Supporting the ability to define sort order on the client if it is no…

…t specified on the server

Raven.Database/Extensions/IndexingExtensions.cs

@@ -13,6 +13,7 @@
 using Raven.Abstractions.Data;
 using Raven.Abstractions.Indexing;
 using Raven.Database.Indexing.Sorting;
+using Raven.Database.Server;
 using Constants = Raven.Abstractions.Data.Constants;
 
 namespace Raven.Database.Extensions
@@ -117,16 +118,22 @@ public static Sort GetSort(this IndexQuery self, IndexDefinition indexDefinition
 		public static SortOptions? GetSortOption(this IndexDefinition self, string name)
 		{
 			SortOptions value;
-			if (!self.SortOptions.TryGetValue(name, out value))
+			if (self.SortOptions.TryGetValue(name, out value))
+				return value;
+
+			if (name.EndsWith("_Range"))
 			{
-				if (!name.EndsWith("_Range"))
-				{
-					return null;
-				}
 				string nameWithoutRange = name.Substring(0, name.Length - "_Range".Length);
-				if (!self.SortOptions.TryGetValue(nameWithoutRange, out value))
-					return null;
+				if (self.SortOptions.TryGetValue(nameWithoutRange, out value))
+					return value;
 			}
+			if (CurrentOperationContext.Headers.Value == null)
+				return value;
+
+			var hint = CurrentOperationContext.Headers.Value["SortHint-" + name];
+			if (string.IsNullOrEmpty(hint))
+				return value;
+			Enum.TryParse(hint, true, out value);
 			return value;
 		}
 	}

Raven.Tests/MailingList/DynamicFieldSorting.cs

@@ -47,6 +47,12 @@ public class ProjectionItem
 			{
 				public string SongId { get; set; }
 				public NumericAttribute[] NumericAttributes { get; set; }
+
+				public override string ToString()
+				{
+					return string.Format("SongId: {0}, N1: {1}", SongId,
+						NumericAttributes.First(x => x.Name == "N1").Value);
+				}
 			}
 
 			public WithDynamicIndex()
@@ -72,7 +78,7 @@ select new
 		[Fact]
 		public void CanSortDynamicaly()
 		{
-			using(var store = NewDocumentStore())
+			using (var store = NewDocumentStore())
 			{
 				new WithDynamicIndex().Execute(store);
 				using (var session = store.OpenSession())
@@ -108,6 +114,43 @@ public void CanSortDynamicaly()
 			}
 		}
 
+		[Fact]
+		public void CanSortDynamicaly_Desc()
+		{
+			using (var Store = NewDocumentStore())
+			{
+				new WithDynamicIndex().Execute(Store);
+				using (var session = Store.OpenSession())
+				{
+					session.Store(new DataSet
+					{
+						Items = Enumerable.Range(1, 50).Select(x =>
+									new Item
+									{
+										SongId = "songs/" + x,
+										NumericAttributes = new[]
+									{
+										new NumericAttribute("N1",x*0.99d),
+										new NumericAttribute("N4",x*0.01d),
+									}
+									}).ToList()
+					});
+					session.SaveChanges();
+				}
+
+				using (var s = Store.OpenSession())
+				{
+					var items = s.Advanced.LuceneQuery<WithDynamicIndex.ProjectionItem, WithDynamicIndex>()
+						.WaitForNonStaleResults()
+						.AddOrder("N1_Range", true, typeof(double))
+						.SelectFields<WithDynamicIndex.ProjectionItem>("SongId", "NumericAttributes")
+						.ToList();
+					Assert.Equal(50, items.Count);
+					Assert.Equal("songs/50", items.First().SongId);
+				}
+			}
+		}
+
 	}
 
 }