Building a Web Scraper with JavaScript: A Complete Guide

Data is the primary fuel that ensures the smooth operations of online businesses.

Whether it is a small-scale or well-established enterprise, everyone needs to collect information from the internet. It helps them understand the buying behavior and needs and demands of customers.

But given how vast the internet is, no one can gather accurate information manually. Plus, the process is time-consuming. Well, this is where web scraping comes to the rescue. It is the process of gathering information from the internet using web scraping apps.

Unlike the manual process, web scraper apps make everything automated. So, from downloading structured data to analysis, everything is done automatically. As a result, businesses get accurate data that they use to create a marketing strategy. For this reason, the web scraper development industry is booming like never before.

If you want to build a web scraping app for your digital business, choosing the right tool is of utmost importance. When you read through numerous articles on the internet, you will access a plethora of knowledge on PHP and Python. But in this post, we will enlighten you on how to build a web scraping app with JavaScript.

• Why JavaScript?

As we all know, JavaScript is one of the oldest and widely accepted programming languages on the internet. It is easy to learn while helping developers include complex features in the website with ease. In simple words, JavaScript builds feature-rich, user-friendly, and highly responsive websites.

Do you know Node.Js has made it possible for developers to use JavaScript for web scraper apps? Thanks to its numerous functionalities and features!

So, people hire JavaScript programmers for to get efficient web scraping apps. Let us explore how to create your first web scraping app with JavaScript.

Before we dive into the process of building a web scraper using JavaScript and Node.Js, it is essential to know the prerequisites.

• Prerequisites for building a web scraper using JavaScript

• Chrome or any other browser
  • VSCode
  • Node.js and nvm installed
  • Axios
  • Cheerio
  • Puppeteer

• An ultimate guide to building a web scraper app with JavaScript (Node.Js)

If you have Chrome, VSCode, Node.js, and nvm installed, the next step is creating a new folder. To do so, you need to open a new terminal window, go to the recently created folder, and run npm init-y.

You have to run npm install Axios in the newly created folder. After this, run npm install Cheerio. Also, to ensure you have installed Node.js and nvm properly, head to your terminal and write node-v and nvm-v for verification.

1. Selecting the website

Firstly, you have to choose a website you want to scrape data using Chrome. If you wish to scrape the data efficiently, it is crucial to understand the structure of your selected website.

• Code inspection

Once you access the website, the next step is what every online user would do. For example, you can scroll through the posts on the main page, share the post, leave a comment, and like or dislike. Besides, you can sort the posts by day, week, or month.

Do you want to get a better idea of the data? If yes, then leverage Chrome Dev Tools. They will help you understand the website’s Document Object Model. All you need to do is right-click on the particular page and choose “Inspect” from the options. To access the interactive HTML structure of your selected website, go to the “Elements” tab. Depending on your needs and requirements, you can edit, collapse, expand, or delete elements.

• Writing the code

It is the right time to create a new file called index.js. For this, you have to write the following:

const axios = require(“axios”);

const cheerio = require(“cheerio”);

const fetchTitles = async () => {

try {

const response = await        axios.get(‘https://old.reddit.com/r/movies/‘);

const html = response.data;

const $ = cheerio.load(html);

const titles = [];

$(‘div > p.title > a’).each((_idx, el) => {

const title = $(el).text()

 titles.push(title)

 });

 return titles;

} catch (error) {

 throw error;

}

};

fetchTitles().then((titles) => console.log(titles));

• Running the code

Now that you have finished writing the code, it’s time to run it. For this, you have to type node index.js in the terminal and press enter. Please do not forget to check an array with the titles.

• Storing the collected data

You can store the collected data in a new database, CSV file, or an old array. Of course, the choice depends on your needs and preferences. For example, if you decide to store the scraped data in a CSV file, here is what you should do.

You must have written a code for the index.js file previously. Just change the last line of that code with:

fetchTitles().then((titles) => {

var csv = titles.join(“%0A”);

var a = document.createElement(‘a’);

a.href = ‘data:attachment/csv,’ + csv;

a.target = ‘_blank’;

a.download = titles.csv’;

document.body.appendChild(a);

a.click();

});

Takeaway

JavaScript and Node.js have made web scraping easier than ever. It helps developers to build and perform web scraping. They can use the collected data to create a marketing strategy and integrate it into a use case. Please remember, this guide is most suitable for single-page web applications and simple websites. If you are looking for web scrapping for complicated websites, make sure you tell your needs and goals when you hire mobile app developers in India.

If you are searching for a company that offers web scraper development services, get in touch with SoftProdigy. We are acclaimed as the best mobile app development company in India because of our top-notch quality.