Class XmlParser

packages/core/xml/index.ts:468–653

 * A simple non-validating SAX parser based on https://github.com/vflash/easysax version 0.1.14
 */
export class XmlParser {
	//TODO: Add option to configure whether the parser should report ignorable whitespace, i.e. document formatting whitespace.
	private _parser: EasySAXParser;

	private _processNamespaces: boolean;
	private _namespaceStack: Array<any>;

	/**
	 * Creates a new instance of the XmlParser class.
	 * @param onEvent The callback to execute when a parser event occurs. The 'event' parameter contains information about the event.
	 * @param onError The callback to execute when a parser error occurs. The 'error' parameter contains the error.
	 * @param processNamespaces Specifies whether namespaces should be processed.
	 */
	constructor(onEvent: (event: ParserEvent) => void, onError?: (error: Error, position: Position) => void, processNamespaces?: boolean) {
		this._processNamespaces = processNamespaces;
		this._parser = new EasySAXParser();

		const that = this;
		this._parser.on('startNode', function (elem, attr, uq, tagend, str, pos) {
			let attributes = attr();

			if (attributes === true) {
				//HACK: For some reason easysax returns the true literal when an element has no attributes.
				attributes = undefined;
			}

			if (attributes) {
				for (const key in attributes) {
					if (attributes.hasOwnProperty(key)) {
						// Convert entities such as &gt; to >
						attributes[key] = XmlParser._dereferenceEntities(attributes[key]);
					}
				}
			}

			let prefix = undefined;
			let namespace = undefined;
			let name = elem;

			if (that._processNamespaces) {
				const stackEntry = XmlParser._getNamespacesStackEntry(attributes);
				that._namespaceStack.push(stackEntry);

				const resolved = that._resolveNamespace(name);
				prefix = resolved.prefix;
				namespace = resolved.namespace;
				name = resolved.name;
			}

			onEvent(new ParserEvent(ParserEventType.StartElement, pos(), prefix, namespace, name, attributes, undefined));
		});

		this._parser.on('textNode', function (text, uq, pos) {
			const data = uq(XmlParser._dereferenceEntities(text)); // Decode entity references such as &lt; and &gt;
			onEvent(new ParserEvent(ParserEventType.Text, pos(), undefined, undefined, undefined, undefined, data));
		});

		this._parser.on('endNode', function (elem, uq, tagstart, str, pos) {