Even though web scraping is crucial for business success, it requires careful planning and execution to minimize or avoid ethical concerns, technical hiccups, or legal issues.
However, there are so many web scraping tactics, each with unique benefits and hurdles. This can make it hard to select the right web scraping tactics. From this piece, you will learn web scraping with Node-Unblocker, a Node.js proxy server library. This is a comprehensive tutorial to get you up and running as quickly as possible.
Table of Contents
This article about web scraping with Node-Unblocker helps you navigate most of the technical hiccups of web scraping. You can avoid IP bans through controlled request frequency, bypass network filters, and implement robust error-handling tactics to manage timeouts and network issues with Node-Unblocker. This is just the tip of the iceberg. Take a deep dive into this step-by-step guide:
1. Install Node.js and npm
You need Node.js, a runtime environment, to execute JavaScript code outside a web browser and npm (Node Package Manager) to easily install, manage, and share reusable JavaScript libraries or packages. Why install the two? Node-Unblocker runs on Node.js, and npm hosts a rich ecosystem of libraries and modules that extend Node-Unblocker’s capabilities.
You can install Node.js and npm using a Node Version Manager (nvm) or the Node installer. Head to the official Node.js website and follow the instructions to install Node.js and npm on Windows, Linux, or MacOS.
After installing the two, open the terminal or command prompt and run these commands to verify the installation:
npm -v2. Set Up Node-Unblocker
As stated, Node-Unblocker is a proxy server library. It is not a standalone proxy but a toolbox for creating proxies with different functionalities and capabilities.
With Node-Unblocker, you can curate a proxy capable of intercepting, modifying, and rerouting HTTP requests before sending the requests to the target server. The same proxy can also intercept responses from the target server and modify the headers of the responses as configured.
Moreover, you can configure the proxy to rewrite URLs, manage HTTP headers, and handle network errors and invalid responses. Not forgetting, you can extend a Node-Unblocker proxy to work with third party proxies to fit specific requirements.
Due to the varying ways you can set up and configure a proxy, a Node Unblocker starter guide can help you navigate its capabilities. For starters, you should be able to deploy Unblocker locally and globally with the help of tools like Express and Render.
3. Select a Scraper Library
Building a Node.js scraper would consume time and resources. To cut down on time, Node.js offers access to scraping libraries you can use in your web scraping scripts. Here are two popular libraries to choose from:
A. Cheerio
This is a fast and lightweight HTML/XML parsing library. If you’ve worked with jQuery before, setting up Cheerio would be a breeze as its syntax mimics jQuery’s.
Use Cheerio to scrape static web pages. Generally, it is a library built to scrape websites that do not rely on Javascript to render content. Moreover, It has limited support for handling AJAX requests. For your dynamic content scraping, opt for Puppeteer.
B. Puppeteer
Puppeteer is a fully-fledged browser automation library. This means you can set it up to interact with web pages just like you do. It can automate browsing actions, including filling forms, scrolling, and clicking, making it a robust tool to reach the data you need.
Use Puppeteer for complex scraping missions, especially those that require you to scrape dynamic websites. It can handle AJAX requests and listen in on specific events. Moreover, you can generate PDFs, automate user interactions, or even take screenshots with the help of Puppeteer.
4. Route Scraping Requests through Node-Unblocker
At this point, we believe you’ve learned how to set up Node-Unblocker within Express, locally or globally. For this tutorial, we’ll use Cheerio to demonstrate how you can route scraping requests through Node-Unblocker. Here is a simple web scraping script demonstrating this:
const express = require('express');
const Unblocker = require('unblocker');
const cheerio = require('cheerio');
const app = express();
const unblocker = Unblocker({ prefix: '/proxy' });
// Define the /scrape route
app.get('/scrape', async (req, res) => {
try {
const url = req.query.url || ‘https://www.example.com’; // Getting the URL to scrape from the query parameters
const response = await unblocker.request(url); // Using Node-Unblocker to fetch the page
const html = response.text; // Where the HTML content is stored or kept
// Using Cheerio to extract specific data
const $ = Cheerio.load(html); // Load the HTML using Cheerio
const pageTitle = $('title').text(); // Example: Extract the page title
// Sending a response back to the client
res.send(`Scraping successful! Page title: ${pageTitle}`);
} catch (error) {
res.status(500).send('Error scraping the website.');
}
});
// Start the server--- running the server on a specific port to get you the required data.
const port = process.env.PORT || 3000;
app.listen(port, () => {
console.log(`Server running on port ${port}`);
});Before using this script, you must assess a website to ensure it is static. Then, obtain the URL to the page you want to scrape and add it to the ‘https://www.example.com’ section to scrape the page. You can customize the extraction further based on your desires. For instance, you can extract other elements like images, headings, etc.
5. Keep practicing
It would help if you kept exploring the integration of Node-Unblocker with third-party proxies to bypass geo-blocked content. Moreover, there are more Node-Unblocker configurations to try out, such as web scraping limit control. However, Node-Unblocker has its own limitations:
Drawbacks of Web Scraping with Node-Unblocker
Unfortunately, When it comes to Web Scraping with Node-Unblocker, Node-Unblocker cannot bypass websites using the OAuth login feature. OAuth is a security feature that allows a website visitor to use an existing accountant like Facebook or Google to access a new website. Also, if a website communicates using methods like “postMessage,” Node-Unblocker won’t help.
Besides being unable to access OAuth-protected sites, Node-Unblocker is limited when scraping complex websites like Facebook, Google, and Amazon. Such websites have several pages and may not let a TCP connection through. Sometimes, the websites might challenge your scraping script with a CAPTCHA (to show that you are not a robot)
Closing Words
There you have it! A comprehensive guide introducing you to the realm of web scraping with Node-Unblocker and a select Node.js web scraping library. Try out other Node-Unblocker features like custom request routing, content modification, and filtering to enhance your scraping experience. And as you keep developing your skills, remember to scrape websites ethically.