Add DateTimeOffset filter support (gustavnavar/Grid.Blazor#249)

GridShared/Filtering/Types/DateTimeOffsetFilterType.cs

@@ -0,0 +1,67 @@
+using System;
+using System.Globalization;
+using System.Linq.Expressions;
+
+namespace GridShared.Filtering.Types
+{
+    /// <summary>
+    ///     Object contains some logic for filtering DateTimeOffset columns
+    /// </summary>
+    public sealed class DateTimeOffsetFilterType : FilterTypeBase
+    {
+        public override Type TargetType
+        {
+            get { return typeof(DateTimeOffset); }
+        }
+
+        public override Expression GetFilterExpression(Expression leftExpr, string value, GridFilterType filterType)
+        {
+            //var dateExpr = Expression.Property(leftExpr, leftExpr.Type, "Date");
+
+            //if (filterType == GridFilterType.Equals)
+            //{
+            //    var dateObj = GetTypedValue(value);
+            //    if (dateObj == null) return null;//not valid
+
+            //    var startDate = Expression.Constant(dateObj);
+            //    var endDate = Expression.Constant(((DateTime)dateObj).AddDays(1));
+
+            //    var left = Expression.GreaterThanOrEqual(leftExpr, startDate);
+            //    var right = Expression.LessThan(leftExpr, endDate);
+
+            //    return Expression.And(left, right);
+            //}
+
+            return base.GetFilterExpression(leftExpr, value, filterType);
+        }
+
+        /// <summary>
+        ///     There are filter types that allowed for DateTime column
+        /// </summary>
+        /// <param name="type"></param>
+        /// <returns></returns>
+        public override GridFilterType GetValidType(GridFilterType type)
+        {
+            switch (type)
+            {
+                case GridFilterType.Equals:
+                case GridFilterType.NotEquals:
+                case GridFilterType.GreaterThan:
+                case GridFilterType.GreaterThanOrEquals:
+                case GridFilterType.LessThan:
+                case GridFilterType.LessThanOrEquals:
+                    return type;
+                default:
+                    return GridFilterType.Equals;
+            }
+        }
+
+        public override object GetTypedValue(string value)
+        {
+            DateTimeOffset date;
+            if (!DateTimeOffset.TryParse(value, CultureInfo.InvariantCulture, DateTimeStyles.None, out date))
+                return null;
+            return date;
+        }
+    }
+}

GridShared/Filtering/Types/FilterTypeResolver.cs

@@ -15,6 +15,7 @@ public FilterTypeResolver()
             _filterCollection.Add(new Int16FilterType());
             _filterCollection.Add(new BooleanFilterType());
             _filterCollection.Add(new DateTimeFilterType());
+            _filterCollection.Add(new DateTimeOffsetFilterType());
             _filterCollection.Add(new DecimalFilterType());
             _filterCollection.Add(new ByteFilterType());
             _filterCollection.Add(new SingleFilterType());