XmlScriptValue.cs

using System;
using System.Collections;
using System.Collections.Generic;
using System.Numerics;
using System.Threading.Tasks;
using System.Xml;
using Waher.Content;
using Waher.Content.Xml;
using Waher.Persistence;
using Waher.Script.Abstraction.Elements;
using Waher.Script.Model;
using Waher.Script.Objects;
using Waher.Script.Objects.VectorSpaces;
using Waher.Script.Operators.Vectors;
 
namespace Waher.Script.Xml.Model
{
    public class XmlScriptValue : XmlScriptNode
    {
        private ScriptNode node;
        private bool isAsync;
 
        public XmlScriptValue(ScriptNode Node, int Start, int Length, Expression Expression)
            : base(Start, Length, Expression)
        {
            this.node = Node;
            this.node?.SetParent(this);
 
            this.isAsync = Node?.IsAsynchronous ?? false;
        }
 
        public override bool IsAsynchronous => this.isAsync;
 
        public override bool ForAllChildNodes(ScriptNodeEventHandler Callback, object State, SearchMethod Order)
        {
            if (Order == SearchMethod.DepthFirst)
            {
                if (!this.node.ForAllChildNodes(Callback, State, Order))
                    return false;
            }
 
            bool b = !Callback(this.node, out ScriptNode NewNode, State);
            if (!(NewNode is null))
            {
                this.node = NewNode;
                this.node.SetParent(this);
 
                this.isAsync = NewNode.IsAsynchronous;
            }
 
            if (b)
                return false;
 
            if (Order != SearchMethod.DepthFirst)
            {
                if (!this.node.ForAllChildNodes(Callback, State, Order))
                    return false;
            }
 
            return true;
        }
 
        internal override void Build(XmlDocument Document, XmlElement Parent, Variables Variables)
        {
            IElement Bak = Variables.TryGetVariable(ParentNamespaceVariableName, out Variable v) ? v.ValueElement : null;
            Variables[ParentNamespaceVariableName] = Parent.NamespaceURI;
 
            try
            {
                IElement Element = this.node.Evaluate(Variables);
                this.AppendChild(Document, Parent, Element.AssociatedObjectValue);
            }
            finally
            {
                if (Bak is null)
                    Variables.Remove(ParentNamespaceVariableName);
                else
                    Variables[ParentNamespaceVariableName] = Bak;
            }
        }
 
        internal const string ParentNamespaceVariableName = " Parent NS ";
 
        internal override async Task BuildAsync(XmlDocument Document, XmlElement Parent, Variables Variables)
        {
            IElement Bak = Variables.TryGetVariable(ParentNamespaceVariableName, out Variable v) ? v.ValueElement : null;
            Variables[ParentNamespaceVariableName] = Parent.NamespaceURI;
 
            try
            {
                IElement Element = await this.node.EvaluateAsync(Variables);
                this.AppendChild(Document, Parent, Element.AssociatedObjectValue);
            }
            finally
            {
                if (Bak is null)
                    Variables.Remove(ParentNamespaceVariableName);
                else
                    Variables[ParentNamespaceVariableName] = Bak;
            }
        }
 
        private void AppendChild(XmlDocument Document, XmlElement Parent, object Value)
        {
            if (Value is null)
                return;
 
            if (Value is string s)
                Parent.AppendChild(Document.CreateTextNode(s));
            else if (Value is bool b)
                Parent.AppendChild(Document.CreateTextNode(CommonTypes.Encode(b)));
            else if (Value is double d)
                Parent.AppendChild(Document.CreateTextNode(CommonTypes.Encode(d)));
            else if (Value is DateTime TP)
                Parent.AppendChild(Document.CreateTextNode(XML.Encode(TP, TP.TimeOfDay == TimeSpan.Zero)));
            else if (Value is CaseInsensitiveString cis)
                Parent.AppendChild(Document.CreateTextNode(cis.Value));
            else if (Value is BigInteger I)
                Parent.AppendChild(Document.CreateTextNode(I.ToString()));
            else if (Value is XmlDocument Doc)
                Parent.AppendChild(Document.ImportNode(Doc.DocumentElement, true));
            else if (Value is XmlElement E)
                Parent.AppendChild(Document.ImportNode(E, true));
            else if (Value is IEnumerable A)
            {
                IEnumerator e = A.GetEnumerator();
 
                while (e.MoveNext())
                    this.AppendChild(Document, Parent, e.Current);
            }
            else
                Parent.AppendChild(Document.CreateTextNode(Expression.ToString(Value)));
        }
 
        public override PatternMatchResult PatternMatch(XmlNode CheckAgainst, Dictionary<string, IElement> AlreadyFound)
        {
            if (CheckAgainst is XmlText ||
                CheckAgainst is XmlWhitespace ||
                CheckAgainst is XmlSignificantWhitespace ||
                CheckAgainst is XmlCDataSection)
            {
                return this.node.PatternMatch(new StringValue(CheckAgainst.InnerText), AlreadyFound);
            }
            else if (CheckAgainst is XmlElement)
                return this.node.PatternMatch(new ObjectValue(CheckAgainst), AlreadyFound);
            else if (CheckAgainst is null)
            {
                if (this.node is ToVector)
                    return this.node.PatternMatch(new ObjectVector(Array.Empty<object>()), AlreadyFound);
                else
                    return this.node.PatternMatch(ObjectValue.Null, AlreadyFound);
            }
            else
                return PatternMatchResult.NoMatch;
        }
 
        public override PatternMatchResult PatternMatch(IElement CheckAgainst, Dictionary<string, IElement> AlreadyFound)
        {
            return this.node.PatternMatch(CheckAgainst, AlreadyFound);
        }
 
        public override bool IsApplicable(XmlNode CheckAgainst)
        {
            return (CheckAgainst is XmlText ||
                CheckAgainst is XmlWhitespace ||
                CheckAgainst is XmlSignificantWhitespace ||
                CheckAgainst is XmlCDataSection ||
                CheckAgainst is XmlElement);
        }
 
        public override bool IsVector
        {
            get => this.node is ToVector;
        }
 
    }
}