Rule.cs

using System;
using System.Xml;
using Waher.Persistence.Attributes;
 
namespace Waher.Service.IoTBroker.Provisioning.Rules
{
    [TypeName(TypeNameSerialization.LocalName)]
    public abstract class Rule
    {
        public const string RuleNamespace = "http://waher.se/Schema/Provisioning/Rules.xsd";
 
        private Rule[] childRules = null;
 
        public Rule()
        {
        }
 
        [DefaultValueNull]
        public Rule[] ChildRules
        {
            get => this.childRules;
            set => this.childRules = value;
        }
 
        public virtual bool? Evaluate(Context Context)
        {
            bool? Result;
 
            if (!(this.childRules is null))
            {
                foreach (Rule Rule2 in this.childRules)
                {
                    Result = Rule2.Evaluate(Context);
                    if (Result.HasValue)
                        return Result;
                }
            }
 
            return null;
        }
 
        public void AddChildRule(Rule Rule)
        {
            if (this.childRules is null)
                this.childRules = new Rule[] { Rule };
            else
            {
                int c = this.childRules.Length;
                Array.Resize(ref this.childRules, c + 1);
                this.childRules[c] = Rule;
            }
        }
 
        public abstract void Export(XmlWriter Output);
 
        protected virtual void ExportChildren(XmlWriter Output)
        {
            if (!(this.childRules is null))
            {
                foreach (Rule Rule in this.childRules)
                    Rule.Export(Output);
            }
        }
    }
}