PageMetaDataTokenizer.cs

using System;
using System.Text;
using System.Threading.Tasks;
using Waher.Content.Html;
using Waher.Content.Html.OpenGraph;
using Waher.Persistence.FullTextSearch;
using Waher.Persistence.FullTextSearch.Tokenizers;
using Waher.Runtime.Inventory;
 
namespace Waher.IoTGateway.Tokenizers
{
    public class PageMetaDataTokenizer : ITokenizer
    {
        public PageMetaDataTokenizer()
        {
        }
 
        public Grade Supports(Type Type)
        {
            if (Type == typeof(PageMetaData))
                return Grade.Ok;
            else
                return Grade.NotAtAll;
        }
 
        public async Task Tokenize(object Value, TokenizationProcess Process)
        {
            if (Value is PageMetaData Data)
                await Tokenize(Data, Process);
        }
 
        public static Task Tokenize(PageMetaData Data, TokenizationProcess Process)
        {
            StringBuilder sb = new StringBuilder();
            bool First = true;
 
            Append(sb, ref First, Data.Determiner);
            Append(sb, ref First, Data.Title);
            Append(sb, ref First, Data.Description);
            Append(sb, ref First, Data.SiteName);
            Append(sb, ref First, Data.Locale);
            Append(sb, ref First, Data.LocaleAlternate);
 
            if (!(Data.Images is null))
            {
                foreach (ImageInformation Info in Data.Images)
                    Append(sb, ref First, Info.Description);
            }
 
            StringTokenizer.Tokenize(sb.ToString(), Process);
 
            return Task.CompletedTask;
        }
 
        private static void Append(StringBuilder Text, ref bool First, string[] Value)
        {
            if (!(Value is null))
            {
                foreach (string s in Value)
                    Append(Text, ref First, s);
            }
        }
 
        private static void Append(StringBuilder Text, ref bool First, string Value)
        {
            if (!string.IsNullOrEmpty(Value))
            {
                if (First)
                    First = false;
                else
                    Text.Append(' ');
 
                Text.Append(Value);
            }
        }
    }
}