Add XFA support to AcroForm module

[dsolankii]

Summary

• add addXFA entry point to embed XFA payloads and toggle NeedRendering
• normalize stream/array inputs, emit XFA packets during document build, and keep AcroForm fallbacks intact
• add regression coverage and extend TypeScript typings for the new API

Testing

• npm run build
• npm run test-unit
• npm run test-node
• npm run test-amd
• npm run test-esm
• npm run test-globals
• npm run test-typescript
• npm run test-webworker

Closes #3886

(Friendly note: I’m participating in Hacktoberfest—thanks for tagging or merging!)

[JDziurlaj]

Thank you for working on this! There is one typo that is causing issues, otherwise LGTM! (Looking back at the originating issue, the typo was mine! 😳)

[JDziurlaj]

Should be NeedsRendering (plural). Check and fix throughout PR.

[dsolankii]

Thanks for catching that! I’ve updated the code/tests to use /NeedsRendering and pushed the change.

[HackbrettXXX]

Thanks for this PR. I'm no expert regarding XFA, but the code generally looks good. Could you add a test case that creates/compares a PDF with a reference, so I can check if the created PDF works.

[HackbrettXXX]

I think we should also rename this field to "needsRendering"

[dsolankii]

Thanks for the review! I’ve renamed the internal flag to needsRendering and added a regression test in test/specs/acroform.spec.js (it("addXFA generates expected PDF")) that compares the generated file against the new reference test/reference/xfa-basic.pdf.

You can reproduce it with:

npm run test-unit -- --grep "addXFA generates expected PDF" --reporters mocha

The reference PDF contains /NeedsRendering true in the catalog and the /XFA [(datasets) … (template) …] packets (verified via qpdf --qdf --object-streams=disable test/reference/xfa-basic.pdf -). Happy to adjust anything else!