VAST Unwrapper

A TypeScript library for parsing and unwrapping VAST (Video Ad Serving Template) XML documents. This library supports VAST versions 2.0 through 4.2 and provides a robust solution for handling both inline and wrapper VAST ads.

Features

• Supports VAST versions 2.0 to 4.2
• Handles both inline and wrapper VAST ads
• Automatic unwrapping of VAST wrapper chains
• Configurable wrapper depth limit
• Error tracking and reporting
• XML validation
• Macro resolution support
• TypeScript support with comprehensive type definitions

Installation

npm install vast-unwrapper

Usage

import { VASTParser } from 'vast-unwrapper';

// Initialize the parser
const parser = new VASTParser({
    maxWrapperDepth: 5, // Optional, defaults to 6
    proxyUrl: 'https://your-proxy-url.com' // Required for CORS handling
});

// Parse VAST from URL
async function parseVastFromUrl(vastUrl: string) {
    try {
        const ads = await parser.getAndParseVastXml(vastUrl);
        console.log('Parsed ads:', ads);
    } catch (error) {
        console.error('Error parsing VAST:', error);
    }
}

// Parse VAST from XML string
async function parseVastFromString(vastXmlString: string) {
    try {
        const ads = await parser.parseVastXMLFromString(vastXmlString);
        console.log('Parsed ads:', ads);
    } catch (error) {
        console.error('Error parsing VAST:', error);
    }
}

API Reference

VASTParser

Main class for parsing VAST documents.

Constructor

new VASTParser(config: ParserConfig)

• config.maxWrapperDepth (optional): Maximum depth for wrapper resolution (default: 6)
• config.proxyUrl (required): URL for proxy server to handle CORS requests

Methods

• getAndParseVastXml(url: string): Promise<AdObject[]> Fetches and parses a VAST document from the given URL

• parseVastXMLFromString(vastString: string): Promise<AdObject[]> Parses a VAST XML string

• parseVastXML(vastXml: XMLDocument): Promise<AdObject[]> Parses a VAST XML document

Development

Setup

npm install

Build

npm run build

Test

npm test

Lint

npm run lint

Contributing

Contributions are welcome! Please feel free to submit a Pull Request.

License

MIT