oca-ocb-accounting/odoo-bringout-oca-ocb-account_edi_ubl_cii/doc/PATCH_PYPDF2_PDFWRITER.md

PyPDF2 Compatibility Patch - Account EDI UBL CII (OCB)

Overview

This package benefits from the PyPDF2 compatibility fixes implemented in the oca-ocb-base package. The account_edi_ubl_cii module uses OdooPdfFileWriter classes that are automatically compatible with PyPDF2 3.0.0+ through the main compatibility layer.

Problem

In PyPDF2 3.0.0, several classes and methods were deprecated and removed:

• PdfFileWriter → PdfWriter
• PdfFileReader → PdfReader
• cloneReaderDocumentRoot() → clone_reader_document_root()
• Various other method names changed

Affected Functionality

The account_edi_ubl_cii module uses PyPDF2 for:

• UBL (Universal Business Language) invoice PDF generation
• CII (Cross Industry Invoice) document processing
• Electronic invoice XML embedding in PDFs
• Standards-compliant electronic invoicing

Solution

This package includes direct fixes for PyPDF2 3.x page copying issue:

1. Uses OdooPdfFileWriter from odoo.tools.pdf (oca-ocb-base) for compatibility
2. CRITICAL FIX: Added explicit page copying after cloneReaderDocumentRoot()

In PyPDF2 3.x, cloneReaderDocumentRoot() only copies document structure, not content pages. This was causing 327-byte empty PDFs. The fix includes explicit page copying:

writer.cloneReaderDocumentRoot(reader)
# Copy all pages from the reader to the writer (required for PyPDF2 3.x)
for page_num in range(reader.getNumPages()):
    page = reader.getPage(page_num)
    writer.addPage(page)

Files Using PyPDF2

account_edi_ubl_cii/models/ir_actions_report.py

• Uses OdooPdfFileWriter for standards-compliant PDF generation (automatically compatible)
• FIXED: Added explicit page copying after writer.cloneReaderDocumentRoot(reader)
• Embeds UBL/CII XML in PDF documents

Implementation Details

Direct code changes applied in this package:

1. Dependency: Requires oca-ocb-base with pdfwrite branch for compatibility classes
2. Page copying fix: Added explicit page copying loop in _render_qweb_pdf_prepare_streams()
3. Standards compliance: UBL/CII standards maintained through compatibility layer

Testing

The compatibility has been verified with:

• PyPDF2 3.0.0+ (new API)
• PyPDF2 2.x (old API)
• UBL invoice PDF generation
• CII document processing
• XML embedding in compliance documents

Branch Information

• Branch: pdfwrite
• Based on: Current master branch
• Type: Dependency compatibility (no direct patches)
• Impact: Automatic compatibility through oca-ocb-base dependency

Dependencies

CRITICAL: This package requires:

• oca-ocb-base package on pdfwrite branch
• The main PyPDF2 compatibility layer must be active

Standards Compliance

This patch maintains compliance with:

• UBL 2.1: Universal Business Language standard
• CII D16B: Cross Industry Invoice standard
• EN 16931: European electronic invoicing standard
• PDF/A-3: Long-term archival PDF format

Author

• Developer: Ernad Husremović (hernad@bring.out.ba)
• Company: bring.out.doo Sarajevo
• Date: 2025-09-02

Related Issues

This documentation addresses PyPDF2 compatibility for:

• UBL electronic invoicing
• CII standard compliance
• European electronic invoicing (EN 16931)
• B2B/B2G electronic document exchange

Installation

1. Ensure oca-ocb-base is using the pdfwrite branch
2. Use this package's pdfwrite branch (for documentation compliance)
3. No additional installation steps required

Future Considerations

• Monitor oca-ocb-base compatibility updates
• Test UBL/CII workflows with future PyPDF2 versions
• Ensure continued standards compliance with PDF changes