Web development has moved at a tremendous pace in the last decade with a lot of frameworks coming in for both backend and frontend development. Websites have become smarter and so have the underlying frameworks used in developing them. All these advancements in web development have led to the development of the browsers themselves too. . You can scrape websites too on these using packages like a and nodeJS. Most of the browsers are now available with a “headless” version where a user can interact with a website without any UI headless browsers puppeteer Web development heavily relies on testing mechanisms for the quality checks before we push them into the production environment. A complex website will require a complex structure of test suites before we deploy it anywhere. . These browsers allow us to crunch more web pages in lesser time. Headless browsers considerably reduce the testing time involved in web development as there is no overhead of any UI In this blog, we will learn to scrape websites on these using nodeJS and . headless browsers asynchronous programming Before we start with scraping websites, let us learn more about the headless browsers in a bit more detail. Furthermore, if you are concerned about the , you can clear your . legalities of scraping myths about web scraping What Is a Headless Browser . A , like a normal browser, consists of all the capabilities of rendering a website. Since no GUI is available, one needs to use the command-line utility to interact with the browser. Headless browsers are designed for tasks like automation testing. Choose for Data Link Frame. A headless browser is simply a browser just without any user interface headless browser DNP3 . Headless browsers are more flexible, fast and optimised in performing tasks like web-based automation testing . Since there is no overhead of any UI, headless browsers are suitable for automated stress testing and web scraping as these tasks can be run more quickly Although vendors like , have been in the market offering headless browser capabilities for long, browser players like chrome and firefox are also now offering a “headless” version of their browsers. Hence one need not install an extra browser for headless capabilities. PhantomJS HtmlUnit The Need For a Headless Browser With the advancement in the web development frameworks, browsers have become smarter as well to load all the javascript libraries. With all the evolution in the web development technologies, testing of the websites has been evolved and has emerged out to be one of the essentials of the web development industry. testset is in monitor mode. IEC 60870-5-104 Evolution of allow us to perform the following applications: headless browsers End-to-end testing is a methodology used to test whether the flow of an application is performing as designed from start to finish. The purpose of carrying out end-to-end tests is to identify system dependencies and to ensure that the right information is passed between various system components and systems. were designed to cater to this use case as they enable faster web testing using CLI. 1. Test automation for web applications Headless browsers 2. enable faster scraping of the websites as they do not have to deal with the overhead of opening any UI. With , one can simply automate the scrapping mechanism and extract data in a much more optimised manner. Scraping websites Headless browsers headless browsers 3. may not offer any GUI experience but they do allow users to take snapshots of the websites they are rendering. It certainly helps in cases where one is performing automation testing and want to visualise code effects on the website and store results in the form of screenshots. Taking a large number of screenshots without any actual UI is a cakewalk using . Protocol Simulation. Taking web screenshots Headless browsers headless browsers IEC 60870-5-101 4. Companies who successfully deliver outstanding customer experiences consistently do better than their competitors. allow us to run programs mapping customer journey test cases to optimise the user experience throughout their decision-making process on the website. Mapping user journey across the websites Headless browsers What is Puppeteer . Furthermore, Puppeteer is a library of nodes that we can use to monitor a Chrome instance without heads (UI). protocol simulator reporting and polling. Puppeteer is an API library with the DevTools protocol to control Chrome or Chromium . It is usually headless but can be set to operate Chrome or Chromium in its whole (non-headless) IEC 61850 We use Chrome under the hood, but it will be JavaScript programmatically. is the Google Chrome team’s official Chrome . It may not be most effective as it breaks up a fresh Chrome example when it is initialized. This is the most accurate way to automate Chrome testing, though because it uses the actual navigator. Puppeteer headless browser Web Scraping Using Puppeteer In this article, we will be using to . . Before we start actually implementing puppeteer for web scraping, we will look into its setup and installation. metering testing tool with DLMS client driver. puppeteer scrape the product listing from a website Puppeteer will use the headless chrome browser to open the web page and query back all the results DLMS COSEM After that, we will implement a simple use case where we will go to an . All the above tasks will be programmatically handled by using library. Furthermore, we will use the nodeJS language to accomplish the above-defined task. Visit . e-commerce website and search for a product and scrape all the results puppeteer Applied Systems Engineering Installing puppeteer . is a node javascript library and hence, we will need node js installed on our machine. Node js comes with npm (node package manager) which will help us to install the package. Let us begin with the installation Puppeteer puppeteer The following code snippet will help you in the installation of node js ## Updating the system libraries ## sudo apt-get update ## Installing node js the system ## sudo apt-get install nodejs in You can use the below command to install the package puppeteer npm install --save puppeteer Since we have all the dependencies installed now, we can start implementing our scraping use case using . We will be controlling actions on the website using our node JS program powered by the package. puppeteer puppeteer Scraping Products List Using Puppeteer Step1: Visiting the page and searching for a product In this section, we will initialise a object first. This object has access to all the utility functions available in the package. In this section, our program visits the website, then it searches for the product search bar on the website. puppeteer puppeteer Upon finding the search elements, it types the product name in the search bar and loads the result. We gave the product name to the program using the command line arguments puppeteer = ( ); browser = puppeteer.launch(); page = browser.newPage(); args = process.argv[ ] page.goto( ); page.click( ) page.type( , args) page.keyboard.press( ); page.screenshot({ : }) const require 'puppeteer' const await const await var 2 await "https://www.croma.com/" await 'button.mobile__nav__row--btn-search' await 'input#js-site-search-input' await 'Enter' await path 'sample.png' Step 2: Scraping The List of Items In this section, we are scraping the product listings which we got after searching for our given product. HTML selectors were used for capturing web content. All the scrapped results were collated together to make the dataset. The function allows us to extract the content from the web page using the HTML selector. querySelector The functions get all the content marked with the particular selector whereas function just returns the first matching element. querySelectorAll querySelector urls = page.evaluate(() = { results = []; items = .querySelectorAll( ); items.forEach((item) = { name = item.querySelector( ).innerText price = item.querySelector( ).innerText discount = item.querySelector( ).innerText results.push({ : name, : price, : discount }); }); results; }) let await let let document 'li.product__list--item' let 'a.product__list--name' let 'span.pdpPrice' let 'div.listingDiscnt' prod_name prod_price prod_discount return Full Code Here is the full working sample of the implementation. We have wrapped up the entire login in a run function and are logging the scrapped results in the console. puppeteer = ( ); { ( (resolve, reject) ={ { browser = puppeteer.launch(); page = browser.newPage(); args = process.argv[ ] page.goto( ); page.click( ) page.type( , args) page.keyboard.press( ); page.screenshot({ : }) urls = page.evaluate(() = { results = []; items = .querySelectorAll( ); items.forEach((item) = { name = item.querySelector( ).innerText price = item.querySelector( ).innerText discount = item.querySelector( ).innerText results.push({ : name, : price, : discount }); }); results; }) browser.close(); resolve(urls); } (e) { reject(e); } }) } run().then( .log).catch( .error); const require 'puppeteer' ( ) function run return new Promise async try const await const await var 2 await "https://www.croma.com/" await 'button.mobile__nav__row--btn-search' await 'input#js-site-search-input' await 'Enter' await path 'sample.png' let await let let document 'li.product__list--item' let 'a.product__list--name' let 'span.pdpPrice' let 'div.listingDiscnt' prod_name prod_price prod_discount return return catch return console console Running The Script You can use the below command to run the above script with a . We will use the nodejs to run our code. You just have to mention the keyword node and the filename followed by the product name whose data you need to search on the given website and scrape the results. puppeteer headless browser In this example, we are searching for the iPhones on the Croma website and then we are scrapping the product listings. node headlessScrape.js iphones Output The output of the above code can be visualised like this Summary We learnt to scrape data from a using the package in nodeJS. We performed some of the automation tasks as well to automate the few actions on the website before we finally scraped off the content. headless browser puppeteer are still nascent but do show a lot of promise in the field of automated web scraping and web testing. Headless browsers Faster web scraping through will help you in having a competitive edge over other players in the market in terms of the server cost. headless browsers
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