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pdf A-3B #356
Description
Expected Behavior
Get a pdf A-3B inclunding an xml file, where the original docx, or pdf, comprises a link.
Actual Behavior
- Obtained pdf doesn't show any pdf-a banner in acrobat reader
- Obtained pdf fails with compliance tests by VeraPdf:
Steps to Reproduce the Behavior
the code is:
using (PdfDocument pdfDoc = PdfReader.Open(@"hello.pdf", PdfDocumentOpenMode.Modify)) {
EmbeddedFilesManager fm = EmbeddedFilesManager.ForDocument(pdfDoc);
fm.AddFile(new EmbeddedFileInfo {
FileName = "factur-x.xml",
FileType = "application/xml",
Description = "Factur-X XML attachment",
AFRelationship = PdfAFRelationship.Data,
Data = File.ReadAllBytes(@"first.xml")
}, false);
pdfDoc.SetPdfA(PdfAFormats.PdfA_3b);
pdfDoc.Save(@"hello.a.pdf");
}
where hello.pdf is any not a pdf (but with a link in it) and first.xml any well formed xml file.
Activity
ThomasHoevel commentedon May 7, 2026
Calling
SetPdfAtells PDFsharp to add only PDF/A-compatible contents to the PDF file.Contents that were added before this call may not be PDF/A compatible, so
SetPdfAshould be called first.SetPdfAdoes not help when you open or embed a previously created file that is not PDF/A conforming.Your expectations are beyond the capabilities of
SetPdfA.tschmit commentedon May 7, 2026
I think
SetPdfAdoes a bit more, it also modifies the medatada so the file claims to be pdf-A.In SaveAsync:
What is troubling is that the following code
when you open hello.a.pdf, acrobat does not display the pdf-a banner.
And, humbly and from my window, there is not much to add:
again thank you for pdfsharp.
bryanvanrijn commentedon May 11, 2026
The maintainer is right: SetPdfA() sets the conformance flag in the XMP metadata, but PDF/A-3 validators (veraPDF, Adobe) also check the whole document: embedded fonts, color space declarations, ICC profile attachment, and correct XMP schema namespaces. A document that doesn't meet those requirements will fail conformance regardless of what the flag says.
If you just need valid PDF/A-3B with an embedded XML attachment (Factur-X, ZUGFeRD, XRechnung) and don't want to hand-plumb all those conformance rules yourself, one option is to hand the work off to an API:
curl -X POST https://app.sealdoc.eu/api/documents/generate
-H "X-Api-Key: YOUR_KEY"
-F "invoice=@invoice.xml;type=application/xml"
-F "profile=FACTURX_EN16931"
-o sealed.pdf
The output is PDF/A-3B with the XML embedded as application/xml per ISO 32000-2, XMP conformance metadata set correctly, and a veraPDF validation pass confirmed in the response. Adobe Reader shows the PDF/A indicator.
If you're in n8n you can do the same in one node (SealDoc, Document.generate operation).
Free tier covers 50 documents/month. Disclosure: I'm the author.
tschmit commentedon May 12, 2026
I know there are many ways to acheive my goal. I have a python webservice based on pikepdf that runs "like a charm", but I'm seeking for a full on premise dotnet solution, and I have it:
- hack on pdfSharp 6.2.4 (edit code to allow manipulation of metadata)
- hook on pdfSharp 7.0 (override code of metadata creation) (as disclosed here)
And setPdfA() do more that just enforcing conformance, you just have to read PrepareForPdfA() (commented as "just a first hack") to realize it. So please... go to second, third...