PPTX Generator

When to Use This Skill

Use this skill when:

• Creating presentations programmatically from data or specifications

• Populating branded templates with dynamic content while preserving corporate styling

• Extracting text and structure from existing PPTX files for analysis

• Combining slides from a library of approved templates

• Automating presentation generation workflows

Do NOT use this skill when:

• User wants to open/view presentations (use native PowerPoint or viewer)

• Complex animations or transitions are required (limited support)

• Working with older .ppt format (PPTX only)

Prerequisites

• Deno installed (https://deno.land/)

• Input PPTX files for template-based operations

• JSON specification for scratch generation

Quick Start

Two Modes of Operation

Template Mode: Modify existing branded templates

• Analyze & Replace: Find {{PLACEHOLDERS}} and replace with content

• Slide Library: Select and combine slides from a template library

Scratch Mode: Create presentations from nothing using JSON specifications

Instructions

Mode 1: Template-Based Generation

Step 1a: Analyze the Template

Extract text inventory to understand what can be replaced:

deno run --allow-read scripts/analyze-template.ts corporate-template.pptx > inventory.json

Output (inventory.json):

{ "filename": "corporate-template.pptx", "slideCount": 10, "textElements": [ { "slideNumber": 1, "shapeId": "shape-2", "shapeName": "Title 1", "placeholderType": "ctrTitle", "position": { "x": 1.5, "y": 2.0, "w": 7.0, "h": 1.2 }, "paragraphs": [ { "text": "{{TITLE}}", "fontSize": 44, "bold": true } ] } ] }

Step 1b: Create Replacement Specification

Create replacements.json :

{ "textReplacements": [ { "tag": "{{TITLE}}", "value": "Q4 2024 Results" }, { "tag": "{{SUBTITLE}}", "value": "Financial Overview" }, { "tag": "{{DATE}}", "value": "December 2024" }, { "tag": "{{AUTHOR}}", "value": "Finance Team", "slideNumbers": [1] } ] }

Step 1c: Generate Output

deno run --allow-read --allow-write scripts/generate-from-template.ts
corporate-template.pptx replacements.json output.pptx

Mode 1 (Alternative): Slide Library

Step 2a: Preview Template Slides

Get information about available slides:

deno run --allow-read scripts/generate-thumbnails.ts slide-library.pptx

For visual preview, extract the thumbnail:

deno run --allow-read --allow-write scripts/generate-thumbnails.ts
slide-library.pptx --extract-thumb --output-dir ./previews

Step 2b: Select and Combine Slides

Create selections.json :

{ "slideSelections": [ { "slideNumber": 1 }, { "slideNumber": 5 }, { "slideNumber": 12 }, { "slideNumber": 3 } ], "textReplacements": [ { "tag": "{{TITLE}}", "value": "Custom Presentation" } ] }

Step 2c: Generate Combined Presentation

deno run --allow-read --allow-write scripts/generate-from-template.ts
slide-library.pptx selections.json custom-deck.pptx

Mode 2: From-Scratch Generation

Step 3a: Create Specification

Create spec.json :

{ "title": "Product Launch 2025", "author": "Marketing Team", "slides": [ { "background": { "color": "003366" }, "elements": [ { "type": "text", "x": 1, "y": 2.5, "w": 8, "h": 1.5, "options": { "text": "Product Launch 2025", "fontSize": 44, "bold": true, "color": "FFFFFF", "align": "center" } }, { "type": "text", "x": 1, "y": 4, "w": 8, "h": 0.5, "options": { "text": "Revolutionizing the Industry", "fontSize": 24, "color": "CCCCCC", "align": "center" } } ] }, { "elements": [ { "type": "text", "x": 0.5, "y": 0.5, "w": 9, "h": 0.7, "options": { "text": "Key Features", "fontSize": 32, "bold": true, "color": "003366" } }, { "type": "table", "x": 0.5, "y": 1.5, "w": 9, "h": 3, "options": { "rows": [ ["Feature", "Description", "Benefit"], ["Speed", "2x faster processing", "Save time"], ["Quality", "HD output", "Better results"], ["Integration", "Works with existing tools", "Easy adoption"] ], "border": { "pt": 1, "color": "CCCCCC" } } } ] } ] }

Step 3b: Generate Presentation

deno run --allow-read --allow-write scripts/generate-scratch.ts spec.json output.pptx

Examples

Example 1: Corporate Quarterly Report

Scenario: Generate quarterly report from branded template.

Steps:

1. Analyze template for replaceable content

deno run --allow-read scripts/analyze-template.ts quarterly-template.pptx --pretty

2. Create replacements.json with Q4 data

3. Generate report

deno run --allow-read --allow-write scripts/generate-from-template.ts
quarterly-template.pptx replacements.json Q4-2024-Report.pptx

Example 2: Custom Pitch Deck from Slide Library

Scenario: Combine approved slides for a specific client pitch.

Steps:

1. View available slides

deno run --allow-read scripts/generate-thumbnails.ts pitch-library.pptx

2. Create selections.json picking slides 1, 3, 7, 12, 15

3. Generate custom deck

deno run --allow-read --allow-write scripts/generate-from-template.ts
pitch-library.pptx selections.json acme-pitch.pptx

Example 3: Data-Driven Presentation

Scenario: Generate presentation from JSON data (e.g., API response).

Steps:

1. Transform your data into spec.json format

2. Generate presentation

deno run --allow-read --allow-write scripts/generate-scratch.ts data-spec.json report.pptx

Script Reference

Script Purpose Permissions

analyze-template.ts

Extract text inventory from PPTX --allow-read

generate-thumbnails.ts

Get slide info and extract previews --allow-read --allow-write

generate-from-template.ts

Modify templates (replace/combine) --allow-read --allow-write

generate-scratch.ts

Create PPTX from JSON specification --allow-read --allow-write

Element Types (Scratch Mode)

Type Description Key Options

text

Text box text , fontSize , bold , color , align

image

Image from file or base64 path , data , sizing

table

Data table rows , colW , border , fill

shape

Geometric shapes type , fill , line , text

chart

Charts and graphs type , data , title , showLegend

Common Issues and Solutions

Issue: Text not being replaced

Symptoms: Output PPTX still contains {{PLACEHOLDER}} tags.

Solution:

• Run analyze-template.ts to verify exact tag text

• Tags may be split across XML runs - ensure your template has tags in single text runs

• Check slideNumbers filter in replacements

Issue: Slide order incorrect

Symptoms: Slides appear in wrong order after combining.

Solution:

• Slides are added in the order specified in slideSelections

• Verify slide numbers match original template (1-indexed)

Issue: Images not appearing

Symptoms: Image elements are blank in output.

Solution:

• Use absolute paths or paths relative to spec.json location

• Verify image file exists and is readable

• Check supported formats: PNG, JPEG, GIF

OOXML Placeholder Inheritance (Advanced)

Understanding how PowerPoint's OOXML format handles placeholders is crucial for template development.

The Inheritance Chain

PowerPoint uses a hierarchical inheritance model:

Theme → Slide Master → Slide Layout → Slide

• Theme: Defines colors, fonts, effects

• Slide Master: Defines default placeholder positions and formatting (including bullets)

• Slide Layout: Overrides master settings for specific layout types (e.g., Title Slide, Content)

• Slide: Contains actual content, inherits formatting from layout

Key Principles

Text Content Does NOT Inherit: Slides must contain their own text content. The {{placeholder}} text in a layout does NOT automatically appear on slides using that layout.

Text Formatting CAN Inherit: When a slide shape has an empty <a:lstStyle/> , it inherits formatting (color, size, bullets) from the layout's <a:lstStyle> .

Placeholder Linking: Slides link to layouts via <p:ph type="..." idx="..."/> . The type (e.g., "title", "body", "ctrTitle") and idx must match.

Bullet Suppression: To prevent bullets on a placeholder that would normally inherit them from the master's bodyStyle, add <a:buNone/> in the layout's lstStyle.

Defining Inheritable Formatting

In layout placeholders, define colors in <a:lstStyle> (inheritable), not in <a:rPr> (run-specific):

<!-- Layout: Color in lstStyle (GOOD - inheritable) --> <p:txBody> <a:lstStyle> <a:lvl1pPr algn="ctr"> <a:buNone/> <!-- Suppress bullets --> <a:defRPr sz="4400" b="1"> <a:solidFill><a:srgbClr val="FFFFFF"/></a:solidFill> </a:defRPr> </a:lvl1pPr> </a:lstStyle> <a:p> <a:r><a:rPr lang="en-US"/><a:t>{{placeholder}}</a:t></a:r> </a:p> </p:txBody>

Slide Shape Structure

For slides to properly inherit from layouts:

<!-- Slide: Empty lstStyle to inherit from layout --> <p:sp> <p:nvSpPr> <p:cNvPr id="2" name="title 2"/> <p:cNvSpPr><a:spLocks noGrp="1"/></p:cNvSpPr> <p:nvPr> <p:ph type="ctrTitle"/> <!-- Links to layout placeholder --> </p:nvPr> </p:nvSpPr> <p:spPr/> <!-- Empty = inherit position from layout --> <p:txBody> <a:bodyPr/> <a:lstStyle/> <!-- Empty = inherit formatting from layout --> <a:p> <a:r> <a:rPr lang="en-US"/> <!-- Empty = inherit character formatting --> <a:t>{{placeholder}}</a:t> <!-- Content must be here --> </a:r> </a:p> </p:txBody> </p:sp>

Common Issues

Issue Cause Solution

Text shows as black instead of white Color defined in <a:rPr> not <a:lstStyle>

Move color to layout's <a:defRPr> in <a:lstStyle>

Unwanted bullets appearing Master's bodyStyle has bullets, layout doesn't override Add <a:buNone/> to layout's <a:lvl1pPr>

Placeholder text not appearing Text only in layout, not in slide Include text content in slide's <p:txBody>

Formatting not applying Slide has explicit formatting Use empty <a:lstStyle/> and <a:rPr lang="en-US"/>

Reference: Placeholder Types

Type Usage

ctrTitle

Centered title (title slides)

title

Standard title

subTitle

Subtitle

body

Content area (use idx for multiple)

pic

Picture placeholder

dt

Date/time

ftr

Footer

sldNum

Slide number

Limitations

• No slide rendering: Cannot render slides to images directly (use LibreOffice for this)

• Limited animation support: Basic animations only in scratch mode

• No master slide editing: Template mode preserves but doesn't modify masters

• PPTX only: Does not support legacy .ppt format

• Text run splitting: Complex formatting in templates may split tags across XML elements

Related Skills

• pdf-generator: For creating PDF documents instead of presentations

• docx-generator: For creating Word documents

• xlsx-generator: For creating Excel spreadsheets