How Javascript Affects Web Design and Web Scraping
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Blog arrow Science of Web Scraping

How Javascript Affects Web Design and Web Scraping

Gabriel Cioci
Frontend Developer @ WebScrapingAPI
Summary

If you like web design, you probably know a bit about Javascript, but have you asked yourself how it affects web scraping? Here's the rundown

Do you remember the wild west phase of the Internet, when every website designer just did their own things, and pages would be filled with mismatched colors, weird UI choices, and stretched-out images? What a time to be alive.

Moreover, think back to how those websites looked if you accessed them from a phone or tablet. Navigation wasn’t just a chore, it was downright painful.

Everything is much more streamlined now, anchored in good UI practices, and optimized for all kinds of screen sizes. We have Javascript to thank for that last part. It’s the magic language that turns boring static pages into fast, dynamic experiences.

In short, JS is excellent when you’re optimizing a website for humans. Bots, on the other hand, don’t deal with it as well. In fact, basic web scrapers can’t extract any HTML from dynamic websites without extra functionalities. Don’t worry, we’ll cover why that is and how to overcome the problem in this article.

A website doesn’t need Javascript. You can get away with only using HTML and CSS (or even just HTML if you want that 80s vibe). So why do people go the extra step of adding JS? Well, you’re about to find out.

Why do websites use Javascript?

Websites, much like homes, need a solid foundation. The very ground of this foundation is HTML code. By adding some tags and elements, you can use HTML to build and arrange sections, headers, links, and so on.

There are very few things you cannot do with HTML code when building a website. The anatomy of an HTML element consists of an opening tag, a closing tag, and the content in between. The website will show the information between these two tags according to the format they dictate.

By learning this simple coding style, you will be able to add headers, links, pictures, and much more to your website. Later on, you can use CSS to specify which styles apply to each element.

CSS, short for Cascading Style Sheets, is the pizzazz to your HTML. If the HTML is your structure, CSS is the decoration. It allows you to change colors, fonts, and page layouts throughout the page.

At this point, the website is good to go, if a bit flat. It can also suffer long loading times if you put too much data on too few pages or become tedious to navigate if you spread the content over too many pages.

So, it’s time to enhance the experience. Javascript is like the home’s utilities, it’s not crucial for the structure, but it makes a massive difference for whoever lives there.

JavaScript is mainly featured in web browsers and web apps, but it’s one of the most popular languages at the moment, and you can find it in software, servers, and embedded hardware controls.  

Here are a few examples of the many things you can use it for:

  • Audio and video players on a website
  • Animations
  • Drop-downs
  • Zooming in and out of photos
  • Gliding through images on a homepage
  • Creating confirmation boxes

Various JavaScript frameworks, such as AngularJS, ReactJS, and Node.js, are accessible on the web. You may decrease the amount of time necessary to create JS-based sites and apps by using these frameworks. JavaScript makes it simple for developers to create apps at scale. It makes the entire process of making large-scale web applications much more accessible.

As of late, many websites have become increasingly complex, and there’s a sudden need for statefulness in which the client’s data and settings are saved.

What is statefulness in web design?

A stateful system is a dynamic component in the sense that it remembers important events as state data and adapts the website according to it. It’s easier to understand with an example:

Bob accesses a website and signs up for an account. The system will remember his login and remember his state the next time he accesses the website. This way, Bob will not have to go to the login page because the website will automatically redirect him to the site’s members-only section.

Behind the scenes, a process creates an intermediary system that remembers the user details and automatically redirects him to the correct server or website.

On the other hand, a stateless system will not remember nor adapt, and will send the user to the login page and require him to reenter his credentials every time.

This principle can apply to any part of web design. Whatever you modify in the body, the state will follow accordingly. It manipulates a myriad of components that show up on the web page. Statefulness allows the website to store user-specific information to offer a personalized experience (access rights), including history interaction and saved settings.

Web design allows you to store info about your users on a server, while browser storage can still remember data but only up to the end of the session.

How does Javascript affect web scraping?

Javascript is a straightforward programming language that was designed to give dynamic functionality to websites within the browser. When a web page is loaded, its JS code is executed by the browser's Javascript Engine and turned into machine-readable code. While this reduces load time, dynamically modified websites can get in the way of web scraping.

Basic scrapers make an HTTP request to the website and store the content in the response. Under normal circumstances, that response will contain the page’s HTML code. Dynamic websites, however, return Javascript, which doesn’t have any valuable data.

Moreover, plenty of websites can detect whether the visitor can execute Javascript or not. Since average users browse the internet via a browser, they can’t execute JS, making it clear that they’re not using a browser. From there, it’s pretty clear for the websites that a bot and not a human is visiting it. This usually results in the bot’s IP getting blocked.

In short, websites that use JS can’t be scraped without the proper tools, and scrapers that can’t execute JS are a lot easier to catch than those who can.

How do web scrapers deal with Javascript?

Luckily, there’s a solution: headless browsers. These programs are essentially the same as regular browsers, with the same capabilities but lacking standard graphical UI. So, to navigate via a headless browser, you have to use the command line instead. While they’re primarily used for testing apps and websites, they can also execute Javascript code, making them ideal addons for web scrapers.

Once the headless browser handles the JS code, the website will send regular HTML, the data you actually want.

Another advantage headless browsers have over others is their speed. Since it doesn’t have to bother with the GUI, loading JS or CSS, it can process pages a lot faster, which is excellent for web scraping since it doesn’t slow down the bot too much.

If you want a DIY data extraction solution, there are two favored programming languages: Python and Node.js.

Python and Selenium

If you choose Python, the go-to library for JS rendering is Selenium. It’s a reliable option for executing Javascript, interacting with buttons, scrolling, and filling online forms. It is mainly used for open-source projects in browser automation. The WebDriver protocol controls browsers like Chrome and Firefox and can be run both remotely and locally.

Originally built as a tool for cross-browser testing, Selenium has quickly become a well-rounded collection of tools for web browser automation. Since many websites are constructed as Single Page Applications that spam CAPTCHAs even to real users, extracting data is starting to sound more and more like a daunting task due to the hypervigilance around bot detection.

With Selenium, the bot can read and execute Javascript code so that you have access to the HTML, fill in forms so that you can log into websites, scroll down a web page, and imitate clicks.

But if you’re scraping in Python, don’t just stop at Selenium. You can follow up with the BeautifulSoup library that makes HTML and XML parsing a breeze and then get Pandas for extracting and storing your data to a csv file.

Node.js and Puppeteer

Puppeteer is a Node.js package that lets you operate headless Chrome or Chromium and integrate the DevTools protocol. The Chrome DevTools team and a fantastic open-source community look after it.

This solution will help you manage a web scraper in the context of a website’s ever-changing structure. The main hurdle of scraping is that the tools require constant updates to adapt and not be restricted by the servers.

What can Node.js do? It aids Javascript in running both client and server-side for free, all while creating network applications a lot faster.

But let’s focus on the web scraping star. Puppeteer allows you to handle a web browser manually — everything from completing forms and taking screenshots to automating UI tests.

If you haven’t worked with these libraries before or just beginning your web scraping journey, I understand how all this can seem intimidating. However, there is an even more convenient solution that does all the work for you: an API.

Also known as Application Programming Interface, APIs allow the users to get the data straight away. By making a request to the API endpoint, the app will give you the data you need. On top of that, it automatically comes in JSON format.

The greatest advantage of using an API is how simple it is to connect it with your other software products or scripts. With only a few lines of code, you can feed the scraped data straight to other apps after receiving your unique API key and reading the documentation.

Here’s a quick rundown of everything WebScrapingAPI does for you:

  • Executes Javascript and accesses the HTML code behind dynamic web pages
  • uses a rotating proxy pool containing hundreds of thousands of residential and datacenter IPs to mask your activity
  • Offers access to the request headers so you can customize your API calls and ensure that the scraper is indistinguishable from normal visitors
  • Employs anti-fingerprinting and anti-captcha features
  • Returns the data already parsed into a JSON file.

A hassle-free web scraping solution

From web design, HTML, CSS, Javascript to headless browsers, the World Wide Web always comes full circle — free-circulating data. That’s why the Internet exists in the first place. What better way to make use of the heaps of content than data collection? After all, where would businesses, developers, and even people, in general, be today without access to valuable information?

It is truly what drives us all. Now that you understand how Javascript affects today’s Internet, you’re better prepared to start scraping, and I hope that you do just that. If you’re running short on time, consider trying our own solution, WebScrapingAPI, for free. The trial period lasts for two weeks, and you get access to all the essential features like JS rendering and residential proxies.

Check out what the API can do and, if you’re not yet convinced, hit up our incredibly responsive customer support for guidance.

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