Respond.cs

using System;
using System.Collections.Generic;
using System.Xml;
using System.Threading.Tasks;
using TAG.Simulator.ObjectModel;
using TAG.Simulator.ObjectModel.Activities;
using TAG.Simulator.ObjectModel.Values;
using TAG.Simulator.XMPP.Actors;
using Waher.Content.Xml;
using Waher.Script;
using System.IO;
 
namespace TAG.Simulator.XMPP.Activities
{
    public class Respond : ActivityNode, IValueRecipient
    {
        private IValue value;
        private StringAttribute actor;
        private StringAttribute to;
        private StringAttribute requestId;
 
        public Respond(ISimulationNode Parent, Model Model)
            : base(Parent, Model)
        {
        }
 
        public override string LocalName => nameof(Respond);
 
        public override string SchemaResource => XmppActor.XmppSchema;
 
        public override string Namespace => XmppActor.XmppNamespace;
 
        public override ISimulationNode Create(ISimulationNode Parent, Model Model)
        {
            return new Respond(Parent, Model);
        }
 
        public override Task FromXml(XmlElement Definition)
        {
            this.actor = new StringAttribute(XML.Attribute(Definition, "actor"));
            this.to = new StringAttribute(XML.Attribute(Definition, "to"));
            this.requestId = new StringAttribute(XML.Attribute(Definition, "requestId"));
 
            return base.FromXml(Definition);
        }
 
        public void Register(IValue Value)
        {
            if (this.value is null)
                this.value = Value;
            else
                throw new Exception("Value already registered.");
        }
 
        public override async Task<LinkedListNode<IActivityNode>> Execute(Variables Variables)
        {
            string To = await this.to.GetValueAsync(Variables);
            string RequestId = await this.requestId.GetValueAsync(Variables);
 
            if (!(await this.GetActorObjectAsync(this.actor, Variables) is XmppActivityObject XmppActor))
                throw new Exception("Actor not an XMPP client.");
 
            object Content = this.value is null ? string.Empty : await this.value.EvaluateAsync(Variables) ?? string.Empty;
            string Xml;
 
            if (Content is XmlDocument Doc)
                Xml = Doc.OuterXml;
            else if (Content is XmlElement E)
                Xml = E.OuterXml;
            else if (Content is null)
                Xml = null;
            else
                throw new Exception("Responses must be XML, or empty.");
 
            await XmppActor.Client.SendIqResult(RequestId, To, Xml);
 
            return null;
        }
 
        public override void ExportPlantUml(StreamWriter Output, int Indentation, char QuoteChar)
        {
            base.ExportPlantUml(Output, Indentation, QuoteChar);
 
            Indent(Output, Indentation);
            Output.Write(':');
            Output.Write(this.actor.Value);
            Output.Write(".Respond");
            Output.Write("(");
 
            Indentation++;
 
            SendMessage.AppendArgument(Output, Indentation, "Id", this.requestId.Value, true, QuoteChar);
            SendMessage.AppendArgument(Output, Indentation, "To", this.to.Value, true, QuoteChar);
 
            if (!(this.value is null))
            {
                if (this.value is Xml Xml && !string.IsNullOrEmpty(Xml.RootName))
                    SendMessage.AppendArgument(Output, Indentation, "Content", Xml.RootName, false, QuoteChar);
                else
                    SendMessage.AppendArgument(Output, Indentation, "Content", this.value, QuoteChar);
            }
 
            Output.WriteLine(");");
        }
 
    }
}