Only Form Fields on the First Page are Saved in Generated PDF

[yangtuooc]

Hello everyone,
I'm encountering an issue while using the pdf-lib library to create form fields on a multi-page PDF. Although the code appears to be correct, only the form fields on the first page are present in the generated PDF file. I'm seeking assistance to resolve this problem.
Here's my code:

import { FormFieldType } from "@/types";
import { PDFDocument, rgb, StandardFonts } from "pdf-lib";

export async function handleSaveAndExport(
  pdfFile: File | null,
  formFields: FormFieldType[]
) {
  if (!pdfFile) return;

  const pdfBytes = await pdfFile.arrayBuffer();
  const pdfDoc = await PDFDocument.load(pdfBytes);
  const form = pdfDoc.getForm();
  const pages = pdfDoc.getPages();

  console.log(pages); // Output shows correct number of pages

  const helveticaFont = await pdfDoc.embedFont(StandardFonts.Helvetica);

  formFields.forEach((field) => {
    const page = pages[field.page - 1];
    const { height } = page.getSize();

    console.log(`Processing field ${field.key} on page ${field.page}`); // This log shows fields being added to different pages

    const textField = form.createTextField(field.key);
    textField.addToPage(page, {
      x: field.x,
      y: height - field.y - field.height, // Adjusting y coordinate as PDF coordinate system starts from bottom
      width: field.width,
      height: field.height,
      borderWidth: 0,
      backgroundColor: rgb(1, 1, 1),
    });

    textField.setFontSize(12);
    textField.setText(field.key);
    textField.enableReadOnly();
    textField.updateAppearances(helveticaFont);
  });

  const pdfBytesWithForm = await pdfDoc.save();
  // ... code to save the file ...
}

Problem Description:

1. Console output shows the correct number of pages in the PDF document.
2. Logs indicate that fields are correctly added to different pages.
3. However, in the generated PDF file, only the first page contains form fields.

I've already tried the following:

1. Opening the generated file with different PDF viewers (including Adobe Acrobat Reader).
2. Checking the size of the generated PDF file to confirm it's larger than the original.
3. Printing field information for each page before and after saving to confirm fields are correctly added.

I suspect the issue might be in the PDF saving or rendering process, but I'm not sure about the exact cause.

Can anyone help me identify the problem? Or do you have any suggestions for further debugging this issue?

Thank you very much for your help!