@crawlee/utils/internals/robots.js

A set of shared utilities that can be used by crawlers

"use strict";
Object.defineProperty(exports, "__esModule", { value: true });
exports.RobotsFile = void 0;
const tslib_1 = require("tslib");
const robots_parser_1 = tslib_1.__importDefault(require("robots-parser"));
const gotScraping_1 = require("./gotScraping");
const sitemap_1 = require("./sitemap");
let HTTPError;
/**
 * Loads and queries information from a [robots.txt file](https://en.wikipedia.org/wiki/Robots.txt).
 *
 * **Example usage:**
 * ```javascript
 * // Load the robots.txt file
 * const robots = await RobotsFile.find('https://crawlee.dev/docs/introduction/first-crawler');
 *
 * // Check if a URL should be crawled according to robots.txt
 * const url = 'https://crawlee.dev/api/puppeteer-crawler/class/PuppeteerCrawler';
 * if (robots.isAllowed(url)) {
 *   await crawler.addRequests([url]);
 * }
 *
 * // Enqueue all links in the sitemap(s)
 * await crawler.addRequests(await robots.parseUrlsFromSitemaps());
 * ```
 */
class RobotsFile {
    constructor(robots, proxyUrl) {
        Object.defineProperty(this, "robots", {
            enumerable: true,
            configurable: true,
            writable: true,
            value: robots
        });
        Object.defineProperty(this, "proxyUrl", {
            enumerable: true,
            configurable: true,
            writable: true,
            value: proxyUrl
        });
    }
    /**
     * Determine the location of a robots.txt file for a URL and fetch it.
     * @param url the URL to fetch robots.txt for
     * @param [proxyUrl] a proxy to be used for fetching the robots.txt file
     */
    static async find(url, proxyUrl) {
        const robotsFileUrl = new URL(url);
        robotsFileUrl.pathname = '/robots.txt';
        robotsFileUrl.search = '';
        return RobotsFile.load(robotsFileUrl.toString(), proxyUrl);
    }
    /**
     * Allows providing the URL and robots.txt content explicitly instead of loading it from the target site.
     * @param url the URL for robots.txt file
     * @param content contents of robots.txt
     * @param [proxyUrl] a proxy to be used for fetching the robots.txt file
     */
    static from(url, content, proxyUrl) {
        return new RobotsFile((0, robots_parser_1.default)(url, content), proxyUrl);
    }
    static async load(url, proxyUrl) {
        if (!HTTPError) {
            HTTPError = (await import('got-scraping')).HTTPError;
        }
        try {
            const response = await (0, gotScraping_1.gotScraping)({
                url,
                proxyUrl,
                method: 'GET',
                responseType: 'text',
            });
            return new RobotsFile((0, robots_parser_1.default)(url.toString(), response.body), proxyUrl);
        }
        catch (e) {
            if (e instanceof HTTPError && e.response.statusCode === 404) {
                return new RobotsFile({
                    isAllowed() {
                        return true;
                    },
                    getSitemaps() {
                        return [];
                    },
                }, proxyUrl);
            }
            throw e;
        }
    }
    /**
     * Check if a URL should be crawled by robots.
     * @param url the URL to check against the rules in robots.txt
     * @param [userAgent] relevant user agent, default to `*`
     */
    isAllowed(url, userAgent = '*') {
        return this.robots.isAllowed(url, userAgent) ?? true; // `undefined` means that there is no explicit rule for the requested URL - assume it's allowed
    }
    /**
     * Get URLs of sitemaps referenced in the robots file.
     */
    getSitemaps() {
        return this.robots.getSitemaps();
    }
    /**
     * Parse all the sitemaps referenced in the robots file.
     */
    async parseSitemaps() {
        return sitemap_1.Sitemap.load(this.robots.getSitemaps(), this.proxyUrl);
    }
    /**
     * Get all URLs from all the sitemaps referenced in the robots file. A shorthand for `(await robots.parseSitemaps()).urls`.
     */
    async parseUrlsFromSitemaps() {
        return (await this.parseSitemaps()).urls;
    }
}
exports.RobotsFile = RobotsFile;
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