TypesXML

TypesXML is a native TypeScript XML library and processing toolkit — there are no bindings to C/C++ libraries or other native layers. It ships first-class DOM and SAX pipelines, validates full DTD grammars, resolves entities through OASIS XML Catalogs, and passes 100% of the W3C XML Conformance Test Suite for DTD-driven documents.

Features

• DOM builder (DOMBuilder) that produces an in-memory tree and preserves lexical information needed by canonicalization.
• Streaming SAX parser with pull-based file, string, and Node.js stream entry points.
• Complete DTD parser/validator with conditional sections and parameter entities.
• Default attribute extraction from any reachable grammar (DTD, RelaxNG, or XML Schema); defaults merge during SAX parsing independent of validation mode.
• OASIS XML Catalog resolver for public/system identifiers and alternate entity sources.
• Passes 100% of the test cases in the official W3C XML Conformance Test Suite for DTD grammars (valid, invalid, not-wf, external entity cases).
• Canonical XML renderer compatible with the W3C XML Test Suite rules.
• Strict character validation for XML 1.0/1.1 and optional DTD-validating mode.
• Pure TypeScript implementation with type definitions included—ideal for bundlers and ESM/CJS projects.
• XML↔JSON conversion APIs with both lightweight and lossless modes for simple payloads or fully faithful round-trips.

SAX Parser

SAXParser drives any ContentHandler implementation. A handler receives structured callbacks during parsing:

interface ContentHandler {
    initialize(): void;
    setCatalog(catalog: Catalog): void;
    startDocument(): void;
    endDocument(): void;
    xmlDeclaration(version: string, encoding: string, standalone: string): void;
    startElement(name: string, atts: XMLAttribute[]): void;
    endElement(name: string): void;
    internalSubset(declaration: string): void;
    characters(text: string): void;
    ignorableWhitespace(text: string): void;
    comment(text: string): void;
    processingInstruction(target: string, data: string): void;
    startCDATA(): void;
    endCDATA(): void;
    startDTD(name: string, publicId: string, systemId: string): void;
    endDTD(): void;
    skippedEntity(name: string): void;
}

The built-in DOMBuilder implements this interface to provide DOM support out of the box.

Installation

npm install typesxml

Usage

import { DOMBuilder, SAXParser } from "typesxml";

const handler = new DOMBuilder();
const parser = new SAXParser();
parser.setContentHandler(handler);

// Parse from a file
parser.parseFile("example.xml");
const document = handler.getDocument();
console.log(document.toString());

// Parse from a string
parser.parseString("<root><child/></root>");

// Parse from a stream
// await parser.parseStream(fs.createReadStream("example.xml"));

To enable XML Catalog resolution or validation, configure the parser before invoking parse* methods:

parser.setCatalog(myCatalog);
parser.setValidating(true); // Turns on DTD validation only.

Documentation & Samples

• Read the step-by-step TypesXML tutorial for guided workflows.
• Use the JSON and XML Conversion Guide to translate between XML documents and JSON objects, with guidance on when to enable the metadata-preserving round-trip mode.
• Explore the runnable examples under samples/ to see the code in action.

W3C XML Test Suite

The repository includes a harness that runs against the official W3C XML Conformance Test Suite for DTD grammars. To execute it locally:

1. Download the latest archive from the W3C XML Test Suite (e.g., xmlts20080827.zip).

2. Extract the archive into ./tests/xmltest so the valid, invalid, and not-wf folders sit under that path.

3. Install dependencies if needed: npm install.

4. Run the suite:

   npm run testDtd

The script compiles the TypeScript sources and executes ts/tests/DTDTestSuite.ts, reporting any conformance failures.