Add Document Authoring Template Population example

This example demonstrates how to populate Document Authoring templates
with dynamic data using a Mustache-like syntax.

Features:
- Simple placeholder replacement ({{variable}})
- Loops for arrays ({{#array}}...{{/array}})
- Conditionals ({{#condition}}, {{^negated}})
- Table row duplication for array data
- Custom delimiters and default values
- TypeScript with full type safety

The library processes templates in three phases: loops, conditionals,
and simple placeholders, all within a Document Authoring transaction
for atomic updates.

🤖 Generated with Claude Code

Co-Authored-By: Claude <noreply@anthropic.com>

Author: mdjekic

README.md

@@ -88,6 +88,7 @@ Server-side PDF processing and manipulation:
 ## AI & Document Generation
 
 - [AI Document Assistant](https://github.com/PSPDFKit/ai-document-assistant-demo) — Natural language PDF interaction with AI
+- [Document Authoring Template Population](./web/document-authoring-template-population/) — TypeScript library for populating templates with data (placeholders, loops, conditionals, table rows)
 - [Document Generator (Vanilla JS)](./web/document-generator-vanillajs/) — Step-by-step PDF generation with Document Authoring SDK
 
 ---

web/document-authoring-template-population/.gitignore

@@ -0,0 +1,5 @@
+node_modules/
+dist/
+.env
+.DS_Store
+*.log

web/document-authoring-template-population/README.md

@@ -0,0 +1,247 @@
+# Document Authoring Template Data Population
+
+A TypeScript library for applying template data to [Nutrient Document Authoring](https://www.nutrient.io/sdk/document-authoring/) documents. Populate DOCX templates with dynamic data using a Mustache-like syntax for placeholders, loops, and conditionals.
+
+## Features
+
+- **📝 Simple Placeholders** - Replace `{{variable}}` with data values
+- **🔄 Loops** - Duplicate content for arrays using `{{#array}}...{{/array}}`
+- **✅ Conditionals** - Show/hide content with `{{#condition}}...{{/condition}}`
+- **❌ Negated Conditionals** - Invert conditions with `{{^condition}}...{{/condition}}`
+- **📊 Table Support** - Automatically duplicate table rows for array data
+- **⚙️ Custom Delimiters** - Configure your own placeholder syntax
+- **🎨 Formatting Preservation** - Maintains text formatting (bold, italic, fonts, etc.)
+- **🔧 TypeScript** - Full type safety and IDE autocomplete
+
+## Prerequisites
+
+- Node.js 18 or later
+- A Nutrient Document Authoring license key (optional - will show watermark without one)
+
+## Getting Started
+
+### Installation
+
+```bash
+npm install
+```
+
+### Running the Demo
+
+```bash
+npm run dev
+```
+
+Then open [http://localhost:3000](http://localhost:3000) in your browser.
+
+## Usage
+
+### Basic Example
+
+```typescript
+import { applyTemplateData } from './src/index.ts';
+
+// Your template data
+const templateData = {
+  config: {
+    delimiter: { start: '{{', end: '}}' },
+    defaultValue: ''
+  },
+  model: {
+    customerName: 'Acme Corporation',
+    invoiceNumber: 'INV-2024-001',
+    total: '$12,420.00',
+    lineItems: [
+      { description: 'Web Development', quantity: '40', amount: '$6,000.00' },
+      { description: 'UI/UX Design', quantity: '20', amount: '$3,500.00' }
+    ]
+  }
+};
+
+// Apply template data to an open document
+await applyTemplateData(docInstance, templateData);
+```
+
+### Template Syntax
+
+#### Simple Placeholders
+
+Replace with a value from your data model:
+
+```
+Invoice Number: {{invoiceNumber}}
+Customer: {{customerName}}
+Total: {{total}}
+```
+
+#### Loops
+
+Duplicate content for each item in an array:
+
+```
+{{#lineItems}}
+- {{description}}: {{amount}}
+{{/lineItems}}
+```
+
+For tables, the loop duplicates rows:
+
+```
+| Description | Quantity | Amount |
+|-------------|----------|--------|
+| {{#lineItems}}{{description}} | {{quantity}} | {{amount}}{{/lineItems}} |
+```
+
+#### Conditionals
+
+Show content only if a condition is true:
+
+```
+{{#showDiscount}}
+*** SPECIAL DISCOUNT APPLIED ***
+Discount: {{discountAmount}}
+{{/showDiscount}}
+```
+
+#### Negated Conditionals
+
+Show content only if a condition is false:
+
+```
+{{^isPaid}}
+*** PAYMENT DUE ***
+Please pay by {{dueDate}}
+{{/isPaid}}
+```
+
+## Project Structure
+
+```
+document-authoring-template-population/
+├── src/
+│   ├── index.ts                     # Main library export
+│   ├── lib/
+│   │   ├── DocumentTemplating.ts    # Core templating engine
+│   │   ├── parser/
+│   │   │   └── TemplateParser.ts    # Placeholder parsing
+│   │   ├── processors/
+│   │   │   ├── PlaceholderReplacer.ts  # {{variable}} replacement
+│   │   │   ├── ConditionalProcessor.ts # Conditional logic
+│   │   │   └── LoopProcessor.ts        # Array loop handling
+│   │   └── utils/
+│   │       ├── DataResolver.ts      # Data access utilities
+│   │       └── ValidatorUtil.ts     # Validation helpers
+│   └── types/
+│       └── index.ts                 # TypeScript type definitions
+├── index.html                       # Demo application
+├── package.json
+├── tsconfig.json
+├── vite.config.js
+└── README.md
+```
+
+## How It Works
+
+The library processes templates in three phases:
+
+1. **Loop Processing** - Duplicates content (including table rows) for array data
+2. **Conditional Processing** - Shows or hides content based on boolean values
+3. **Placeholder Replacement** - Replaces simple `{{variable}}` placeholders with values
+
+All operations happen within a Document Authoring transaction for atomic updates.
+
+### Table Row Duplication
+
+When a loop (`{{#array}}...{{/array}}`) is detected in a table row:
+
+1. The library identifies the template row
+2. Creates new rows for each array item
+3. Replaces placeholders in each row with item data
+4. Preserves text formatting (font, size, bold, etc.)
+5. Removes the template row
+
+**Note:** Cell-level formatting (borders, backgrounds) uses default styling as the Document Authoring API doesn't currently expose methods to copy these properties.
+
+## API Reference
+
+### `applyTemplateData(instance, data, options?)`
+
+Applies template data to a Document Authoring instance.
+
+**Parameters:**
+- `instance` - The Document Authoring document instance
+- `data` - Template data object containing:
+  - `config.delimiter` - Placeholder delimiters (default: `{{ }}`)
+  - `config.defaultValue` - Value for missing data (default: `''`)
+  - `model` - Your data object
+- `options` - Optional configuration (currently unused)
+
+**Returns:** `Promise<void>`
+
+**Example:**
+
+```typescript
+const data = {
+  config: {
+    delimiter: { start: '{{', end: '}}' },
+    defaultValue: 'N/A'
+  },
+  model: {
+    name: 'John Doe',
+    items: [...]
+  }
+};
+
+await applyTemplateData(doc, data);
+```
+
+## Customization
+
+### Custom Delimiters
+
+Use different placeholder syntax:
+
+```typescript
+const data = {
+  config: {
+    delimiter: { start: '[[', end: ']]' }  // Use [[variable]] instead
+  },
+  model: { ... }
+};
+```
+
+### Default Values
+
+Set a fallback for missing data:
+
+```typescript
+const data = {
+  config: {
+    defaultValue: 'N/A'  // Show 'N/A' instead of empty string
+  },
+  model: { ... }
+};
+```
+
+## Known Limitations
+
+- **Table Formatting**: New rows created by loops will have default borders/backgrounds as the API doesn't expose cell formatting properties
+- **Nested Loops**: Not currently supported
+- **Complex Expressions**: Only simple value lookups are supported (no calculations or filters)
+
+## License
+
+This example is licensed under the MIT License.
+
+## Support
+
+For issues with this example:
+- Create an issue in the [awesome-nutrient repository](https://github.com/PSPDFKit/awesome-nutrient/issues)
+
+For Nutrient Document Authoring SDK support:
+- Visit [Nutrient Support](https://www.nutrient.io/support/)
+- Check the [Document Authoring documentation](https://www.nutrient.io/guides/document-authoring/)
+
+## Contributing
+
+Contributions are welcome! Please feel free to submit a Pull Request.