XmlTokenizer.cs

using System;
using System.Collections.Generic;
using System.Reflection;
using System.Text;
using System.Threading.Tasks;
using System.Xml;
using Waher.Runtime.Inventory;
 
namespace Waher.Persistence.FullTextSearch.Tokenizers
{
    public class XmlTokenizer : ITokenizer
    {
        public XmlTokenizer()
        {
        }
 
        public Grade Supports(Type Type)
        {
            if (typeInfo.IsAssignableFrom(Type))
                return Grade.Ok;
            else
                return Grade.NotAtAll;
        }
 
        private static readonly TypeInfo typeInfo = typeof(XmlNode).GetTypeInfo();
 
        public Task Tokenize(object Value, TokenizationProcess Process)
        {
            if (Value is XmlNode N)
                Tokenize(N, Process);
 
            return Task.CompletedTask;
        }
 
        public static void Tokenize(XmlNode Xml, TokenizationProcess Process)
        {
            StringBuilder sb = new StringBuilder();
 
            GetText(Xml, sb);
 
            StringTokenizer.Tokenize(sb.ToString(), Process);
        }
 
        private static void GetText(XmlNode N, StringBuilder Text)
        {
            if (N is XmlElement E)
            {
                foreach (XmlAttribute Attr in E.Attributes)
                {
                    Text.Append(' ');
                    Text.Append(Attr.Value);
                }
            }
            else if (N is XmlText T)
            {
                Text.Append(' ');
                Text.Append(T.InnerText);
            }
            else if (N is XmlCDataSection C)
            {
                Text.Append(' ');
                Text.Append(C.InnerText);
            }
 
            if (N.HasChildNodes)
            {
                foreach (XmlNode N2 in N.ChildNodes)
                    GetText(N2, Text);
            }
        }
    }
}