creating-presentations

name	creating-presentations
description	Creates, edits, and analyzes PowerPoint presentations (.pptx files), including slide design, chart and table insertion, HTML-to-PPTX conversion, and template-based generation. Activates when the user works with .pptx files or requests presentation authoring.

PowerPoint (.pptx) Guide

This guide covers creating, editing, and analyzing PowerPoint presentations. For HTML-to-PPTX conversion, see html2pptx.md. For OOXML technical details, see ooxml.md.

Workflows Overview

Task	Approach	Reference
Read/analyze slides	Markdown conversion or raw XML	This file
Create from HTML	html2pptx library	html2pptx.md
Create from template	Python scripts	This file
Edit existing PPTX	Unpack/modify/repack	ooxml.md

Important: .pptx files are ZIP archives containing XML and resources.

Reading & Analysis

Convert to Markdown

# Using markitdown
markitdown presentation.pptx > slides.md

Access Raw XML

# Unpack
python ooxml/scripts/unpack.py presentation.pptx unpacked/

# View slide content
cat unpacked/ppt/slides/slide1.xml

# View speaker notes
cat unpacked/ppt/notesSlides/notesSlide1.xml

Create Thumbnail Grid

python scripts/thumbnail.py presentation.pptx thumbnails/

Creates a visual grid showing all slides for quick analysis.

Creating New Presentations

Using html2pptx (Recommended)

1. Create HTML slides with proper dimensions
2. Convert using html2pptx library
3. Add charts/data programmatically

See html2pptx.md for complete guide.

Using Template

# 1. Analyze template
python scripts/inventory.py template.pptx > inventory.json

# 2. Create replacements JSON
# Map placeholder text to new content

# 3. Apply replacements
python scripts/replace.py template.pptx replacements.json output.pptx

Design Principles

Required

• State design approach before writing code
• Use web-safe fonts only: Arial, Helvetica, Times New Roman, Georgia, Courier New, Verdana, Tahoma, Trebuchet MS
• Ensure text contrast ratio ≥ 4.5:1 for readability
• Validate output immediately after creation

Recommended

• Content-informed design (colors/style match topic)
• Consistent visual hierarchy across slides
• Maximum 6 bullet points per slide
• Meaningful use of whitespace

Example Color Palettes

Choose palette based on content:

Style	Background	Primary	Secondary	Accent
Corporate	FFFFFF	2C3E50	34495E	3498DB
Creative	F5F5F5	E74C3C	F39C12	9B59B6
Tech	1A1A2E	16213E	0F3460	E94560
Nature	F0F4F0	27AE60	2ECC71	16A085
Elegant	FAF9F5	141413	B0AEA5	D97757

Supporting Scripts

thumbnail.py

Creates thumbnail grids for visual analysis.

python scripts/thumbnail.py input.pptx output_dir/ [--columns 5]

inventory.py

Extracts all text shapes with properties.

python scripts/inventory.py input.pptx > inventory.json

Output includes:

• Slide number and shape ID
• Text content and formatting
• Position (x, y) and dimensions
• Overflow detection

replace.py

Applies text replacements from JSON.

python scripts/replace.py input.pptx replacements.json output.pptx

Replacements format:

{
  "slide_1": {
    "shape_2": "New title text",
    "shape_5": "Updated bullet points"
  }
}

rearrange.py

Duplicates, reorders, or deletes slides.

python scripts/rearrange.py input.pptx operations.json output.pptx

Operations format (0-indexed):

{
  "operations": [
    {"action": "duplicate", "source": 0, "count": 2},
    {"action": "delete", "index": 5},
    {"action": "move", "from": 3, "to": 1}
  ]
}

validate.py

Validates PPTX structure and content.

python ooxml/scripts/validate.py output.pptx

Checks:

• XML well-formedness
• Required files present
• Relationship integrity
• Content overflow

Editing Existing Presentations

Workflow

1. Unpack: python ooxml/scripts/unpack.py input.pptx unpacked/
2. Modify: Edit XML files directly
3. Validate: python ooxml/scripts/validate.py unpacked/
4. Repack: python ooxml/scripts/pack.py unpacked/ output.pptx

Common Modifications

• Text changes: Edit <a:t> elements in slide XML
• Add images: Add to ppt/media/, update relationships
• Reorder slides: Modify presentation.xml <p:sldIdLst>

See ooxml.md for detailed XML patterns.

Dependencies

# Python
pip install markitdown python-pptx Pillow defusedxml

# JavaScript (for html2pptx)
npm install pptxgenjs playwright sharp

# System tools (for thumbnails)
brew install libreoffice poppler  # macOS
apt-get install libreoffice poppler-utils  # Ubuntu

Best Practices

1. Always validate output immediately after creation
2. Use web-safe fonts to ensure cross-platform compatibility
3. Check overflow - text that doesn't fit won't render
4. Batch similar operations for efficiency
5. Keep unused resources out of final file (fonts, media)
6. Test on target platform - PowerPoint vs Keynote vs Google Slides