GetHostSetting.cs

using System.Threading.Tasks;
using Waher.Runtime.Settings;
using Waher.Script.Abstraction.Elements;
using Waher.Script.Exceptions;
using Waher.Script.Model;
 
namespace Waher.Script.Persistence.Functions
{
    public class GetHostSetting : FunctionMultiVariate
    {
        public GetHostSetting(ScriptNode Host, ScriptNode Name, ScriptNode DefaultValue, int Start, int Length, Expression Expression)
            : base(new ScriptNode[] { Host, Name, DefaultValue }, argumentTypes3Scalar, Start, Length, Expression)
        {
        }
 
        public override string FunctionName => nameof(GetHostSetting);
 
        public override string[] DefaultArgumentNames => new string[] { "Host", "Name", "DefaultValue" };
 
        public override bool IsAsynchronous => true;
 
        public override IElement Evaluate(IElement[] Arguments, Variables Variables)
        {
            return this.EvaluateAsync(Arguments, Variables).Result;
        }
 
        public override async Task<IElement> EvaluateAsync(IElement[] Arguments, Variables Variables)
        {
            string Host = GetSetting.GetHost(Arguments[0].AssociatedObjectValue, this);
 
            if (string.IsNullOrEmpty(Host))
                throw new ScriptRuntimeException("Host not defined.", this);
 
            string Name = ToString(Arguments[1]);
            object DefaultValue = Arguments[2].AssociatedObjectValue;
            object Result;
            Result = await HostSettings.GetAsync(Host, Name, DefaultValue);
 
            return Expression.Encapsulate(Result);
        }
    }
}