SetVariable.cs

using System;
using System.Collections.Generic;
using System.IO;
using System.Threading.Tasks;
using System.Xml;
using TAG.Simulator.ObjectModel.Values;
using Waher.Content.Xml;
using Waher.Script;
 
namespace TAG.Simulator.ObjectModel.Events
{
    public class SetVariable : EventPreparation, IValueRecipient
    {
        private IValue value = null;
        private string name;
 
        public SetVariable(ISimulationNode Parent, Model Model)
            : base(Parent, Model)
        {
        }
 
        public override string LocalName => nameof(SetVariable);
 
        public string Name => this.name;
 
        public override ISimulationNode Create(ISimulationNode Parent, Model Model)
        {
            return new SetVariable(Parent, Model);
        }
 
        public override Task FromXml(XmlElement Definition)
        {
            this.name = XML.Attribute(Definition, "name");
 
            return base.FromXml(Definition);
        }
 
        public void Register(IValue Value)
        {
            if (this.value is null)
                this.value = Value;
            else
                throw new Exception("SetVariable node already has a value defined.");
        }
 
        public override async Task Prepare(Variables Variables, List<KeyValuePair<string, object>> Tags)
        {
            Variables[this.name] = this.value is null ? null : await this.value.EvaluateAsync(Variables);
        }
 
        public override void Release(Variables Variables)
        {
            Variables.Remove(this.name);
        }
 
        public override void ExportPlantUml(StreamWriter Output, string Name, int Index)
        {
            string s = Index.ToString();
 
            Output.Write("note \"");
            Output.Write(this.name);
            Output.Write('=');
            this.value?.ExportPlantUml(Output, 0, '\'');
            Output.Write("\" as N");
            Output.Write(this.name);
            Output.WriteLine(s);
 
            Output.Write("UC");
            Output.Write(s);
            Output.Write(" .. N");
            Output.Write(this.name);
            Output.WriteLine(s);
        }
    }
}