My Web Crawler

my-web-crawler is a simple, lightweight Node.js package for crawling websites and generating an XML sitemap. It recursively follows internal links, making it a useful tool for SEO analysis, website auditing, or content discovery.

Features

• Recursively crawls internal links starting from a specified URL
• Generates an XML sitemap of all visited pages
• Rate-limiting to avoid overloading the target server
• Uses axios for HTTP requests and cheerio for parsing HTML

Installation

To install the package, run:

npm install my-web-crawler

Usage

1. Import the Web Crawler

After installing the package, you can import it into your project using either CommonJS or ES6 modules.

CommonJS Syntax

const WebCrawler = require('my-web-crawler');

ES6 Modules Syntax

import WebCrawler from 'my-web-crawler';

2. Crawling a Website

You can create a new instance of the WebCrawler class by providing the starting URL. The crawl method recursively crawls the site, and the saveSitemap method generates and saves the sitemap.

Example

const WebCrawler = require('my-web-crawler');

// Specify the starting URL
const startUrl = 'http://codewithdeepak.in';
const crawler = new WebCrawler(startUrl);

// Start crawling and save the sitemap
crawler.crawl(startUrl).then(() => {
  crawler.saveSitemap('sitemap.xml');  // Saves the sitemap to 'sitemap.xml'
}).catch(err => {
  console.error('Error during crawl:', err);
});

3. Rate Limiting

The crawler includes a delay between requests to avoid overwhelming the target website. The delay is set to 50 milliseconds by default, but you can customize it when initializing the WebCrawler.

Example

const crawler = new WebCrawler(startUrl, 100 , limit);  // Delay of 100 ms between requests
  // Set the limit of number of urls to crawl (optional)

API

WebCrawler Class

constructor(startUrl, delayMs = 50, limit = 50)

• startUrl: The URL to start crawling from.
• delayMs: Optional. The delay in milliseconds between requests (default is 50 ms).

async crawl(url)

Starts the crawling process. This method will recursively follow all internal links starting from the given URL.

• url: The URL to crawl.

saveSitemap(filename)

Generates an XML sitemap from the visited URLs and saves it to the specified file.

• filename: The file where the sitemap will be saved (e.g., sitemap.xml).

Example Script

Here’s how you can use the package in a simple script:

// crawler-script.js
const WebCrawler = require('my-web-crawler');

const startUrl = 'http://codewithdeepak.in';
const crawler = new WebCrawler(startUrl);

crawler.crawl(startUrl).then(() => {
  crawler.saveSitemap('sitemap.xml');
}).catch(err => {
  console.error('Error during crawl:', err);
});

To run the script:

node crawler-script.js

Dependencies

• axios: Promise-based HTTP client for the browser and Node.js.
• cheerio: Fast, flexible, and lean implementation of core jQuery designed specifically for the server.

License

This project is licensed under the MIT License - see the LICENSE file for details.

Contributing

Feel free to contribute by submitting issues or pull requests. All contributions are welcome!

Author

Created by CodeWithCraze.

Summary:

This README.md file provides an overview of the package, installation instructions, usage examples, and API details. You can customize it further based on your specific requirements or additional features of the package.