XmlScriptProcessingInstruction.cs

using System.Collections.Generic;
using System.Text.RegularExpressions;
using System.Xml;
using Waher.Script.Abstraction.Elements;
using Waher.Script.Model;
 
namespace Waher.Script.Xml.Model
{
    public class XmlScriptProcessingInstruction : XmlScriptLeafNode
    {
        private readonly string text;
 
        public XmlScriptProcessingInstruction(string Text, int Start, int Length, Expression Expression)
            : base(Start, Length, Expression)
        {
            this.text = Text;
        }
 
        internal override void Build(XmlDocument Document, XmlElement Parent, Variables Variables)
        {
            int i = this.text.IndexOf(' ');
 
            if (i < 0)
                Document.CreateProcessingInstruction(this.text, string.Empty);
            else
            {
                Match M = xmlDeclaration.Match(this.text);
 
                if (M.Success && M.Index == 0 && M.Length == this.text.Length)
                {
                    string Version = M.Groups["Version"].Value;
                    string Encoding = M.Groups["Encoding"].Value;
                    string Standalone = M.Groups["Standalone"].Value;
 
                    Document.AppendChild(Document.CreateXmlDeclaration(Version, Encoding, Standalone));
                }
                else
                {
                    string Target = this.text.Substring(0, i);
                    string Data = this.text.Substring(i + 1).Trim();
 
                    Document.AppendChild(Document.CreateProcessingInstruction(Target, Data));
                }
            }
        }
 
        private static readonly Regex xmlDeclaration = new Regex("\\s*xml\\s*(((version=['\"](?'Version'[^'\"]*)['\"])|(encoding=['\"](?'Encoding'[^'\"]*)['\"])|(standalone=['\"](?'Standalone'[^'\"]*)['\"]))\\s*)*", RegexOptions.Compiled | RegexOptions.Singleline | RegexOptions.IgnoreCase);
 
        public override PatternMatchResult PatternMatch(XmlNode CheckAgainst, Dictionary<string, IElement> AlreadyFound)
        {
            int i = this.text.IndexOf(' ');
 
            if (i < 0)
            {
                return CheckAgainst is XmlProcessingInstruction PI && PI.Target == this.text && string.IsNullOrEmpty(PI.Data) ?
                    PatternMatchResult.Match : PatternMatchResult.NoMatch;
            }
            else
            {
                Match M = xmlDeclaration.Match(this.text);
 
                if (M.Success && M.Index == 0 && M.Length == this.text.Length)
                {
                    string Version = M.Groups["Version"].Value;
                    string Encoding = M.Groups["Encoding"].Value;
                    string Standalone = M.Groups["Standalone"].Value;
 
                    return CheckAgainst is XmlDeclaration D && D.Version == Version && D.Encoding == Encoding &&
                        D.Standalone == Standalone ? PatternMatchResult.Match : PatternMatchResult.NoMatch;
                }
                else
                {
                    string Target = this.text.Substring(0, i);
                    string Data = this.text.Substring(i + 1).Trim();
 
                    return CheckAgainst is XmlProcessingInstruction PI && PI.Target == Target && PI.Data == Data ?
                        PatternMatchResult.Match : PatternMatchResult.NoMatch;
                }
            }
        }
 
        public override bool IsApplicable(XmlNode CheckAgainst)
        {
            return (CheckAgainst is XmlProcessingInstruction || CheckAgainst is XmlDeclaration);
        }
 
    }
}