Losing hidden text when saving PDF DocumentModel to byte array

GemBox.Document
1

I’m building an application where I create a PDF document model from an HTML string and then save the PDF document as a byte array. Then at a later point I load the byte array back into a document model, make changes to it and then save it again. The HTML string contains hidden text (added through <span style="display:none">....</span>). When I convert this to a document model initially the text is still present in the Content property and stays hidden through the CharacterFormat.Hidden property in the Run being set to true. However, when we save the document as a byte array and load it back later, all of the hidden text is gone. Is there any way to preserve hidden text when we’re saving this data?

Here’s a simplified version of the relevant code
Loading from HTML string:

var htmlLoadOptions = new HtmlLoadOptions();
using var htmlStream = new MemoryStream(htmlLoadOptions.Encoding.GetBytes(html));

var document = DocumentModel.Load(htmlStream, htmlLoadOptions);

using var pdfStream = new MemoryStream();
document.Save(pdfStream, new PdfSaveOptions
{
    BookmarksCreateOptions = PdfBookmarksCreateOptions.UsingBookmarks,
});
return pdfStream.ToArray();

Loading from saved byte array

using var htmlStream = new MemoryStream(pdfBytes);
var document = DocumentModel.Load(htmlStream);

using var pdfStream = new MemoryStream();
document.Save(pdfStream, new PdfSaveOptions
{
    BookmarksCreateOptions = PdfBookmarksCreateOptions.UsingBookmarks,
});
return pdfStream.ToArray();
2

This is by design. GemBox.Document doesn’t export hidden texts to PDF. If possible, I would suggest that you save to DOCX file format because hidden texts are preserved in that format. Only other option I can think of is to make those Runs invisible by setting their color to White and size to 0.1.