Web scraping, also known as Web Data Extraction or Web Harvesting, is the process of gathering information from all over the web. Today, data works as oxygen for startups and freelancers seeking to start a business or project in any domain. Suppose you need to get the price of a product on an eCommerce website. It’s easy to find, but now let’s imagine you have to run through this process for thousands of products across many eCommerce websites. Doing it manually is not a bad option at all.
Because of the massive improvements, it has made and the introduction of the runtime known as NodeJS, Web scraping JavaScript has been one of the most popular and widely used languages. Web Scraping Javascript now gets the correct tools, whether a web or a mobile application. This article will demonstrate how a simple scraping tool to match most of your requirements is feasible thanks to NodeJS’s robust ecosystem.
How to create a web scraper with Javascript?
You should solve a set of factors to build a fully-featured web scraper:
- how to extract data (from the website to retrieve requested data)
- how to parse data ( only the information that is asked for)
- how to provision or store parsed data
Let’s consider a basic NodeJS web scraper that will utilize the site’s title text to decide the title text. The example above employs the Axios library to fetch the HTML content from example.com, the regular expression to parse the title, and the HTTP module to serve the result via the web service endpoint. Various libraries are available below to provide multiple aspects of Javascript web scraper and reduce your codebase.
HTML parsing: Cheerio and JSDOM
The retrieved website content is usually an HTML code of the entire web page. Still, the web scraping process is typically used to obtain specific information from the entire page content, such as product title, price, and image URL.
At the beginning of this article, we’ve applied the standard expression extract the title from the content of example.com. You can use this method to analyze strict-structured data such as telephone numbers, emails, etc. For common cases, it is unnecessarily complicated.
The libraries listed below help build a well-structured, maintainable, and readable codebase without RegExp.
Making requests: HTTP clients
The HTTP client is a tool that can be used to connect with servers using the HTTP protocol. It’s a module or library that can send requests and get responses from the servers, to phrase it another way.
An HTTP client is usually only used to cover data extraction from the website: it allows issuing a request to a web server for receiving HTML content, and a response contains the desired HTML. HTTP clients are frequently used in more complex data extraction tools under the hood.
NodeJS comes with various options: Axios, SuperAgent, Got, and Node Fetch, but we’ll only review the two most popular (based on the Github stars count).
Conclusion Paragraph:
When you are experiencing any difficulties in a scraping process, you can always refer to this scraping guide. If things become more complicated, you can run the browser with the following false: false to ease things up because you will understand what is happening, and debugging will be easier. Prepare to employ proxies to cloak your public IP; rotating proxies will be requested if the target website bans IP addresses. You’ll soon be able to approach any web scraping in a modern and intelligent way. Putting all Javascript scraping stacks together in one article will be challenging, but it should be an excellent primer for the next steps in web scraping. The NodeJS web scraping ecosystem has a variety of abilities for performing and solving various data mining tasks.
Addsion Is a Blogger and an SEO professional. Co-founder of dsnews.co.uk, I have 2 years of experience in SEO & 1 year of Successful blogging @ dsnews.co.uk. I have a passion for SEO & Blogging, Affiliate marketer & also interested to invest on profitable stocks.
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