Adding support for recursion in indexes

ravendb · Sep 20, 2011 · 6c25bbf · 6c25bbf
1 parent 3c60af6
commit 6c25bbf
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Showing 4 changed files with 123 additions and 0 deletions.
diff --git a/Raven.Client.Lightweight/Indexes/AbstractIndexCreationTask.cs b/Raven.Client.Lightweight/Indexes/AbstractIndexCreationTask.cs
@@ -49,6 +49,14 @@ public abstract class AbstractIndexCreationTask
 		public DocumentConvention Conventions { get; set; }
 
 #if !NET_3_5
+		/// <summary>
+		/// Allows to use lambdas recursively
+		/// </summary>
+		protected IEnumerable<TResult> Recurse<TSource,TResult>(TSource source, Func<TSource, TResult> func)
+		{
+			throw new NotSupportedException("This can only be run on the server side");
+		}
+
 		/// <summary>
 		/// Allows to use lambdas over dynamic
 		/// </summary>

diff --git a/Raven.Database/Linq/AbstractViewGenerator.cs b/Raven.Database/Linq/AbstractViewGenerator.cs
@@ -113,6 +113,27 @@ protected IEnumerable<dynamic> Hierarchy(object source, string name)
 			}
 		}
 
+		protected IEnumerable<dynamic> Recurse(object item, Func<dynamic ,dynamic> func)
+		{
+			if (item == null)
+				return Enumerable.Empty<dynamic>();
+
+			var resultsOrdered = new List<dynamic>();
+
+			var results = new HashSet<object>();
+			item = func(item);
+			while (item != null)
+			{
+				if (results.Add(item) == false)
+					break;
+
+				resultsOrdered.Add(item);
+				item = func(item);
+			}
+
+			return new DynamicJsonObject.DynamicList(resultsOrdered.ToArray());
+		}
+
 		public void AddQueryParameterForMap(string field)
 		{
 			mapFields.Add(field);

diff --git a/Raven.Tests/Bugs/RecursiveQueries.cs b/Raven.Tests/Bugs/RecursiveQueries.cs
@@ -0,0 +1,93 @@
+using System.Collections.Generic;
+using System.Linq;
+using Raven.Client.Indexes;
+using Xunit;
+using Raven.Client.Linq;
+
+namespace Raven.Tests.Bugs
+{
+	public class RecursiveQueries : RavenTest
+	{
+		[Fact]
+		public void ShouldBePossible()
+		{
+			using(var store = NewDocumentStore())
+			{
+				new CategoryWithParentsAndChildren().Execute(store);
+
+				using(var session = store.OpenSession())
+				{
+					var root = new Category
+					{
+						Name = "Root"
+					};
+					session.Store(root);
+					var category = new Category
+					{
+						Name = "Child",
+						ParentId = root.Id
+					};
+					session.Store(category);
+					session.Store(new Category
+					{
+						Name = "Grandchild",
+						ParentId = category.Id
+					});
+					session.SaveChanges();
+				}
+
+				using(var session = store.OpenSession())
+				{
+					List<CategoryHeaderWithParents> categoryHeaderWithParentses = session.Query<CategoryHeaderWithParents, CategoryWithParentsAndChildren>()
+						.Customize(x=>x.WaitForNonStaleResults())
+						.Where(x=>x.Name == "Grandchild")
+						.ToList();
+
+					Assert.Equal("Grandchild", categoryHeaderWithParentses[0].Name);
+					Assert.Equal("Child", categoryHeaderWithParentses[0].Parents[0].Name);
+					Assert.Equal("Root", categoryHeaderWithParentses[0].Parents[1].Name);
+				}
+			}
+		}
+
+		public class CategoryWithParentsAndChildren : AbstractIndexCreationTask<Category>
+		{
+			public CategoryWithParentsAndChildren()
+			{
+				Map = categories => from category in categories
+				                    select new {category.Id, category.Name, category.ParentId};
+				TransformResults = (database, categories) =>
+				                   from category in categories
+								   let parentCategories = Recurse(category, c => database.Load<Category>(c.ParentId))
+				                   select new
+				                   {
+				                   	category.Id,
+				                   	category.Name,
+				                   	Parents =
+				                   	(
+				                   		from parent in parentCategories
+				                   		select new {parent.Id, parent.Name}
+				                   	)
+				                   };
+			}
+		}
+
+		public class CategoryHeader
+		{
+			public string Id { get; set; }
+			public string Name { get; set; }
+		}
+
+		public class CategoryHeaderWithParents : CategoryHeader
+		{
+			public CategoryHeader[] Parents { get; set; }
+		}
+
+		public class Category
+		{
+			public string Id { get; set; }
+			public string Name { get; set; }
+			public string ParentId { get; set; }
+		}
+	}
+}
diff --git a/Raven.Tests/Raven.Tests.csproj b/Raven.Tests/Raven.Tests.csproj
@@ -205,6 +205,7 @@
     <Compile Include="Bugs\QueryingOnEmptyString.cs" />
     <Compile Include="Bugs\QueryOptimizerOnStaticIndex.cs" />
     <Compile Include="Bugs\RacielrodTest.cs" />
+    <Compile Include="Bugs\RecursiveQueries.cs" />
     <Compile Include="Bugs\RoundCrisis.cs" />
     <Compile Include="Bugs\SelfReference.cs" />
     <Compile Include="Bugs\SerializingAndDeserializingWithRaven.cs" />