Index PDF files on Azure about c1-cms-foundation HOT 4 OPEN

public class PdfContentSearchExtension : ISearchDocumentBuilderExtension
    {
        public void Populate(SearchDocumentBuilder searchDocumentBuilder, IData data)
        {
            if (!(data is IMediaFile mediaFile))
            {
                return;
            }

            if (searchDocumentBuilder.TextParts.Any() && !String.IsNullOrEmpty(searchDocumentBuilder.Url))
            {
                return;
            }

            var mimeType = MimeTypeInfo.GetCanonical(mediaFile.MimeType);
            if (!IsIndexableMimeType(mimeType))
            {
                return;
            }

            var text = GetText(mediaFile);
            if (String.IsNullOrWhiteSpace(text))
            {
                return;
            }

            searchDocumentBuilder.TextParts.Add(text);
            searchDocumentBuilder.Url = MediaUrls.BuildUrl(mediaFile, UrlKind.Internal);

            Log.LogInformation("PdfContentSearchExtension", $"{mediaFile.FileName} indexed successfully");
        }

        private static string GetText(IMediaFile mediaFile)
        {
            var sb = new StringBuilder();

            using (var pdfDocument = PdfReader.Open(mediaFile.GetReadStream(), PdfDocumentOpenMode.ReadOnly))
            {
                var extractor = new Extractor(pdfDocument);
                foreach (var page in pdfDocument.Pages)
                {
                    extractor.ExtractText(page, sb);

                    sb.AppendLine();
                }
            }

            return sb.ToString();
        }

        private static bool IsIndexableMimeType(string mimeType)
        {
            return mimeType == "application/pdf";
        }
    }

public static void ConfigureServices(IServiceCollection serviceCollection)
        {
            serviceCollection.AddSingleton<ISearchDocumentBuilderExtension>(new PdfContentSearchExtension());

            Log.LogInformation("Searching", "PdfContentSearchExtension registered");
        }