Added support for ValueConverter. Preparing for 3.0.0.rc1 release. (#52)

* Added support for ValueConverter.

* Updated to version 3.0.0-rc.1

Author: sdanyliv

Source/LinqToDB.EntityFrameworkCore/EFCoreMetadataReader.cs

@@ -111,6 +111,9 @@ static bool CompareProperty(MemberInfo property, MemberInfo memberInfo)
 		{
 			if (property == memberInfo)
 				return true;
+
+			if (property == null)
+				return false;
 
 			if (memberInfo.DeclaringType?.IsAssignableFrom(property.DeclaringType) == true
 			    && memberInfo.Name == property.Name 
@@ -214,9 +217,8 @@ public T[] GetAttributes<T>(Type type, MemberInfo memberInfo, bool inherit = tru
 
 					return associations.Select(a => (T)(Attribute)a).ToArray();
 				}
-			}
-
-			if (typeof(T) == typeof(Sql.ExpressionAttribute))
+			} 
+			else if (typeof(T) == typeof(Sql.ExpressionAttribute))
 			{
 				// Search for translator first
 				if (_dependencies != null)
@@ -260,10 +262,47 @@ public T[] GetAttributes<T>(Type type, MemberInfo memberInfo, bool inherit = tru
 					}).ToArray();
 				}
 			}
+			else if (typeof(T) == typeof(ValueConverterAttribute))
+			{
+				var et = _model?.FindEntityType(type);
+				if (et != null)
+				{
+					var props = et.GetProperties();
+					var prop  = props.FirstOrDefault(p => CompareProperty(p, memberInfo));
+
+					var converter = prop?.GetValueConverter();
+					if (converter != null)
+					{
+						var valueConverterAttribute = new ValueConverterAttribute
+						{
+							ValueConverter = new ValueConverter(converter.ConvertToProviderExpression,
+								converter.ConvertFromProviderExpression, false)
+						};
+						return new T[] { (T) (Attribute) valueConverterAttribute };
+					}
+				}
+			}
 
 			return Array.Empty<T>();
 		}
 
+		class ValueConverter : IValueConverter
+		{
+			public ValueConverter(
+				LambdaExpression convertToProviderExpression,
+				LambdaExpression convertFromProviderExpression, bool handlesNulls)
+			{
+				FromProviderExpression = convertFromProviderExpression;
+				ToProviderExpression   = convertToProviderExpression;
+				HandlesNulls           = handlesNulls;
+			}
+
+			public bool             HandlesNulls           { get; }
+			public LambdaExpression FromProviderExpression { get; }
+			public LambdaExpression ToProviderExpression   { get; }
+		
+		}
+
 		class SqlTransparentExpression : SqlExpression
 		{
 			public Expression Expression { get; }
@@ -329,7 +368,9 @@ private Sql.ExpressionAttribute GetDbFunctionFromProperty(Type type, PropertyInf
 			{
 				EFCoreExpressionAttribute result = null;
 
-				if ((propInfo.GetMethod?.IsStatic != true) && !mi.GetCustomAttributes<Sql.ExpressionAttribute>().Any())
+				if ((propInfo.GetMethod?.IsStatic != true) 
+				    && !(mi is DynamicColumnInfo) 
+				    && !mi.GetCustomAttributes<Sql.ExpressionAttribute>().Any())
 				{
 					var objExpr = new SqlTransparentExpression(Expression.Constant(DefaultValue.GetValue(type), type), _mappingSource?.FindMapping(propInfo));
 

Source/LinqToDB.EntityFrameworkCore/linq2db.EntityFrameworkCore.csproj

@@ -9,7 +9,7 @@
 	</PropertyGroup>
 
 	<ItemGroup>
-		<PackageReference Include="linq2db" Version="3.0.0-rc.0" />
+		<PackageReference Include="linq2db" Version="3.0.0-rc.1" />
 		<PackageReference Include="Microsoft.EntityFrameworkCore.Relational" Version="3.1.3" />
 	</ItemGroup>
 

Tests/LinqToDB.EntityFrameworkCore.BaseTests/LinqToDB.EntityFrameworkCore.BaseTests.csproj

@@ -11,6 +11,7 @@
 	</ItemGroup>
 
 	<ItemGroup>
+		<PackageReference Include="linq2db" Version="3.0.0-rc.2322" />
 		<PackageReference Include="Microsoft.EntityFrameworkCore.InMemory" Version="3.1.3" />
 		<PackageReference Include="Microsoft.Extensions.Logging" Version="3.1.3" />
 		<PackageReference Include="Microsoft.Extensions.Logging.Console" Version="3.1.3" />

Tests/LinqToDB.EntityFrameworkCore.SqlServer.Tests/JsonConverTests.cs

@@ -90,11 +90,11 @@ public void TestJsonConvert()
 		{
 			LinqToDBForEFTools.Initialize();
 
-			// converting from string, because usually JSON is stored as string, but it depends on DataProvider
-			Mapping.MappingSchema.Default.SetConverter<string, LocalizedString>(v => JsonConvert.DeserializeObject<LocalizedString>(v));
-
-			// here we told linq2db how to pass converted value as DataParameter.
-			Mapping.MappingSchema.Default.SetConverter<LocalizedString, DataParameter>(v => new DataParameter("", JsonConvert.SerializeObject(v), LinqToDB.DataType.NVarChar));
+			// // converting from string, because usually JSON is stored as string, but it depends on DataProvider
+			// Mapping.MappingSchema.Default.SetConverter<string, LocalizedString>(v => JsonConvert.DeserializeObject<LocalizedString>(v));
+			//
+			// // here we told linq2db how to pass converted value as DataParameter.
+			// Mapping.MappingSchema.Default.SetConverter<LocalizedString, DataParameter>(v => new DataParameter("", JsonConvert.SerializeObject(v), LinqToDB.DataType.NVarChar));
 
 			using (var ctx = new JsonConvertContext(_options))
 			{

Tests/LinqToDB.EntityFrameworkCore.SqlServer.Tests/Models/Northwind/NorthwindContext.cs

@@ -57,7 +57,7 @@ private void ConfigureGlobalQueryFilters(ModelBuilder builder)
 				if (typeof(ISoftDelete).IsSameOrParentOf(entityType.ClrType))
 				{
 					var method = ConfigureEntityFilterMethodInfo.MakeGenericMethod(entityType.ClrType);
-					method.Invoke(this, new object?[] { builder });
+					method.Invoke(this, new object[] { builder });
 				}
 			}
 		}

Tests/LinqToDB.EntityFrameworkCore.SqlServer.Tests/ToolsTests.cs

@@ -59,7 +59,7 @@ private void SetIdentityInsert(DbContext ctx, string tableName, bool isOn)
 			var str = $"SET IDENTITY_INSERT {tableName} " + (isOn ? "ON" : "OFF");
 			try
 			{
-				ctx.Database.ExecuteSqlCommand(str);
+				ctx.Database.ExecuteSqlRaw(str);
 			}
 			catch (Exception)
 			{