+            where TResult : class
+        {
+
+            Func<IElasticsearchResponse, Stream, SearchResponse<TResult>> responseCreator =
+                    (r, s) => this.FieldsScrollDeserializer<T, TResult>(r, s, request);
+            return responseCreator;
+        }
+    }
 }