fix carton centect feed

Author: nafberger

Source/FikaAmazonAPI/ConstructFeed/Messages/CartonContentsRequest.cs

@@ -1,4 +1,5 @@
-using System.Collections.Generic;
+using System;
+using System.Collections.Generic;
 using System.Xml.Serialization;
 
 namespace FikaAmazonAPI.ConstructFeed.Messages
@@ -9,7 +10,11 @@ public class CartonContentsRequest
         [XmlElement(ElementName = "ShipmentId")]
         public string ShipmentId { get; set; }
         [XmlElement(ElementName = "NumCartons")]
-        public int NumCartons { get { return Carton.Count; } }
+        public int NumCartons
+        {
+            get { return Carton.Count; }
+            set { /* required for xml serialization */ }
+        }
         [XmlElement(ElementName = "Carton")]
         public List<Carton> Carton { get; set; } = new List<Carton>();
     }
@@ -32,5 +37,18 @@ public class CartonItem
         public int QuantityShipped { get; set; }
         [XmlElement(ElementName = "QuantityInCase")]
         public int QuantityInCase { get; set; }
+
+        [XmlIgnore]
+        public Nullable<DateTime> ExpirationDate { get; set; }
+
+        [XmlElement(ElementName = "ExpirationDate")]
+        public string ExpirationDateFormatted
+        {
+            get { return this.ExpirationDate.Value.ToString("yyyy-MM-dd"); }
+            set { this.ExpirationDate = DateTime.Parse(value); }
+        }
+
+        [XmlIgnore]
+        public bool ExpirationDateSpecified { get { return ExpirationDate != null; } }
     }
 }