DateTimeIsParsedAsUTC (#277)

* CustomDateTimeConverter

* TargetFrameworks

* uap10.0

* Nullable DateTime

Author: StefH

Directory.Build.props

@@ -4,7 +4,7 @@
     </PropertyGroup>
 
     <PropertyGroup>
-        <VersionPrefix>1.0.18</VersionPrefix>
+        <VersionPrefix>1.0.19</VersionPrefix>
     </PropertyGroup>
 
     <Choose>

System.Linq.Dynamic.Core.sln.DotSettings

@@ -0,0 +1,3 @@
+<wpf:ResourceDictionary xml:space="preserve" xmlns:x="http://schemas.microsoft.com/winfx/2006/xaml" xmlns:s="clr-namespace:System;assembly=mscorlib" xmlns:ss="urn:shemas-jetbrains-com:settings-storage-xaml" xmlns:wpf="http://schemas.microsoft.com/winfx/2006/xaml/presentation">
+	<s:String x:Key="/Default/CodeStyle/Naming/CSharpNaming/Abbreviations/=EF/@EntryIndexedValue">EF</s:String>
+	<s:String x:Key="/Default/CodeStyle/Naming/CSharpNaming/Abbreviations/=UTC/@EntryIndexedValue">UTC</s:String></wpf:ResourceDictionary>

src-console/ConsoleAppEF2.1.1_InMemory/Program.cs

@@ -2,6 +2,7 @@
 using Newtonsoft.Json;
 using System;
 using System.Collections.Generic;
+using System.Globalization;
 using System.Linq;
 using System.Linq.Dynamic.Core;
 using System.Linq.Dynamic.Core.CustomTypeProviders;
@@ -74,6 +75,20 @@ private static void StringEscapeTest()
 
         static void Main(string[] args)
         {
+            var d = new[] { DateTime.UtcNow }.AsQueryable();
+
+            //DateTime.TryParse("Fri, 10 May 2019 11:03:17 GMT", CultureInfo.InvariantCulture, DateTimeStyles.None, out var dateTime);
+            //dateTime.ToUniversalTime().Dump();
+
+            var r = d.Where(dd => dd > DateTime.Parse("Fri, 10 May 2019 11:03:17 GMT")).ToArray();
+
+            var r2 = d.Where("it > \"Fri, 10 May 2019 11:03:17 GMT\"").ToArray();
+
+            // DateTime.Now.ToString("R").Dump();
+
+           return;
+
+
             StringEscapeTest();
             //var q = new[] { new NestedDto(), new NestedDto { NestedDto2 = new NestedDto2 { NestedDto3 = new NestedDto3 { Id = 42 } } } }.AsQueryable();
 

src/EntityFramework.DynamicLinq/EntityFramework.DynamicLinq.csproj

@@ -2,7 +2,6 @@
     <PropertyGroup>
         <Description>Dynamic Linq extensions for EntityFramework which adds Async support</Description>
         <AssemblyTitle>EntityFramework.DynamicLinq</AssemblyTitle>
-        <!--<VersionPrefix>1.0.9.1</VersionPrefix>-->
         <Authors>Stef Heyenrath</Authors>
         <TargetFrameworks>net45;net46</TargetFrameworks>
         <DefineConstants>EF</DefineConstants>

src/Microsoft.EntityFrameworkCore.DynamicLinq/Microsoft.EntityFrameworkCore.DynamicLinq.csproj

@@ -2,7 +2,6 @@
     <PropertyGroup>
         <Description>Dynamic Linq extensions for Microsoft.EntityFrameworkCore which adds Async support</Description>
         <AssemblyTitle>Microsoft.EntityFrameworkCore.DynamicLinq</AssemblyTitle>
-        <!--<VersionPrefix>1.0.9.1</VersionPrefix>-->
         <Authors>Stef Heyenrath</Authors>
         <TargetFrameworks>net451;net46;netstandard1.3;netstandard2.0;uap10.0;netcoreapp2.1</TargetFrameworks>
         <DefineConstants>$(DefineConstants);EFCORE</DefineConstants>

src/System.Linq.Dynamic.Core/Compatibility/CustomIntrospectionExtensions.cs

@@ -1,5 +1,6 @@
 using System.Linq;
 
+// ReSharper disable once CheckNamespace
 namespace System.Reflection
 {
     /// <summary>
@@ -36,4 +37,4 @@ public static Type[] GetGenericTypeArguments(this TypeInfo typeInfo)
         }
 #endif
     }
-}
+}

src/System.Linq.Dynamic.Core/Parser/ExpressionParser.cs

@@ -7,6 +7,7 @@
 using System.Linq.Dynamic.Core.Parser.SupportedMethods;
 using System.Linq.Dynamic.Core.Parser.SupportedOperands;
 using System.Linq.Dynamic.Core.Tokenizer;
+using System.Linq.Dynamic.Core.TypeConverters;
 using System.Linq.Dynamic.Core.Validation;
 using System.Linq.Expressions;
 using System.Reflection;
@@ -29,6 +30,7 @@ public class ExpressionParser
         private readonly TextParser _textParser;
         private readonly IExpressionHelper _expressionHelper;
         private readonly ITypeFinder _typeFinder;
+        private readonly ITypeConverterFactory _typeConverterFactory;
         private readonly Dictionary<string, object> _internals;
         private readonly Dictionary<string, object> _symbols;
 
@@ -75,6 +77,7 @@ public ExpressionParser([CanBeNull] ParameterExpression[] parameters, [NotNull]
             _methodFinder = new MethodFinder(_parsingConfig);
             _expressionHelper = new ExpressionHelper(_parsingConfig);
             _typeFinder = new TypeFinder(_parsingConfig, _keywordsHelper);
+            _typeConverterFactory = new TypeConverterFactory(_parsingConfig);
         }
 
         void ProcessParameters(ParameterExpression[] parameters)
@@ -477,13 +480,13 @@ Expression ParseComparisonOperator()
                         }
                     }
                 }
-                else if ((constantExpr = right as ConstantExpression) != null && constantExpr.Value is string && (typeConverter = TypeConverterFactory.GetConverter(left.Type)) != null)
+                else if ((constantExpr = right as ConstantExpression) != null && constantExpr.Value is string stringValueR && (typeConverter = _typeConverterFactory.GetConverter(left.Type)) != null)
                 {
-                    right = Expression.Constant(typeConverter.ConvertFromInvariantString((string)constantExpr.Value), left.Type);
+                    right = Expression.Constant(typeConverter.ConvertFromInvariantString(stringValueR), left.Type);
                 }
-                else if ((constantExpr = left as ConstantExpression) != null && constantExpr.Value is string && (typeConverter = TypeConverterFactory.GetConverter(right.Type)) != null)
+                else if ((constantExpr = left as ConstantExpression) != null && constantExpr.Value is string stringValueL && (typeConverter = _typeConverterFactory.GetConverter(right.Type)) != null)
                 {
-                    left = Expression.Constant(typeConverter.ConvertFromInvariantString((string)constantExpr.Value), right.Type);
+                    left = Expression.Constant(typeConverter.ConvertFromInvariantString(stringValueL), right.Type);
                 }
                 else
                 {
@@ -1526,7 +1529,7 @@ Expression ParseTypeAccess(Type type)
             return ParseMemberAccess(type, null);
         }
 
-        static Expression GenerateConversion(Expression expr, Type type, int errorPos)
+        private Expression GenerateConversion(Expression expr, Type type, int errorPos)
         {
             Type exprType = expr.Type;
             if (exprType == type)
@@ -1557,21 +1560,11 @@ static Expression GenerateConversion(Expression expr, Type type, int errorPos)
             {
                 string text = (string)((ConstantExpression)expr).Value;
 
-                // DateTime is parsed as UTC time.
-                if (type == typeof(DateTime) && DateTime.TryParse(text, CultureInfo.InvariantCulture, DateTimeStyles.None, out var dateTime))
+                var typeConvertor = _typeConverterFactory.GetConverter(type);
+                if (typeConvertor != null)
                 {
-                    return Expression.Constant(dateTime, type);
-                }
-
-                object[] arguments = { text, null };
-#if NETFX_CORE || WINDOWS_APP || DOTNET5_1 || UAP10_0 || NETSTANDARD
-                MethodInfo method = type.GetMethod("TryParse", new[] { typeof(string), type.MakeByRefType() });
-#else
-                MethodInfo method = type.GetMethod("TryParse", BindingFlags.Public | BindingFlags.Static, null, new Type[] { typeof(string), type.MakeByRefType() }, null);
-#endif
-                if (method != null && (bool)method.Invoke(null, arguments))
-                {
-                    return Expression.Constant(arguments[1], type);
+                    var value = typeConvertor.ConvertFromInvariantString(text);
+                    return Expression.Constant(value, type);
                 }
             }
 

src/System.Linq.Dynamic.Core/ParsingConfig.cs

@@ -92,58 +92,81 @@ public IQueryableAnalyzer QueryableAnalyzer
         /// <summary>
         /// Determines if the context keywords (it, parent, and root) are valid and usable inside a Dynamic Linq string expression.  
         /// Does not affect the usability of the equivalent context symbols ($, ^ and ~).
+        /// 
         /// Default value is true.
         /// </summary>
         public bool AreContextKeywordsEnabled { get; set; } = true;
 
         /// <summary>
-        /// Gets or sets a value indicating whether to use dynamic object class for anonymous types. Default value is false.
+        /// Gets or sets a value indicating whether to use dynamic object class for anonymous types.
+        ///
+        /// Default value is false.
         /// </summary>
         public bool UseDynamicObjectClassForAnonymousTypes { get; set; } = false;
 
         /// <summary>
-        /// Gets or sets a value indicating whether the EntityFramework version supports evaluating GroupBy at database level. Default value is false.
+        /// Gets or sets a value indicating whether the EntityFramework version supports evaluating GroupBy at database level.
         /// See https://docs.microsoft.com/en-us/ef/core/what-is-new/ef-core-2.1#linq-groupby-translation
         /// 
         /// Remark: when this setting is set to 'true', make sure to supply this ParsingConfig as first parameter on the extension methods.
+        ///
+        /// Default value is false.
         /// </summary>
         public bool EvaluateGroupByAtDatabase { get; set; } = false;
 
         /// <summary>
-        /// Use Parameterized Names in generated dynamic SQL query. Default set to false.
+        /// Use Parameterized Names in generated dynamic SQL query.
         /// See https://github.com/graeme-hill/gblog/blob/master/source_content/articles/2014.139_entity-framework-dynamic-queries-and-parameterization.mkd
+        ///
+        /// Default value is false.
         /// </summary>
         public bool UseParameterizedNamesInDynamicQuery { get; set; } = false;
 
         /// <summary>
-        /// Allows the New() keyword to evaluate any available Type. Default value is false.
+        /// Allows the New() keyword to evaluate any available Type.
+        ///
+        /// Default value is false.
         /// </summary>
         public bool AllowNewToEvaluateAnyType { get; set; } = false;
 
         /// <summary>
-        /// Renames the (Typed)ParameterExpression empty Name to a the correct supplied name from `it`. Default value is false.
+        /// Renames the (Typed)ParameterExpression empty Name to a the correct supplied name from `it`.
+        ///
+        /// Default value is false.
         /// </summary>
         public bool RenameParameterExpression { get; set; } = false;
 
         /// <summary>
         /// By default when a member is not found in a type and the type has a string based index accessor it will be parsed as an index accessor. Use
         /// this flag to disable this behaviour and have parsing fail when parsing an expression
-        /// where a member access on a non existing member happens. Default value is false.
+        /// where a member access on a non existing member happens.
+        ///
+        /// Default value is false.
         /// </summary>
         public bool DisableMemberAccessToIndexAccessorFallback { get; set; } = false;
 
         /// <summary>
-        /// By default finding types by a simple name is not suported.
+        /// By default finding types by a simple name is not supported.
         /// Use this flag to use the CustomTypeProvider to resolve types by a simple name like "Employee" instead of "MyDatabase.Entities.Employee".
         /// Note that a first matching type is returned and this functionality needs to scan all types from all assemblies, so use with caution.
+        /// 
         /// Default value is false.
         /// </summary>
         public bool ResolveTypesBySimpleName { get; set; } = false;
 
         /// <summary>
-        /// Support enumeration-types from the System namespace in mscorelib. An example could be "StringComparison".
+        /// Support enumeration-types from the System namespace in mscorlib. An example could be "StringComparison".
+        /// 
         /// Default value is true.
         /// </summary>
         public bool SupportEnumerationsFromSystemNamespace { get; set; } = true;
+
+        /// <summary>
+        /// By default DateTime (like 'Fri, 10 May 2019 11:03:17 GMT') is parsed as local time.
+        /// Use this flag to parse all DateTime strings as UTC.
+        ///
+        /// Default value is false.
+        /// </summary>
+        public bool DateTimeIsParsedAsUTC { get; set; } = false;
     }
 }

src/System.Linq.Dynamic.Core/TypeConverters/CustomDateTimeConverter.cs

@@ -0,0 +1,23 @@
+using System.ComponentModel;
+using System.Globalization;
+
+namespace System.Linq.Dynamic.Core.TypeConverters
+{
+    internal class CustomDateTimeConverter : DateTimeOffsetConverter
+    {
+        /// <summary>
+        /// Converts the specified object to a <see cref="DateTime"></see>.
+        /// </summary>
+        /// <param name="context">The date format context.</param>
+        /// <param name="culture">The date culture.</param>
+        /// <param name="value">The object to be converted.</param>
+        /// <returns>A <see cref="Nullable{DateTime}"></see> that represents the specified object.</returns>
+        /// <exception cref="NotSupportedException">The conversion cannot be performed.</exception>
+        public override object ConvertFrom(ITypeDescriptorContext context, CultureInfo culture, object value)
+        {
+            var dateTimeOffset = base.ConvertFrom(context, culture, value) as DateTimeOffset?;
+
+            return dateTimeOffset?.UtcDateTime;
+        }
+    }
+}

src/System.Linq.Dynamic.Core/TypeConverters/ITypeConverterFactory.cs

@@ -0,0 +1,15 @@
+using JetBrains.Annotations;
+using System.ComponentModel;
+
+namespace System.Linq.Dynamic.Core.TypeConverters
+{
+    interface ITypeConverterFactory
+    {
+        /// <summary>
+        /// Returns a type converter for the specified type.
+        /// </summary>
+        /// <param name="type">The System.Type of the target component.</param>
+        /// <returns>A System.ComponentModel.TypeConverter for the specified type.</returns>
+        TypeConverter GetConverter([NotNull] Type type);
+    }
+}

src/System.Linq.Dynamic.Core/TypeConverterFactory.cs src/System.Linq.Dynamic.Core/TypeConverters/TypeConverterFactory.cs

@@ -2,19 +2,29 @@
 using System.ComponentModel;
 using System.Linq.Dynamic.Core.Validation;
 
-namespace System.Linq.Dynamic.Core
+namespace System.Linq.Dynamic.Core.TypeConverters
 {
-    internal static class TypeConverterFactory
+    internal class TypeConverterFactory : ITypeConverterFactory
     {
-        /// <summary>
-        /// Returns a type converter for the specified type.
-        /// </summary>
-        /// <param name="type">The System.Type of the target component.</param>
-        /// <returns>A System.ComponentModel.TypeConverter for the specified type.</returns>
-        public static TypeConverter GetConverter([NotNull] Type type)
+        private readonly ParsingConfig _config;
+
+        public TypeConverterFactory([NotNull] ParsingConfig config)
+        {
+            Check.NotNull(config, nameof(config));
+
+            _config = config;
+        }
+
+        /// <see cref="ITypeConverterFactory.GetConverter"/>
+        public TypeConverter GetConverter(Type type)
         {
             Check.NotNull(type, nameof(type));
 
+            if (_config.DateTimeIsParsedAsUTC && (type == typeof(DateTime) || type == typeof(DateTime?)))
+            {
+                return new CustomDateTimeConverter();
+            }
+
 #if !SILVERLIGHT
             return TypeDescriptor.GetConverter(type);
 #else
@@ -33,4 +43,4 @@ public static TypeConverter GetConverter([NotNull] Type type)
 #endif
         }
     }
-}
+}

test/System.Linq.Dynamic.Core.Tests/QueryableTests.Select.cs

@@ -19,6 +19,7 @@ public partial class QueryableTests
         public class Example
         {
             public DateTime Time { get; set; }
+            public DateTime? TimeNull { get; set; }
             public DayOfWeek? DOWNull { get; set; }
             public DayOfWeek DOW { get; set; }
             public int Sec { get; set; }