oca-edi/odoo-bringout-oca-edi-pdf_helper/doc/PATCH_PYPDF2_PDFWRITER.md

PyPDF2 Compatibility Patch - PDF Helper (EDI)

Overview

This package benefits from the PyPDF2 compatibility fixes implemented in the oca-ocb-base package. The pdf_helper module uses OdooPdfFileWriter and OdooPdfFileReader 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
• Various method names changed (e.g., addPage() → add_page())

Affected Functionality

The pdf_helper module uses PyPDF2 indirectly through:

• OdooPdfFileWriter for embedding XML attachments in PDFs
• OdooPdfFileReader for extracting XML files from PDF documents
• XML-to-PDF embedding for EDI workflows
• PDF parsing and attachment processing

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

pdf_helper/utils.py

• Imports PdfReadError with compatibility handling
• Uses OdooPdfFileReader (automatically compatible)

pdf_helper/models/helper.py

• Uses OdooPdfFileWriter and OdooPdfFileReader (automatically compatible)
• FIXED: Added explicit page copying after cloneReaderDocumentRoot() and addAttachment()

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 loops in multiple methods
3. Import handling: Exception imports handle both old and new PyPDF2 locations

Testing

The compatibility has been verified with:

• PyPDF2 3.0.0+ (new API)
• PyPDF2 2.x (old API)
• XML embedding in PDFs
• XML extraction from PDFs
• EDI document processing workflows

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

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:

• EDI XML embedding workflows
• PDF attachment processing
• Electronic document interchange

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 EDI workflows with future PyPDF2 versions
• Consider direct PyPDF2 usage optimization if needed