Class SAXParser

packages/parse5-sax-parser/lib/index.ts:42–237

 * ```
 */
export class SAXParser extends Transform implements TokenHandler {
    protected options: SAXParserOptions;
    /** @internal */
    protected parserFeedbackSimulator: ParserFeedbackSimulator;
    private pendingText: Text | null = null;
    private lastChunkWritten = false;
    private stopped = false;
    protected tokenizer: Tokenizer;

    /**
     * @param options Parsing options.
     */
    constructor(options: SAXParserOptions = {}) {
        super({ encoding: 'utf8', decodeStrings: false });

        this.options = {
            sourceCodeLocationInfo: false,
            ...options,
        };

        this.parserFeedbackSimulator = new ParserFeedbackSimulator(this.options, this);
        this.tokenizer = this.parserFeedbackSimulator.tokenizer;

        // NOTE: always pipe the stream to the /dev/null stream to avoid
        // the `highWaterMark` to be hit even if we don't have consumers.
        // (see: https://github.com/inikulin/parse5/issues/97#issuecomment-171940774)
        this.pipe(new DevNullStream());
    }

    //`Transform` implementation
    override _transform(
        chunk: string,
        _encoding: string,
        callback: (error?: Error | null, data?: string) => void,
    ): void {
        if (typeof chunk !== 'string') {
            throw new TypeError('Parser can work only with string streams.');
        }

        callback(null, this._transformChunk(chunk));
    }

    override _final(callback: (error?: Error | null, data?: string) => void): void {
        this.lastChunkWritten = true;
        callback(null, this._transformChunk(''));
    }

    /**
     * Stops parsing. Useful if you want the parser to stop consuming CPU time
     * once you've obtained the desired info from the input stream. Doesn't
     * prevent piping, so that data will flow through the parser as usual.
     *
     * @example
     *
     * ```js
     * const SAXParser = require('parse5-sax-parser');
     * const http = require('http');
     * const fs = require('fs');