Merge pull request #19 from roji/roundtrip_ctor

Can roundrip with type converter and no default ctor

YamlDotNet.RepresentationModel/Serialization/FullObjectGraphTraversalStrategy.cs

@@ -13,15 +13,17 @@ namespace YamlDotNet.RepresentationModel.Serialization
 	/// </summary>
 	public class FullObjectGraphTraversalStrategy : IObjectGraphTraversalStrategy
 	{
+		protected readonly Serializer serializer;
 		private readonly int maxRecursion;
 
-		public FullObjectGraphTraversalStrategy(int maxRecursion)
+		public FullObjectGraphTraversalStrategy(Serializer serializer, int maxRecursion)
 		{
 			if(maxRecursion <= 0)
 			{
 				throw new ArgumentOutOfRangeException("maxRecursion", maxRecursion, "maxRecursion must be greater than 1");
 			}
 
+			this.serializer = serializer;
 			this.maxRecursion = maxRecursion;
 		}
 

YamlDotNet.RepresentationModel/Serialization/RoundtripObjectGraphTraversalStrategy.cs

@@ -1,5 +1,6 @@
 using System;
 using System.Globalization;
+using System.Linq;
 using System.Reflection;
 
 namespace YamlDotNet.RepresentationModel.Serialization
@@ -22,16 +23,16 @@ namespace YamlDotNet.RepresentationModel.Serialization
 		//    base.TraverseObject(value, type, visitor);
 		//}
 
-		public RoundtripObjectGraphTraversalStrategy(int maxRecursion)
-			: base(maxRecursion)
+		public RoundtripObjectGraphTraversalStrategy(Serializer serializer, int maxRecursion)
+			: base(serializer, maxRecursion)
 		{
 		}
 
 		protected override void SerializeProperties(object value, Type type, IObjectGraphVisitor visitor, int currentDepth)
 		{
-			if (!ReflectionUtility.HasDefaultConstructor(type))
+			if (!ReflectionUtility.HasDefaultConstructor(type) && !serializer.Converters.Any(c => c.Accepts(type)))
 			{
-				throw new InvalidOperationException(string.Format(CultureInfo.InvariantCulture, "Type '{0}' cannot be deserialized because it does not have a default constructor.", type));
+				throw new InvalidOperationException(string.Format(CultureInfo.InvariantCulture, "Type '{0}' cannot be deserialized because it does not have a default constructor or a type converter.", type));
 			}
 
 			base.SerializeProperties(value, type, visitor, currentDepth);

YamlDotNet.RepresentationModel/Serialization/Serializer.cs

@@ -71,14 +71,19 @@ namespace YamlDotNet.RepresentationModel.Serialization
 	/// </summary>
 	public sealed class Serializer
 	{
-		private readonly IList<IYamlTypeConverter> converters = new List<IYamlTypeConverter>();
+		internal IList<IYamlTypeConverter> Converters { get; private set; }
+
+		public Serializer()
+		{
+			Converters = new List<IYamlTypeConverter>();
+		}
 
 		/// <summary>
 		/// Registers a type converter to be used to serialize and deserialize specific types.
 		/// </summary>
 		public void RegisterTypeConverter(IYamlTypeConverter converter)
 		{
-			converters.Add(converter);
+			Converters.Add(converter);
 		}
 
 		/// <summary>
@@ -155,7 +160,7 @@ namespace YamlDotNet.RepresentationModel.Serialization
 		{
 			IObjectGraphVisitor emittingVisitor = new EmittingObjectGraphVisitor(eventEmitter);
 
-			emittingVisitor = new CustomSerializationObjectGraphVisitor(emitter, emittingVisitor, converters);
+			emittingVisitor = new CustomSerializationObjectGraphVisitor(emitter, emittingVisitor, Converters);
 
 			if ((options & SerializationOptions.DisableAliases) == 0)
 			{
@@ -191,11 +196,11 @@ namespace YamlDotNet.RepresentationModel.Serialization
 		{
 			if ((options & SerializationOptions.Roundtrip) != 0)
 			{
-				return new RoundtripObjectGraphTraversalStrategy(50);
+				return new RoundtripObjectGraphTraversalStrategy(this, 50);
 			}
 			else
 			{
-				return new FullObjectGraphTraversalStrategy(50);
+				return new FullObjectGraphTraversalStrategy(this, 50);
 			}
 		}
 	}

YamlDotNet.UnitTests/RepresentationModel/SerializationTests.cs

@@ -23,6 +23,7 @@ using System;
 using System.Drawing;
 using Xunit;
 using System.IO;
+using YamlDotNet.Core;
 using YamlDotNet.RepresentationModel.Serialization;
 using System.Reflection;
 using System.Collections;
@@ -554,15 +555,47 @@ namespace YamlDotNet.UnitTests.RepresentationModel
 			#endregion
 		}
 
-		//[Fact]
-		//public void DeserializeTypeConverter()
-		//{
-		//    YamlSerializer<Z> serializer = new YamlSerializer<Z>();
-		//    object result = serializer.Deserialize(YamlFile("converter.yaml"));
+		class SomeCustomeType
+		{
+			// Test specifically with no parameterless, supposed to fail unless a type converter is specified
+			public SomeCustomeType(string value) { Value = value; }
+			public string Value;
+		}
 
-		//    Assert.True(typeof(Z).IsAssignableFrom(result.GetType()));
-		//    Assert.Equal("[hello, world]", ((Z)result).aaa, "The property has the wrong value.");
-		//}
+		public class CustomTypeConverter : IYamlTypeConverter
+		{
+			public bool Accepts(Type type) { return type == typeof(SomeCustomeType); }
+
+			public object ReadYaml(Parser parser, Type type)
+			{
+				var value = ((Scalar)parser.Current).Value;
+				parser.MoveNext();
+				return new SomeCustomeType(value);
+			}
+
+			public void WriteYaml(Emitter emitter, object value, Type type)
+			{
+				emitter.Emit(new Scalar(((SomeCustomeType)value).Value));
+			}
+		}
+
+		[Fact]
+		public void RoundtripWithTypeConverter()
+		{
+			SomeCustomeType x = new SomeCustomeType("Yo");
+			var serializer = new Serializer();
+			serializer.RegisterTypeConverter(new CustomTypeConverter());
+			StringWriter buffer = new StringWriter();
+			serializer.Serialize(buffer, x, SerializationOptions.Roundtrip);
+
+			Console.WriteLine(buffer.ToString());
+
+			var deserializer = new YamlSerializer<SomeCustomeType>(YamlSerializerModes.Roundtrip);
+			deserializer.RegisterTypeConverter(new CustomTypeConverter());
+
+			var copy = deserializer.Deserialize(new StringReader(buffer.ToString()));
+			Assert.Equal("Yo", copy.Value);
+		}
 
 		[Fact]
 		public void RoundtripDictionary()