OwnerDocument.cs

using System.Threading.Tasks;
using System.Xml;
using Waher.Script.Abstraction.Elements;
using Waher.Script.Exceptions;
using Waher.Script.Model;
using Waher.Script.Objects;
 
namespace Waher.Script.Xml.Functions
{
    public class OwnerDocument : FunctionOneScalarVariable
    {
        public OwnerDocument(ScriptNode Xml, int Start, int Length, Expression Expression)
            : base(Xml, Start, Length, Expression)
        {
        }
 
        public override string FunctionName => nameof(OwnerDocument);
 
        public override string[] DefaultArgumentNames => new string[] { "XML" };
 
        public override IElement EvaluateScalar(IElement Argument, Variables Variables)
        {
            object Obj = Argument.AssociatedObjectValue;
 
            if (Obj is null)
                return Argument;
            else if (Obj is XmlNode N)
                return new ObjectValue(N.OwnerDocument);
            else
                throw new ScriptRuntimeException("XML node expected.", this);
        }
 
        public override Task<IElement> EvaluateScalarAsync(IElement Argument, Variables Variables)
        {
            return Task.FromResult(this.EvaluateScalar(Argument, Variables));
        }
    }
}