relative date time feature

src/Gridify/Builder/BaseQueryBuilder.cs

@@ -166,18 +166,28 @@ private static object AddIndexerNullCheck(LambdaExpression mapTarget, object que
 
       object? value = valueExpression.ValueToken.Text;
 
+      var underlyingBodyType = Nullable.GetUnderlyingType(body.Type);      
       // execute user custom Convertor
       if (convertor != null)
          value = convertor.Invoke(valueExpression.ValueToken.Text);
 
       // handle the `null` keyword in value
-      if (mapper.Configuration.AllowNullSearch && op.Kind is SyntaxKind.Equal or SyntaxKind.NotEqual && value.ToString() == "null")
+      else if (mapper.Configuration.AllowNullSearch && op.Kind is SyntaxKind.Equal or SyntaxKind.NotEqual && value.ToString() == "null")
          value = null;
-
-      // type fixer
-      // Check if body.Type is a nullable type and get its underlying type issue #134
-      var underlyingBodyType = Nullable.GetUnderlyingType(body.Type);
-      if (value is string strValue && (underlyingBodyType ?? body.Type) != strValue.GetType())
+
+      else if (body.Type == typeof(DateTime) || underlyingBodyType == typeof(DateTime))
+      {
+         var dateTime = ParseRelativeDate(valueExpression.ValueToken.Text);
+         if (dateTime.HasValue)
+         {
+            value = dateTime.Value;
+            if (mapper.Configuration.DefaultDateTimeKind.HasValue)
+            {
+               value = DateTime.SpecifyKind((DateTime)value, mapper.Configuration.DefaultDateTimeKind.Value);
+            }
+         }
+      }
+      else if (value is string strValue && (underlyingBodyType ?? body.Type) != strValue.GetType())
       {
          // handle bool, github issue #71
          if (body.Type == typeof(bool) && strValue is "true" or "false" or "1" or "0")
@@ -199,14 +209,6 @@ private static object AddIndexerNullCheck(LambdaExpression mapTarget, object que
             {
                return BuildAlwaysFalseQuery(parameter);
             }
-
-         if (value is DateTime dateTime)
-         {
-            if (mapper.Configuration.DefaultDateTimeKind.HasValue)
-            {
-               value = DateTime.SpecifyKind(dateTime, mapper.Configuration.DefaultDateTimeKind.Value);
-            }
-         }
       }
 
       // handle case-Insensitive search
@@ -240,4 +242,14 @@ private static LambdaExpression UpdateIndexerKey(LambdaExpression exp, string ke
       var body = new ReplaceExpressionVisitor(exp.Parameters[1], newValue).Visit(exp.Body);
       return Expression.Lambda(body, exp.Parameters);
    }
+
+   private static DateTime? ParseRelativeDate(string input)
+   {
+      var parser = new Chronic.Core.Parser();
+      var result = parser.Parse(input);
+      if (result != null) return result.Start;
+
+      DateTime.TryParse(input, out var dateTime);
+      return dateTime;
+   }
 }

src/Gridify/Gridify.csproj

@@ -49,6 +49,7 @@
    </ItemGroup>
 
    <ItemGroup>
+      <PackageReference Include="Chronic.Core" Version="0.4.0" />
       <PackageReference Include="Microsoft.SourceLink.GitHub" Version="1.1.1" PrivateAssets="All" />
 
    </ItemGroup>

test/Gridify.Tests/GridifyExtensionsShould.cs

@@ -676,6 +676,29 @@ public void ApplyFiltering_UnmappedFields_ShouldSkipWhenIgnored()
       Assert.True(actual.Any());
    }
 
+   [Fact]
+   public void ApplyFiltering_DateTime()
+   {
+      var actual = _fakeRepository.AsQueryable()
+         .ApplyFiltering($"MyDateTime>{DateTime.UtcNow.ToShortDateString()}")
+         .ToList();
+      var expected = _fakeRepository.Where(q => q.MyDateTime > DateTime.UtcNow.Date).ToList();
+
+      Assert.Equal(expected.Count, actual.Count);
+   }
+
+   [Fact]
+   public void ApplyFiltering_DateTime_Relative()
+   {
+      var actual = _fakeRepository.AsQueryable()
+         .ApplyFiltering("MyDateTime>today")
+         .ToList();
+      var expected = _fakeRepository.Where(q => q.MyDateTime > DateTime.UtcNow.Date).ToList();
+
+      Assert.Equal(expected.Count, actual.Count);
+   }
+
+
    #endregion