PPF-1164: Feature Request: Enhanced flattening options with configurable text selectability

[LorenzDreyer]

Hi,
first of all - thank you for creating such a great package! It's been a game-changer for me and made life with PDFs so much easier.

Feature Request

I'd like to propose enhanced flattening options that give more control over text selectability.

Current Behavior

When using flatten=True, form fields become non-editable but also lose text selectability/copyability.

Proposed Enhancement

Add different flattening modes:

# Current behavior
pdf.fill(data, flatten=True)  # Non-editable, non-selectable

# Proposed new options
pdf.fill(data, flatten="selectable")    # Non-editable but selectable/copyable
pdf.fill(data, flatten="readonly")      # Non-editable and not selectable/copyable (current)

Use Case

When you send a flattened PDF to someone else, they often need to copy information from it (names, addresses, reference numbers) without being able to edit the form, so the data you entered stays intact.
Currently, my experience is that the implemented flattening method makes this impossible since the text becomes non-selectable. I tried it with various workarounds and other packages, but it's not that easy.

If this is already possible, I would love for you to tell me how this is done easily. Otherwise, I think this feature could be of great value for a lot of people.

Version

PyPDFForm=3.5.1
Python=3.13.2
OS=macOS 26.0

Would love to hear your thoughts - thanks!

[chinapandaman]

Hey, thanks for posting. I'm glad you found this project helpful.

As far as your feature request goes, flatten as a word is a bit misleading under the context of PDF specs. It is actually simply called ReadOnly and it is controlled by a bit in a PDF form field's field flag. If you are interested you can read more about this in Table 221 of the PDF standard.

What PyPDFForm does is to simply flip that bit, and the form field becomes readonly. However, different PDF viewing softwares may render such readonly behavior differently. In the case of Chromium based browsers yes these fields become "unselectable". However, using Adobe Acrobat Reader on macOS you can still highlight and select the filled texts despite being readonly. So this part of the functionalities is controlled by the PDF viewing softwares, not PyPDFForm. As much as I would like this rendering behavior to be more consistent across different PDF viewing softwares, I'm not sure if there's much I can do on my end.

[chinapandaman]

Another example would be that if you just manually fill a PDF form text field on Chrome, you will be able to highlight the text, however you cannot copy those text you highlighted. You could only paste other text into the text field. I'm leaning towards this is an issue on Chromium based browsers.