NullableProperty.cs

using System;
using System.Reflection;
 
namespace Waher.Networking.Cluster.Serialization.Properties
{
    public class NullableProperty : Property
    {
        private readonly Type nullableType;
        private readonly Type elementType;
        private readonly ConstructorInfo constructor;
        private readonly PropertyInfo valueProperty;
        private readonly IProperty element;
 
        public NullableProperty(Type NullableType, Type ElementType, IProperty Element)
            : base()
        {
            this.nullableType = NullableType;
            this.elementType = ElementType;
            this.element = Element;
            this.constructor = null;
 
            foreach (ConstructorInfo CI in this.nullableType.GetTypeInfo().DeclaredConstructors)
            {
                ParameterInfo[] P = CI.GetParameters();
                if (P.Length == 1 && P[0].ParameterType == this.elementType)
                {
                    this.constructor = CI;
                    break;
                }
            }
 
            this.valueProperty = this.nullableType.GetRuntimeProperty("Value");
        }
 
        public override Type PropertyType => this.nullableType;
 
        public override void Serialize(Serializer Output, object Value)
        {
            if (Value is null)
                Output.WriteBoolean(false);
            else
            {
                Output.WriteBoolean(true);
                this.element.Serialize(Output, this.valueProperty.GetMethod.Invoke(Value, null));
            }
        }
 
        public override object Deserialize(Deserializer Input, Type ExpectedType)
        {
            if (Input.ReadBoolean())
                return this.element.Deserialize(Input, this.elementType);
            else
                return null;
        }
    }
}