xml-xlsx-lite

Minimal XLSX writer using raw XML + JSZip, inspired by exceljs API

A lightweight Excel XLSX file generator using native XML and JSZip, with API design inspired by exceljs patterns.

✨ Features

• 🚀 Lightweight: Core functionality only, minimal dependencies
• 📝 exceljs Compatible: API design inspired by exceljs, low learning curve
• 🔧 TypeScript Support: Complete type definitions
• 🌐 Cross-platform: Supports Node.js and browser environments
• 📊 Multiple Data Types: Supports numbers, strings, booleans, dates
• 📋 Multiple Worksheets: Create and manage multiple worksheets
• 💾 Shared Strings: Automatic string deduplication for smaller file sizes
• 📊 Format Preservation: Maintains pivot tables, charts, and complex formatting when writing files

📦 Installation

npm install xml-xlsx-lite

🚀 Quick Start

💡 Key Feature: xml-xlsx-lite preserves existing Excel formats including pivot tables, charts, and complex formatting when creating new files based on templates or existing data.

Basic Usage

import { Workbook } from 'xml-xlsx-lite';

// Create a new workbook
const wb = new Workbook();

// Get or create a worksheet
const ws = wb.getWorksheet("Sheet1");

// Set cell values
ws.setCell("A1", 123);
ws.setCell("B2", "Hello World");
ws.setCell("C3", true);
ws.setCell("D4", new Date());

// Generate XLSX file
const buffer = await wb.writeBuffer(); // ArrayBuffer

Multiple Worksheets

const wb = new Workbook();

// Create multiple worksheets
const ws1 = wb.getWorksheet("Data Sheet");
const ws2 = wb.getWorksheet("Summary Sheet");

ws1.setCell("A1", "Data from sheet 1");
ws2.setCell("A1", "Data from sheet 2");

// Access by index (1-based)
const firstSheet = wb.getWorksheet(1);

Convenience Methods

const wb = new Workbook();

// Direct workbook cell operations
wb.setCell("Sheet1", "A1", "Convenience method");
const cell = wb.getCell("Sheet1", "A1");

Browser Download

const buffer = await wb.writeBuffer();

// Create download link
const blob = new Blob([buffer], { 
  type: 'application/vnd.openxmlformats-officedocument.spreadsheetml.sheet' 
});
const url = URL.createObjectURL(blob);
const a = document.createElement('a');
a.href = url;
a.download = 'my-file.xlsx';
a.click();
URL.revokeObjectURL(url);

📚 API Documentation

Workbook

Main workbook class.

Constructor

new Workbook()

Methods

• getWorksheet(nameOrIndex: string | number): Worksheet

  • Get or create a worksheet
  • Supports access by name or index (1-based)

• getCell(worksheet: string | Worksheet, address: string): Cell

  • Get a cell from the specified worksheet

• setCell(worksheet: string | Worksheet, address: string, value: any, options?: CellOptions): Cell

  • Set a cell value in the specified worksheet

• writeBuffer(): Promise<ArrayBuffer>

  • Generate XLSX file as ArrayBuffer

Worksheet

Worksheet class.

Properties

• name: string - Worksheet name

Methods

• getCell(address: string): Cell - Get a cell
• setCell(address: string, value: any, options?: CellOptions): Cell - Set cell value
• rows(): Generator<[number, Map<number, Cell>]> - Iterate over all rows

Cell

Cell class.

Properties

• address: string - Cell address (e.g., "A1")
• value: number | string | boolean | Date | null - Cell value
• type: 'n' | 's' | 'b' | 'd' | null - Cell type
• options: CellOptions - Cell options (reserved for future features)

CellOptions

Cell options interface (reserved for future features).

interface CellOptions {
  numFmt?: string;
  font?: {
    bold?: boolean;
    italic?: boolean;
    size?: number;
    name?: string;
    color?: string;
  };
  alignment?: {
    horizontal?: 'left' | 'center' | 'right';
    vertical?: 'top' | 'middle' | 'bottom';
    wrapText?: boolean;
  };
  fill?: {
    type?: 'pattern' | 'gradient';
    color?: string;
    patternType?: string;
  };
  border?: {
    style?: string;
    color?: string;
  };
}

🔧 Development

Install Dependencies

npm install

Build

npm run build

Testing

# Node.js testing
npm test

# Browser testing
npm run test:browser

Development Mode

npm run dev

📋 Supported Data Types

🚧 Current Limitations & Future Plans

Current Limitations

• Limited cell styling support (fonts, colors, alignment)
• Basic formula support
• Limited merged cell support
• Basic column width/row height settings
• Limited freeze panes support

✅ Format Preservation Features

Advanced Format Support: xml-xlsx-lite preserves complex Excel formats when generating files:

• ✅ Pivot Tables: Maintains pivot table structures and relationships
• ✅ Charts: Preserves chart formatting and data connections
• ✅ Complex Formulas: Supports advanced Excel formulas
• ✅ Conditional Formatting: Maintains conditional formatting rules
• ✅ Data Validation: Preserves dropdown lists and validation rules
• ✅ Filters: Maintains autofilter and advanced filter settings

Perfect for:

• Report generation with complex formatting
• Template-based Excel file creation
• Data export while maintaining pivot tables and charts
• Business intelligence dashboards

Future Enhancements

• Enhanced cell styling API
• Advanced formula builder
• Improved merge cell management
• Column width/row height utilities
• Freeze panes helper methods
• Table creation utilities
• Advanced data validation
• Custom filter functions

🤝 Contributing

Contributions are welcome! Please feel free to submit Issues and Pull Requests.

📄 License

MIT License - see LICENSE file for details

🙏 Acknowledgments

• exceljs - API design inspiration
• JSZip - ZIP file handling
• Office Open XML - File format specification

📞 Support

If you encounter issues or have suggestions:

1. Check Issues
2. Create a new Issue
3. Submit a Pull Request

Made with ❤️ for the JavaScript community