moved conversion into a different project.

PoweredSoft.Conversion/Convert.cs

@@ -0,0 +1,58 @@
+using PoweredSoft.Types.Converters;
+using PoweredSoft.Types.Interface;
+using System;
+using System.Collections.Generic;
+using System.Linq;
+using System.Text;
+
+namespace PoweredSoft.Types
+{
+    public static class Converter
+    {
+        public static List<ITypeConverter> Converters { get; internal set; } = new List<ITypeConverter>
+        {
+            new StringToDateConverter(),
+            new StringToGuidConverter()
+        };
+
+        public static void RegisterConverter(ITypeConverter converter)
+        {
+            lock (Converters)
+            {
+                Converters.Add(converter);
+            }
+        }
+
+        public static void ReplaceConverter(ITypeConverter converter, Type source, Type destination)
+        {
+            lock (Converters)
+            {
+                Converters.RemoveAll(t => t.CanConvert(source, destination));
+                Converters.Add(converter);
+            }
+        }
+
+        public static object To(this object source, Type type)
+        {
+            object ret = null;
+
+            // safe if null.
+            if (source == null)
+                return ret;
+
+            // establish final type.
+            var notNullType = Nullable.GetUnderlyingType(type);
+            var finalType = notNullType ?? type;
+            var converter = Converters.FirstOrDefault(t => t.CanConvert(source.GetType(), finalType));
+            if (converter != null)
+                ret = converter.Convert(source, finalType);
+            else
+                ret = Convert.ChangeType(source, finalType);
+
+            if (notNullType != null)
+                ret = Activator.CreateInstance(type, new object[] { ret });
+
+            return ret;
+        }
+    }
+}

PoweredSoft.Conversion/Converters/StringToDateConverter.cs

@@ -0,0 +1,13 @@
+using PoweredSoft.Types.Interface;
+using System;
+using System.Collections.Generic;
+using System.Text;
+
+namespace PoweredSoft.Types.Converters
+{
+    public class StringToDateConverter : ITypeConverter
+    {
+        public bool CanConvert(Type source, Type destination) => source == typeof(string) && destination == typeof(DateTime);
+        public object Convert(object source, Type destination) => DateTime.Parse((string)source);
+    }
+}

PoweredSoft.Conversion/Converters/StringToGuidConverter.cs

@@ -0,0 +1,13 @@
+using PoweredSoft.Types.Interface;
+using System;
+using System.Collections.Generic;
+using System.Text;
+
+namespace PoweredSoft.Types.Converters
+{
+    public class StringToGuidConverter : ITypeConverter
+    {
+        public bool CanConvert(Type source, Type destination) => source == typeof(string) && destination == typeof(Guid);
+        public object Convert(object source, Type destination) => Guid.Parse((string)source);
+    }
+}

PoweredSoft.Conversion/Interface/ITypeConverter.cs

@@ -0,0 +1,12 @@
+using System;
+using System.Collections.Generic;
+using System.Text;
+
+namespace PoweredSoft.Types.Interface
+{
+    public interface ITypeConverter
+    {
+        bool CanConvert(Type source, Type destination);
+        object Convert(object source, Type destination);
+    }
+}

PoweredSoft.Conversion/PoweredSoft.Types.csproj

@@ -0,0 +1,7 @@
+<Project Sdk="Microsoft.NET.Sdk">
+
+  <PropertyGroup>
+    <TargetFramework>netstandard2.0</TargetFramework>
+  </PropertyGroup>
+
+</Project>

PoweredSoft.DynamicLinq.Dal/BlogContext.cs

@@ -37,6 +37,8 @@ namespace PoweredSoft.DynamicLinq.Dal
             modelBuilder.Configurations.Add(new CommentConfiguration());
             modelBuilder.Configurations.Add(new PostConfiguration());
             modelBuilder.Configurations.Add(new WebsiteConfiguration());
+            modelBuilder.Configurations.Add(new CommentLikeConfiguration());
+            modelBuilder.Configurations.Add(new UniqueConfiguration());
         }
     }
 }

PoweredSoft.DynamicLinq.Dal/Configurations/Configurations.cs

@@ -9,6 +9,23 @@ using System.Threading.Tasks;
 
 namespace PoweredSoft.DynamicLinq.Dal.Configurations
 {
+    public class UniqueConfiguration : EntityTypeConfiguration<Unique>
+    {
+        public UniqueConfiguration() : this("dbo")
+        {
+
+        }
+
+        public UniqueConfiguration(string schema)
+        {
+            ToTable("Unique", schema);
+            HasKey(t => t.Id);
+            Property(t => t.Id).HasColumnName("Id").HasColumnType("bigint").IsRequired().HasDatabaseGeneratedOption(DatabaseGeneratedOption.Identity);
+            Property(t => t.RowNumber).HasColumnType("uniqueidentifier").IsRequired();
+            Property(t => t.OtherNullableGuid).HasColumnType("uniqueidentifier");
+        }
+    }
+
     public class AuthorConfiguration : EntityTypeConfiguration<Author>
     {
         public AuthorConfiguration() : this("dbo")

PoweredSoft.DynamicLinq.Dal/Pocos/Uniqe.cs

@@ -0,0 +1,15 @@
+using System;
+using System.Collections.Generic;
+using System.Linq;
+using System.Text;
+using System.Threading.Tasks;
+
+namespace PoweredSoft.DynamicLinq.Dal.Pocos
+{
+    public class Unique
+    {
+        public long Id { get; set; }
+        public Guid RowNumber { get; set; }
+        public Guid? OtherNullableGuid { get; set; }
+    }
+}

PoweredSoft.DynamicLinq.Dal/PoweredSoft.DynamicLinq.Dal.csproj

@@ -50,6 +50,7 @@
   <ItemGroup>
     <Compile Include="BlogContext.cs" />
     <Compile Include="Configurations\Configurations.cs" />
+    <Compile Include="Pocos\Uniqe.cs" />
     <Compile Include="Pocos\Website.cs" />
     <Compile Include="Pocos\CommentLike.cs" />
     <Compile Include="Pocos\Post.cs" />

PoweredSoft.DynamicLinq.Test/ConstantTests.cs

@@ -42,6 +42,14 @@ namespace PoweredSoft.DynamicLinq.Test
             Assert.IsTrue(Posts.AsQueryable().Query(t => t.Equal("Id", 1, QueryConvertStrategy.LeaveAsIs)).Any());
         }
 
+        [TestMethod]
+        public void TestGuid()
+        {
+            var randomGuidStr = Guid.NewGuid().ToString();
+            TestData.Uniques.AsQueryable().Query(t => t.Equal("RowNumber", randomGuidStr));
+            TestData.Uniques.AsQueryable().Query(t => t.Equal("OtherNullableGuid", randomGuidStr));
+        }
+
         [TestMethod]
         public void SpecifyType()
         {

PoweredSoft.DynamicLinq.Test/PoweredSoft.DynamicLinq.Test.csproj

@@ -54,6 +54,9 @@
     <Reference Include="Microsoft.VisualStudio.TestPlatform.TestFramework.Extensions, Version=14.0.0.0, Culture=neutral, PublicKeyToken=b03f5f7f11d50a3a, processorArchitecture=MSIL">
       <HintPath>..\packages\MSTest.TestFramework.1.2.0\lib\net45\Microsoft.VisualStudio.TestPlatform.TestFramework.Extensions.dll</HintPath>
     </Reference>
+    <Reference Include="PoweredSoft.Types, Version=1.0.0.0, Culture=neutral, processorArchitecture=MSIL">
+      <HintPath>..\packages\PoweredSoft.Types.1.0.0\lib\netstandard2.0\PoweredSoft.Types.dll</HintPath>
+    </Reference>
     <Reference Include="System" />
     <Reference Include="System.ComponentModel.DataAnnotations" />
     <Reference Include="System.Core" />

PoweredSoft.DynamicLinq.Test/TestData.cs

@@ -34,6 +34,12 @@ namespace PoweredSoft.DynamicLinq.Test
 
     internal static class TestData
     {
+        static readonly internal List<Unique> Uniques = new List<Unique>
+        {
+            new Unique { Id = 1, RowNumber = Guid.NewGuid(), OtherNullableGuid = null } ,
+            new Unique { Id = 2, RowNumber = Guid.NewGuid(), OtherNullableGuid = Guid.NewGuid() }
+        };
+
         static readonly internal List<MockPersonObject> Persons = new List<MockPersonObject>
         {
             new MockPersonObject { FirstName = "David", LastName = "Lebee", Age = 28 },

PoweredSoft.DynamicLinq.Test/packages.config

@@ -4,4 +4,5 @@
   <package id="Faker.Data" version="1.0.7" targetFramework="net461" />
   <package id="MSTest.TestAdapter" version="1.2.0" targetFramework="net461" />
   <package id="MSTest.TestFramework" version="1.2.0" targetFramework="net461" />
+  <package id="PoweredSoft.Types" version="1.0.0" targetFramework="net462" />
 </packages>

PoweredSoft.DynamicLinq.sln

@@ -13,6 +13,11 @@ Project("{9A19103F-16F7-4668-BE54-9A1E7A4F7556}") = "PoweredSoft.DynamicLinq.Ent
 EndProject
 Project("{FAE04EC0-301F-11D3-BF4B-00C04F79EFBC}") = "PoweredSoft.DynamicLinq.ConsoleApp", "PoweredSoft.DynamicLinq.ConsoleApp\PoweredSoft.DynamicLinq.ConsoleApp.csproj", "{A166BD89-7BF3-475B-871F-294B8A420D9E}"
 EndProject
+Project("{2150E333-8FDC-42A3-9474-1A3956D46DE8}") = "Solution Items", "Solution Items", "{77B4027B-ECB0-4ED1-8646-025AC4146CE2}"
+	ProjectSection(SolutionItems) = preProject
+		README.md = README.md
+	EndProjectSection
+EndProject
 Global
 	GlobalSection(SolutionConfigurationPlatforms) = preSolution
 		Debug|Any CPU = Debug|Any CPU

PoweredSoft.DynamicLinq/Helpers/QueryableHelpers.cs

@@ -327,17 +327,8 @@ namespace PoweredSoft.DynamicLinq.Helpers
             if (value == null)
                 return Expression.Constant(null);
 
-            // the types.
+            var convertedValue = PoweredSoft.Types.Converter.To(value, member.Type);
-            var valueType = value.GetType();
+            return Expression.Constant(convertedValue, member.Type);
-            var memberType = member.Type;
-
-            // if match.
-            if (valueType == memberType)
-                return Expression.Constant(value);
-
-            // attempt a conversion.
-            object convertedValue = TypeHelpers.ConvertFrom(memberType, value);
-            return Expression.Constant(convertedValue, memberType);
         }
 
         public static ConstantExpression ResolveConstant(Expression member, object value, QueryConvertStrategy convertStrategy)
@@ -474,7 +465,7 @@ namespace PoweredSoft.DynamicLinq.Helpers
             foreach (var o in enumerableValue)
             {
                 if (convertStrategy == QueryConvertStrategy.ConvertConstantToComparedPropertyOrField)
-                    list.Add(TypeHelpers.ConvertFrom(memberExpression.Type, o));
+                    list.Add(PoweredSoft.Types.Converter.To(o, memberExpression.Type));
                 else
                     list.Add(o);
             }

PoweredSoft.DynamicLinq/Helpers/TypeHelpers.cs

@@ -24,26 +24,7 @@ namespace PoweredSoft.DynamicLinq.Helpers
         }
 
 
-        public static object ConvertFrom(Type type, object source)
+     
-        {
-            object ret = null;
-
-            // safe if null.
-            if (source == null)
-                return ret;
-
-            // not nullable type.
-            var notNullableType = Nullable.GetUnderlyingType(type);
-            if (notNullableType == null)
-            {
-                ret = Convert.ChangeType(source, type);
-                return ret;
-            }
-
-            // the ret.
-            ret = Convert.ChangeType(source, notNullableType);
-            return ret;
-        }
 
         /*
         /// <summary>

PoweredSoft.DynamicLinq/PoweredSoft.DynamicLinq.csproj

@@ -2,7 +2,7 @@
 
   <PropertyGroup>
     <TargetFramework>netstandard2.0</TargetFramework>
-    <GeneratePackageOnBuild>true</GeneratePackageOnBuild>
+    <GeneratePackageOnBuild>false</GeneratePackageOnBuild>
     <Company>Powered Softwares Inc.</Company>
     <Authors>David Lebée</Authors>
     <Copyright></Copyright>
@@ -22,6 +22,7 @@
   </ItemGroup>
 
   <ItemGroup>
+    <PackageReference Include="PoweredSoft.Types" Version="1.0.0" />
     <PackageReference Include="System.Reflection.Emit" Version="4.3.0" />
   </ItemGroup>