In the 2025 version of the Documents packages, "TimeSpan? timeout" were added to a number of interfaces, with the old versions obsoleted, for example: IWorkbookFormatProvider.Import & IWorkbookFormatProvider.Export.

This is a very strange choice, because this limits the flexibility of the interfaces for no reason at all. By only providing the TimeSpan parameter and not a CancellationToken is currently impossible to cancel the operation because e.g. an API request was canceled.

Internally these methods are implemented by first creating a cancellation token using

using CancellationTokenSource cancellationTokenSource = CancelationTokenSourceFactory.CreateTokenSource(timeout);

the token from this CancellationTokenSource is then passed to a protected method. Because this internal method uses a CancellationToken anyway, there is practically 0 development cost to exposing this in the interface, which makes the choice not to do so even more confusing.

The interfaces should expose methods that take a CancellationToken instead of a TimeSpan. This would allow for the same functionality as the TimeSpan parameter, by simply passing a cancellation token with a CancelAfter set with a TimeSpan, and an extension method could be provided for the interface which does exactly that, so users can still call these methods with a TimeSpan parameter if they wish to do so for convenience.

Please, in the next version, make these interfaces methods like this:

Workbook Import(Stream input, CancellationToken cancellationToken = default);
void Export(Workbook workbook, Stream output, CancellationToken cancellationToken = default);

and, for convenience, add extension methods for these like this:

public static class WorkbookFormatProviderExtensions
{
    public static Workbook Import(this IWorkbookFormatProvider workbookFormatProvider, Stream input, TimeSpan? timeout)
    {
        using CancellationTokenSource cancellationTokenSource = CancelationTokenSourceFactory.CreateTokenSource(timeout);
        return workbookFormatProvider.Import(input, cancellationTokenSource.Token);
    }
}

Affected interfaces I've run into so far:

• Telerik.Windows.Documents.Spreadsheet.FormatProviders.IWorkbookFormatProvider
• Telerik.Windows.Documents.Common.FormatProviders.IFormatProvider<T>

There may be more with this same pattern, I haven't checked.

Add support for pivot tables.

Purpose: Long-term archiving of electronic documents with full semantic structure.

• "A" for Archiving

• Level "1a" ensures:

  • Tagged PDF (with proper logical structure and reading order)

  • Unicode text for proper text extraction and searchability

  • Embedded fonts (for consistent rendering)

• Restrictions:

  • No audio/video

  • No encryption

  • No JavaScript

  • No external content (everything must be self-contained)

• Based on: PDF 1.4 (Acrobat 5)

This type of action is currently not supported and a NotSupportedActionException is thrown when accessing such an object.

These exceptions can be handled using the Handling Exceptions mechanism.

The hierarchical document structure is a means to describe the PDF document structure, which is currently not supported. See 10.6.1 Structure Hierarchy on 856 page of the PDF specification for details.
This document structure is an alternative to the standard PDF structure and most non-Adobe software does not support it.

The document might have been created with Adobe software like Adobe LiveCycle Designer. Very often the document contains some fallback text in the standard PDF structure like:
"Please wait... If this message is not eventually replaced by the proper contents of the document, your PDF viewer may not be able to display this type of document."
"The document you are trying to load requires Adobe Reader 8 or higher. You may not have the Adobe Reader installed or your viewing environment may not be properly configured to use Adobe Reader. For information on how to install Adobe Reader and configure your viewing environment please see  http://www.adobe.com/go/pdf_forms_configure."
"For the best experience, open this PDF portfolio in Acrobat X, Reader X, or later."

• Coons patch meshes (type 6) construct a shading from one or more color
  patches, each bounded by four cubic Bézier curves.