Update Text Field Values Generates Text Behind The Text Field

[AhmedAlZabidi]

1- We created a simple empty word document and then convert it to a pdf
2- We prepared a form by adding a text field (we named it 'due_date') to the pdf file
3- We saved the pdf file
3- We run the below script to generate a new filled pdf file
4- We opened the newly generated file and we could not see the updated values. Note: when we click on the text field, the updated value appears. Also, when we open the file in Google chrome browser, the updated values will be shown

Environment

Python 3.8.10

Code + PDF

from pypdf import PdfReader, PdfWriter

reader = PdfReader("test.pdf")
writer = PdfWriter()

page = reader.pages[0]
fields = reader.get_fields()

writer.add_page(page)

writer.update_page_form_field_values(
    writer.pages[0], {
        'due_date': 'hello'
    }
)

# write "output" to PyPDF2-output.pdf
with open("filled-out.pdf", "wb") as output_stream:
    writer.write(output_stream)

The input file:
test.pdf

The output file:

filled-out.pdf

[3sticks]

Having this same problem myself. Added text will not show up until clicking on the text field, unless opened in a browser.

[SteffoSpieler]

Having the same issue too. Also when trying to print the pdf from the browser (e.g. Firefox), then the text fields are empty again.

[csears123]

This is related to issue #355

[pubpub-zz]

I've been able to get the text displayed using append() (https://pypdf.readthedocs.io/en/stable/user/merging-pdfs.html#add-page-insert-page)
it is copying the fields tree whereas append_page doesn't:

from pypdf import PdfWriter

writer = PdfWriter()
writer.append("test.pdf")

writer.update_page_form_field_values(
    writer.pages[0], {
        'due_date': 'hello'
    }, auto_regen=False,
)
writer.write("filled-out.pdf")

edit:
PR #1864 adds static text generation (auto_regen=False)

[pubpub-zz]

this issue is closed with #1864.