Add support of base collection with inherited types

Author: mythz

src/ServiceStack.Text/Common/WriteType.cs

@@ -356,14 +356,24 @@ public static void WriteAbstractProperties(TextWriter writer, object value)
                 return;
             }
 
-            var writeFn = Serializer.GetWriteFn(valueType);
-            if (!JsConfig<T>.ExcludeTypeInfo.GetValueOrDefault()) JsState.IsWritingDynamic = true;
-            writeFn(writer, value);
-            if (!JsConfig<T>.ExcludeTypeInfo.GetValueOrDefault()) JsState.IsWritingDynamic = false;
+            WriteLateboundProperties(writer, value, valueType);
         }
 
         public static void WriteProperties(TextWriter writer, object value)
         {
+            if (value == null)
+            {
+                writer.Write(JsWriter.EmptyMap);
+                return;
+            }
+
+            var valueType = value.GetType();
+            if (PropertyWriters != null && valueType != typeof(T) && !typeof(T).IsAbstract())
+            {
+                WriteLateboundProperties(writer, value, valueType);
+                return;
+            }
+
             if (typeof(TSerializer) == typeof(JsonTypeSerializer) && JsState.WritingKeyCount > 0)
                 writer.Write(JsWriter.QuoteChar);
 
@@ -384,7 +394,7 @@ public static void WriteProperties(TextWriter writer, object value)
                 {
                     var propertyWriter = PropertyWriters[index];
 
-                    if (value != null && propertyWriter.shouldSerialize != null && !propertyWriter.shouldSerialize((T)value)) 
+                    if (propertyWriter.shouldSerialize != null && !propertyWriter.shouldSerialize((T)value)) 
                         continue;
 
                     var dontSkipDefault = false;
@@ -400,9 +410,7 @@ public static void WriteProperties(TextWriter writer, object value)
                         }
                     }
 
-                    var propertyValue = value != null
-                        ? propertyWriter.GetterFn((T)value)
-                        : null;
+                    var propertyValue = propertyWriter.GetterFn((T)value);
 
                     if (!dontSkipDefault)
                     {
@@ -444,6 +452,14 @@ public static void WriteProperties(TextWriter writer, object value)
                 writer.Write(JsWriter.QuoteChar);
         }
 
+        private static void WriteLateboundProperties(TextWriter writer, object value, Type valueType)
+        {
+            var writeFn = Serializer.GetWriteFn(valueType);
+            if (!JsConfig<T>.ExcludeTypeInfo.GetValueOrDefault()) JsState.IsWritingDynamic = true;
+            writeFn(writer, value);
+            if (!JsConfig<T>.ExcludeTypeInfo.GetValueOrDefault()) JsState.IsWritingDynamic = false;
+        }
+
         private static readonly char[] ArrayBrackets = new[] { '[', ']' };
 
         public static void WriteComplexQueryStringProperties(string typeName, TextWriter writer, object value)

tests/ServiceStack.Text.Tests/JsonTests/InheritAbstractTests.cs

@@ -0,0 +1,56 @@
+using System;
+using System.Collections.Generic;
+using System.Runtime.Serialization;
+using NUnit.Framework;
+using ServiceStack.Text.Tests.Support;
+
+namespace ServiceStack.Text.Tests.JsonTests
+{
+    [DataContract]
+    public class MovieChild : Movie
+    {
+        public MovieChild()
+        {
+            this.Oscar = new List<string>();
+        }
+
+        [DataMember]
+        public List<string> Oscar { get; set; }
+    }
+
+    class BlockBuster
+    {
+        public BlockBuster(string address)
+        {
+            this.Address = address;
+            this.Movies = new List<Movie>();
+        }
+
+        public string Address { get; set; }
+        public List<Movie> Movies { get; set; }
+    }
+    
+    [TestFixture]
+    public class InheritAbstractTests
+    {
+        [Test]
+        public void Can_serialize_class_with_list_that_classes_inherited_from_non_abstract_class()
+        {
+            var child = new MovieChild { ImdbId = "tt0068646", Title = "The Godfather", Rating = 9.2m, Director = "Francis Ford Coppola", ReleaseDate = new DateTime(1972, 3, 24), TagLine = "An offer you can't refuse.", Genres = new List<string> { "Crime", "Drama", "Thriller" }, };
+            child.Oscar.Add("Best Picture - 1972");
+            child.Oscar.Add("Best Actor - 1972");
+            child.Oscar.Add("Best Adapted Screenplay - 1972");
+
+            var blockBuster = new BlockBuster("Av. República do Líbano, 2175 - Indinópolis, São Paulo - SP, 04502-300");
+            blockBuster.Movies.Add(MoviesData.Movies[0]);
+            blockBuster.Movies.Add(child);
+
+            // serialize to JSON using ServiceStack
+            string jsonString = JsonSerializer.SerializeToString(blockBuster);
+
+            const string expected = "{\"Address\":\"Av. República do Líbano, 2175 - Indinópolis, São Paulo - SP, 04502-300\",\"Movies\":[{\"Title\":\"The Shawshank Redemption\",\"ImdbId\":\"tt0111161\",\"Rating\":9.2,\"Director\":\"Frank Darabont\",\"ReleaseDate\":\"\\/Date(792950400000-0000)\\/\",\"TagLine\":\"Fear can hold you prisoner. Hope can set you free.\",\"Genres\":[\"Crime\",\"Drama\"]},{\"__type\":\"ServiceStack.Text.Tests.JsonTests.MovieChild, ServiceStack.Text.Tests\",\"Oscar\":[\"Best Picture - 1972\",\"Best Actor - 1972\",\"Best Adapted Screenplay - 1972\"],\"Title\":\"The Godfather\",\"ImdbId\":\"tt0068646\",\"Rating\":9.2,\"Director\":\"Francis Ford Coppola\",\"ReleaseDate\":\"\\/Date(70214400000-0000)\\/\",\"TagLine\":\"An offer you can't refuse.\",\"Genres\":[\"Crime\",\"Drama\",\"Thriller\"]}]}";
+
+            Assert.That(jsonString, Is.EqualTo(expected));
+        }
+    }
+}

tests/ServiceStack.Text.Tests/ServiceStack.Text.Tests.csproj

@@ -180,6 +180,7 @@
     <Compile Include="AttributeTests.cs" />
     <Compile Include="CsvTypeTests.cs" />
     <Compile Include="HttpUtilsTests.cs" />
+    <Compile Include="JsonTests\InheritAbstractTests.cs" />
     <Compile Include="JsonTests\JsonEnumTests.cs" />
     <Compile Include="JsonTests\InvalidJsonTests.cs" />
     <Compile Include="JsonTests\OnDeserializationErrorTests.cs" />