GroupDocs.Metadata for .NET 18.4 Release Notes

Major Features

There are the following features and fixes in this release:

• BitTorrent format support
• Implement unified DublinCore metadata reader for EPUB, DOCX, PDF
• Implement unified approach of getting image cover across all formats (EPUB, MP3, Word, Excel)

All Changes

Public API and Backward Incompatible Changes

Implement BitTorrent format support 

Description

Implement ability to read and write metadata of torrent files.

Public API changes

TorrentFormat class has been added to GroupDocs.Metadata.Formats.Torrent namespace.
TorrentMetadata class has been added to GroupDocs.Metadata.Formats.Torrent namespace.
TorrentFileInfo class has been added to GroupDocs.Metadata.Formats.Torrent namespace.
Torrent item has been added to GroupDocs.Metadata.DocumentType enum.
Torrent item has been added to GroupDocs.Metadata.MetadataType enum.

Usecases

Read metadata of a torrent file.

using (TorrentFormat torrentFormat = new TorrentFormat(@"D:\input.torrent"))
{
    TorrentMetadata info = torrentFormat.TorrentInfo;
    Console.WriteLine(info.Announce);
    Console.WriteLine(info.CreatedBy);
    Console.WriteLine(info.CreationDate);
    Console.WriteLine(info.Comment);
    Console.WriteLine(info.PieceLength);
    Console.WriteLine(info.Pieces.Length);

    foreach (TorrentFileInfo file in info.SharedFiles)
    {
        Console.WriteLine(file.Name);
        Console.WriteLine(file.Length);
    }
}

Set some properties of torrent file metadata.

using (TorrentFormat torrentFormat = new TorrentFormat(@"D:\input.torrent"))
{
    TorrentMetadata info = torrentFormat.TorrentInfo;

    info.Comment = "test comment";
    info.CreatedBy = "test application";
    info.CreationDate = DateTime.Now;

    torrentFormat.Save(@"D:\output.torrent");
}

Implement unified DublinCore metadata reader for EPUB, DOCX, PDF 

Description

Implement ability to read DublinCore metadata from EPUB, DOCX and PDF files in a unified manner.

Public API changes

None.

Usecases

Read DublinCore metadata using MetadataUtility class.

DublinCoreMetadata dublinCoreMetadata = (DublinCoreMetadata)MetadataUtility.ExtractSpecificMetadata(@"D:\input.docx", MetadataType.DublinCore);

Implement unified approach of getting image cover across all formats (EPUB, MP3, Word, Excel) 

Description

Implement ability to read thumbnail (image cover) from EPUB, MP3, Word and Excel files in a unified manner.

Public API changes

Thumbnail item has been added to GroupDocs.Metadata.MetadataType enum.
ThumbnailMetadata class has been added to GroupDocs.Metadata namespace.

Usecases

Read Thumbnail metadata using MetadataUtility class.

ThumbnailMetadata thumbnailMetadata = (ThumbnailMetadata)MetadataUtility.ExtractSpecificMetadata(@"D:\input.docx", MetadataType.Thumbnail);

Console.WriteLine(thumbnailMetadata.MimeType);
Console.WriteLine(thumbnailMetadata.ImageData.Length);

GIF and PNG file’s size increases after removing metadata   

Description

After removing metadata from Gif and PNG file formats, file size increases.

Public API changes

None.

Usecases

In some cases, it is necessary to remove some specific values from XMP metadata package associated with GIF or PNG images. In previous versions of GroupDocs.Metadata this might cause unexpected increasing of the file size. Starting from version 18.4 please use the following code snippet to avoid the issue.

using (GifFormat format = new GifFormat(@"D:\input.gif"))
{
    XmpEditableCollection xmpEditableCollection = format.XmpValues;
    XmpSchemes schemes = xmpEditableCollection.Schemes;

    schemes.DublinCore.Source = null;
    schemes.DublinCore.Subject = null;

    schemes.Pdf.Keywords = null;
    schemes.Pdf.Producer = null;

    schemes.Photoshop.City = null;
    schemes.Photoshop.Country = null;

    schemes.XmpBasic.BaseUrl = null;
    schemes.XmpBasic.Nickname = null;

    format.Save(@"D:\output.gif");
}

Please note that it’s necessary to use null values (not empty strings) to completely remove appropriate XMP fields from the package.

The JpegFormat() method in GroupDocs.Metadata.dll isn’t safe on MTA 

Description

Creating instances of JpegFormat class is now safe when running in multiple threads. Please note that you still can’t process single JPEG file using different instances of JpegFormat at the same time.

Public API changes

None.

Usecases

None.

Move GroupDocsException class to GroupDocs.Shared.Exceptions namespace 

Description

Move GroupDocsException class to GroupDocs.Shared.Exceptions namespace.

Public API changes

GroupDocsException class has been moved from GroupDocs.Metadata.Exceptions to GroupDocs.Shared.Exceptions namespace.

Usecases

None.