Web scraping using javascript8/1/2023 We have now confirmed this is the API request we're interested in scraping. With some careful inspection, we can see that the second item in the resultSets entry in this response matches the data for our table. Recalling the HTML we inspected from earlier, we were looking for a dataset named "Base" and the second set ( sets from before) in it to find our table data. The JSON response from the API request we found, truncated for readability Let's head on over to and find the page with the stats we care about, in this case LeBron's player page: ![]() Step 1: Check if the data is loaded dynamically Our goal will be to write a script that will save LeBron James' year-over-year career stats. Okay with some preliminary understanding of data formats under our belt, it's time to take a stab at scraping some real data. We'll use as our case study to learn these techniques. In this case, we'll go over a method of intercepting these API requests and work with their JSON payloads directly via a script written in Node.js. Case 1 – Using APIs DirectlyĪ very common flow that web applications use to load their data is to have JavaScript make asynchronous requests ( AJAX) to an API server (typically REST or GraphQL) and receive their data back in JSON format, which then gets rendered to the screen. Learning to read and understand this format will go a long way to helping you work with data on the web. Note these instructions were written with Chrome 78 and will likely vary slightly with different browsers. ![]() So without further adieu, let's begin with a quick primer on CSV vs JSON. We'll even try out curl and jq on the command line for a bit. I'll go through the way I investigate what is rendered on the page to figure out what to scrape, how to search through network requests to find relevant API calls, and how to automate the scraping process through scripts written in Node.js. There are several different ways to scrape, each with their own advantages and disadvantages and I'm going to cover three of them in this article:įor each of these three cases, I'll use real websites as examples (, , and respectively) to help ground the process. Familiarity with JavaScript is assumed.Whether you're a student, researcher, journalist, or just plain interested in some data you've found on the internet, it can be really handy to know how to automatically save this data for later analysis, a process commonly known as "scraping". This video is ideal for JavaScript programmers, web administrators, security professionals or anyone who wants to perform web scraping. To fully benefit from the coverage included in this course, you will need: Instructions and Navigation Assumed Knowledge Learn to save the result to the cloud with S3 (AWS) using a NodeJS server.Find out how to automate these actions with JavaScript packages.Extract data from web pages with simple JavaScript programming and libraries such as CasperJS, Cheerio, and express.js using a realistic example.Understand how to create a web scraping tool using JavaScript and NodeJS.Build a simple and powerful JavaScript scraping script.The code bundle for this video course is available at - What You Will Learn You'll find out how to automate these actions with JavaScript packages such as Cheerio and CasperJS.īy the end of the book, you will have explored testing websites with scrapers, remote scraping, best practices, working with images, and many other relevant topics. You'll determine when and how to scrape data from a JavaScript-dependent website using JavaScript scraping libraries. After covering the basics, you'll get hands-on practice building more sophisticated scripts. In the early chapters, you'll see how to extract data from static web pages. This video is the ultimate guide to using the latest features of JavaScript and Node.js to scrape data from websites. ![]() It contains all the supporting project files necessary to work through the video course from start to finish. This is the code repository for Learning Web Scraping with JavaScript, published by Packt.
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