Estimated read time: 3 minutes
The LibreOffice Technology now has much better support for creating custom PDF exports of documents: options available in the interactive PDF export options dialog are now also possible to set from the command-line, and also when using the document conversion feature of Collabora Online.
Motivation
I was working on a regression that only happens if you export the second and third pages of a document to PDF. While investigating, I needed a quick way to trigger the problematic code-path, and clicking through a dialog is not convenient.
The PDF export in LibreOffice has a lot of options, but those are only available from extension code
(using the UNO API) or from the UI dialog. The idea was to expose much of this to the soffice
--convert-to command as well, and if we’re at it, also to the /cool/convert-to endpoint of
Online.
Results so far
Here are a few examples to show the possibilities:
-
Skip the first page of a Draw document:
soffice --convert-to 'pdf:draw_pdf_Export:{"PageRange":{"type":"string","value":"2-"}}' test.odg-
Add watermark:
soffice --convert-to 'pdf:draw_pdf_Export:{"TiledWatermark":{"type":"string","value":"draft"}}' test.odg-
Encrypt the output:
soffice --convert-to 'pdf:draw_pdf_Export:{"EncryptFile":{"type":"boolean","value":"true"},"DocumentOpenPassword":{"type":"string","value":"secret"}}' test.odg-
We default to PDF 1.6, perhaps you want to write PDF 1.5:
soffice --convert-to 'pdf:draw_pdf_Export:{"SelectPdfVersion":{"type":"long","value":"15"}}' test.odg-
Sign the PDF:
soffice --convert-to 'pdf:draw_pdf_Export:{"SignPDF":{"type":"boolean","value":"true"},"SignCertificateSubjectName":{"type":"string","value":"CN=..."}}' test.odgAnd the best is that the same also works in Online, e.g.:
curl -k -F "data=@3page.odg" -F "format=pdf" -F "options={\"PageRange\":{\"type\":\"string\",\"value\":\"2-\"}}" https://localhost:9980/cool/convert-to > out.pdfHow is this implemented?
If you would like to know a bit more about how this works, continue reading… :-)
-
https://gerrit.libreoffice.org/c/core/+/128643 tdf#141340 PDF export: fix hyperlinks on the wrong page with page num range was the use-case that initially motivated to add the feature.
-
https://gerrit.libreoffice.org/c/core/+/128709 comphelper: move JsonToPropertyValues() from desktop/ was grounding work to use the "convert JSON to a string-any map" functionality we already had in core.git, as part of the LOK API.
-
https://gerrit.libreoffice.org/c/core/+/128849 PDF export: allow setting filter data keys from the cmdline is the actual improvement to the PDF exporter
-
https://gerrit.libreoffice.org/c/core/+/128970 desktop lok, export options: allow passing through a JSON string as-is is a tweak to let the LOK API also use this
-
https://gerrit.libreoffice.org/c/core/+/129387 filter: allow PDF export to sign from the cmdline added the PDF signing as a string option, since referring to a certificate object from the command-line was not possible
-
https://github.com/CollaboraOnline/online/pull/4069 wsd, convert-to: allow specifying filter options as JSON implemented the Online side
Want to start using this?
You can get a snapshot / demo of Collabora Office and try it out yourself right now: try unstable snapshot. Collabora intends to continue supporting and contributing to LibreOffice, the code is merged so we expect all of this work will be available in TDF’s next release too (7.4).
For the Online side, see the CODE page, the feature is present in the current release (2021).