SparqlResultSetHtmlEncoder.cs

using System;
using System.Text;
using System.Threading.Tasks;
using Waher.Content.Html;
using Waher.Content.Markdown.Rendering;
using Waher.Runtime.Inventory;
using Waher.Script.Objects.Matrices;
 
namespace Waher.Content.Semantic
{
    public class SparqlResultSetHtmlEncoder : IContentEncoder
    {
        public SparqlResultSetHtmlEncoder()
        {
        }
 
        public string[] ContentTypes => Array.Empty<string>();
 
        public string[] FileExtensions => Array.Empty<string>();
 
        public bool Encodes(object Object, out Grade Grade, params string[] AcceptedContentTypes)
        {
            if (Object is SparqlResultSet &&
                InternetContent.IsAccepted(HtmlCodec.HtmlContentTypes, AcceptedContentTypes))
            {
                Grade = Grade.Excellent;
                return true;
            }
            else if (Object is ObjectMatrix M && M.HasColumnNames &&
                InternetContent.IsAccepted(HtmlCodec.HtmlContentTypes, AcceptedContentTypes))
            {
                Grade = Grade.Ok;
                return true;
            }
            else if (Object is bool &&
                InternetContent.IsAccepted(HtmlCodec.HtmlContentTypes, AcceptedContentTypes))
            {
                Grade = Grade.Barely;
                return true;
            }
            else
            {
                Grade = Grade.NotAtAll;
                return false;
            }
        }
 
        public async Task<ContentResponse> EncodeAsync(object Object, Encoding Encoding, ICodecProgress Progress, params string[] AcceptedContentTypes)
        {
            string Html;
 
            if (Encoding is null)
                Encoding = Encoding.UTF8;
 
            if (Object is SparqlResultSet Result)
            {
                if (Result.BooleanResult.HasValue)
                    Html = CommonTypes.Encode(Result.BooleanResult.Value);
                else
                {
                    using (HtmlRenderer Renderer = new HtmlRenderer(new HtmlSettings()))
                    {
                        await Renderer.RenderObject(Result.ToMatrix(true), true, new Script.Variables());
                        Html = Renderer.ToString();
                    }
                }
            }
            else if (Object is ObjectMatrix M)
            {
                using (HtmlRenderer Renderer = new HtmlRenderer(new HtmlSettings()))
                {
                    await Renderer.RenderObject(M, true, new Script.Variables());
                    Html = Renderer.ToString();
                }
            }
            else if (Object is bool b)
                Html = CommonTypes.Encode(b);
            else
                return new ContentResponse(new ArgumentException("Unable to encode object.", nameof(Object)));
 
            byte[] Bin = Encoding.GetBytes(Html);
            string ContentType = HtmlCodec.HtmlContentTypes[0] + "; charset=" + Encoding.WebName;
 
            return new ContentResponse(ContentType, Object, Bin);
        }
 
        public bool TryGetContentType(string FileExtension, out string ContentType)
        {
            ContentType = null;
            return false;
        }
 
        public bool TryGetFileExtension(string ContentType, out string FileExtension)
        {
            FileExtension = null;
            return false;
        }
    }
}