Pattern field loses pattern after PDF form export

[UserBlub]

Version: 25.2.6.2 (X86_64)
OS: Windows 11 X86_64

I created a form in LibreOffice Writer and placed a pattern field for an IBAN number.
The objective is to auto format the IBAN for better reading and only allow letters resp. numbers at the corresponding places.
In LibreOffice this works fine when i exit the design mode, the pattern is used an recognised. After Export to PDF with settings:
PDF version: PDF/A-3b
Create PDF form: checked (Submit format PDF)
this looses the formated settings in the PDF. Numbers can be written instead of letters and vice versa. Also the mask is not overwritten when something is entered.

What am I doing wrong?

Attached a minimal example:
Test1.odt (10.4 KB)
Test1.pdf (16.3 KB)

[mariosv]

Problems with fillable PDF in LibreOffice Writer?

[mikekaganski]

@UserBlub

What am I doing wrong?

You are considering LibreOffice an interactive PDF authoring tool. It is not. It allows to create a static copy of a document as a PDF; and it can create a PDF with limited-functionality form controls (it may lack features related to built-in PDF capabilities; and it definitely has zero support for anything requiring scripts in PDFs).

Use a proper PDF authoring tool. And of course, you are welcome to file bug reports, so that everything that can be improved, gets a chance.

[UserBlub]

It seems that my objective unfortunately isn’t achievable with LibreOffice at the moment.

Interestingly, other Form Controls like Combo Box, Date Field, and Numerical Field do work correctly in the exported PDF. That’s why I assumed Pattern Fields would behave similarly, especially since the Form Controls help page mentions that pattern fields aren’t supported in HTML export, but doesn’t list any limitations for PDF export.

If this is a known limitation, it might be helpful to clarify it in the help page. And if it’s not yet reported, perhaps someone more familiar with the development process could file a bug or feature request to improve support in future versions.

Also, does anyone know of a free and open-source tool that can create or edit PDF forms with input masks or pattern-based validation? I’m not sure if this forum is the best place to ask about alternative software, but I’d appreciate any suggestions if someone happens to know.

Thanks again for the insights!

[EarnestAl]

Do a search on something like “software input mask in pdf forms”. I suspect you might find only commercial software, or just Acrobat

@UserBlub

perhaps someone more familiar with the development process could file a bug or feature request to improve support in future versions.

https://wiki.documentfoundation.org/QA/BugReport