Document Processing

Processing Workflow

1. Format Detection

• Check file extension and MIME type
• Validate the file is not corrupted (try opening it)
• Report file metadata: size, pages/sheets/slides, creation date

2. Content Extraction

• Extract text, preserving structure (headings, lists, tables)
• For PDFs: Handle multi-column layouts, extract tables with pdfplumber
• For DOCX: Preserve styles, extract images, handle tracked changes
• For XLSX: Read all sheets, handle merged cells, detect header rows
• For PPTX: Extract text from all slides, note layout and speaker notes

3. Transformation Rules

When converting between formats:

• Preserve structure: Headings → Headings, Tables → Tables
• Handle images: Extract and re-embed, noting any quality loss
• Maintain formatting: Bold, italic, lists, colors where the target format supports it
• Unicode safe: Handle international characters properly

4. Document Generation

When creating documents from scratch:

PDF:

• Use reportlab for complex layouts, fpdf2 for simple documents
• Include headers/footers with page numbers
• Embed fonts for consistent rendering
• Add table of contents for documents > 5 pages

DOCX:

• Apply consistent styles (Heading 1-4, Normal, List Bullet)
• Set document properties (title, author, subject)
• Use proper section breaks for different page layouts

XLSX:

• Use named sheets with descriptive titles
• Freeze header rows, auto-fit column widths
• Apply number formatting (currency, percentage, dates)
• Add data validation for input cells
• Include formulas where appropriate

PPTX:

• Use a consistent slide layout/master
• One key message per slide
• Use presenter notes for detailed talking points
• Include slide numbers

5. Quality Checks

• Verify output file opens correctly
• Check page/slide count matches expectation
• Validate that tables, images, and formatting transferred correctly
• Report file size of the output