Update in-file PDF metadata from within Zotero?

bjohas · April 27, 2021

Hello all,

there isn't a plugin to Zotero that can adjust PDF metadata from the Zotero metadata?

E.g. cpdf can do this on the command line, but I was wondering whether there might be a plugin to zotero that can do that.

adamsmith · April 27, 2021

no. Afaik, there is no existing javascript code or library that writes metatags, so wouldn't be trivial to do and the benefits seem fairly minor. (Jabref does this, FWIW, but Apache pdfBox on java also just gives you that functionality)

bjohas · May 13, 2021

Thanks @adamsmith. I agree that the benefits are minor. We've added an xmp export to https://github.com/OpenDevEd/zotero-lib, and will use cpdf to to add metadata.

Thanks!

qqbb · May 13, 2021

@bjohas: Are you planning to use these tools?
https://github.com/coherentgraphics/cpdf-binaries
https://github.com/johnwhitington/cpdf-source

Here's a JavaScript PDF library which should be able to write XMP metadata:
https://github.com/Hopding/pdf-lib
https://github.com/Hopding/pdf-lib/issues?q=XMP
https://github.com/Hopding/pdf-lib/issues/55
https://github.com/Hopding/pdf-lib/issues/352

Zotero's beta version can already export a PDF attachment with embedded annotations ("File" -> "Save As…"). I don't know what tool this feature is using, but it's probably part of https://github.com/zotero/pdf-worker.

Given Zotero's export option, writing XMP metadata seems not far-fetched. It might, e.g., be required for PDF/A conformance:
https://en.wikipedia.org/wiki/PDF/A
https://github.com/Hopding/pdf-lib/issues/230

See also here for a related discussion:
https://forums.zotero.org/discussion/87048/adding-metadata-to-pdf-properties

bjohas · May 14, 2021

@qqbb - that's is very helpful! I'll explore!

(I've used https://github.com/coherentgraphics/cpdf-binaries for quite a while, and find it really helpful. I didn't know the other tools, but will obviously look.)

Dellu · February 8, 2023

Is there any progress on this feature?
It would really be helpful to be able to write metadata to the pdf from within Zotero. I am currently exporting my references to Jabref just todo the embedding.