Skill: yaodongcheng/pptxgenjs-compat (version 1.0.0)

--- name: pptxgenjs-compat description: > This skill should be used when generating PPT files with pptxgenjs (Node.js library). It provides a complete workflow for creating PowerPoint-compatible PPTX files that won't trigger the "PowerPoint found a problem with content" repair dialog. Covers: safe API usage patterns, post-processing fixes for known pptxgenjs defects, and compatibility verification. Trigger when: creating PPT with pptxgenjs, fixing pptxgenjs-generated PPTX files, or whenever "pptxgenjs" or "PPT" generation is mentioned. --- # pptxgenjs Compatibility Skill Generate PowerPoint-compatible PPTX files using pptxgenjs without triggering repair dialogs. ## The Core Problem pptxgenjs has **6 known defects** (GitHub Issue #1449) that cause PowerPoint to show the "problem with content" repair dialog. The defects are baked into the library's XML generation and **cannot be avoided at the JavaScript level**. A mandatory post-processing step is required after every PPTX generation. ## Workflow ### Step 1: Generate PPTX with Safe API Patterns When writing pptxgenjs code, follow these rules to minimize (but not eliminate) compatibility issues: #### Forbidden APIs (will cause cross-version issues) ``` ❌ shadow — generates complex OOXML effect chains unsupported in many PowerPoint versions ❌ transparency — inconsistent behavior across PowerPoint/WPS/LibreOffice versions ❌ String shape names like "oval", "roundedRectangle" — writes invalid prstGeom values ``` #### Safe Alternatives ``` ✅ Use line borders instead of shadow for visual depth ✅ Use pre-mixed colors instead of transparency (calculate blended colors on dark backgrounds) ✅ Pre-render dimmed icon variants (dark PNG) instead of runtime image transparency ✅ Always use enum constants: pres.shapes.OVAL, pres.shapes.ROUNDED_RECTANGLE ``` #### Pre-mixed Color Calculation To replace transparency on a dark background, calculate the blended color: ``` background #1A1A2E + white at 20% opacity → approximately #3A3A4E ``` For dimmed icons, render at design time with a dark color: ```javascript const iconDim = await iconToBase64Png(FaShield, "3A4450", 256); // dark variant ``` ### Step 2: Post-Process with fix_pptx_compatibility.py **This step is MANDATORY.** Even with perfect API usage, pptxgenjs generates invalid XML that must be fixed. Run the bundled script: ```bash python scripts/fix_pptx_compatibility.py <input.pptx> [output.pptx] ``` If output is omitted, the input file is overwritten in place. The script fixes all 6 known defects: 1. **Phantom slideMaster overrides** in `[Content_Types].xml` — the #1 cause of repair dialogs. pptxgenjs registers non-existent slideMaster2~N.xml for every slide 2. **Invalid theme font references** — replaces `+mn-lt`, `+mn-ea`, `+mn-cs`, `+mj-lt`, `+mj-ea`, `+mj-cs` with `Microsoft YaHei` 3. **dirty= attribute** — removes non-standard pptxgenjs attribute 4. **p14:modId elements** — removes non-standard namespace elements 5. **Notes Slides/Masters** — removes broken notes files and their relationship references 6. **Zero-extent shapes and empty elements** — fixes `cx="0" cy="0"`, `<a:t></a:t>`, `<a:ln />` ### Step 3: Verify Open the PPTX in PowerPoint to confirm no repair dialog appears. For automated verification, check: - All Override PartNames in `[Content_Types].xml` point to existing files - No `+mn-lt` style font references remain - No `dirty=` attributes remain - No `p14:` namespace prefixes remain in slide XMLs ## Common Mistakes to Avoid (Lessons from Real Incidents) 1. **Don't assume shadow/transparency fixes are enough** — The real root cause is usually phantom slideMaster overrides in Content_Types.xml, not visual effects 2. **Don't write validation scripts with `max()` fallback to 0 for `-1` values** — This causes false positives in element order checks 3. **Don't use single-line regex for XML that spans multiple lines** — Use `re.DOTALL` flag 4. **Don't skip post-processing** — Even if the PPTX looks fine in your version of PowerPoint, it may break in others 5. **Search for known issues FIRST** — Before diagnosing compatibility problems from scratch, check GitHub Issues for the library ## Reference For the complete list of pptxgenjs defects with examples and fixes, see `references/pptxgenjs-pitfalls.md`.


Security scan verdicts — ClawScan: clean | static analysis: clean | VirusTotal: clean | SkillSpector: clean (LOW)