Node.js and Puppeteer Web Scraping: Difference between revisions
From WickyWiki
m →Code |
m →Code |
||
| Line 68: | Line 68: | ||
// Set screen size | // Set screen size | ||
await page.setViewport({width: 1300, height: 1000}); | await page.setViewport({width: 1300, height: 1000}); | ||
console.log("Type and execute search query"); | |||
// Wait for an element using a CSS selector, | // Wait for an element using a CSS selector, | ||
| Line 78: | Line 80: | ||
await page.keyboard.press('Enter', {delay: 1000}); | await page.keyboard.press('Enter', {delay: 1000}); | ||
// Show url | |||
const url = await page.evaluate(() => { | |||
return window.location.href; | |||
}); | |||
console.log("url:", url); | |||
// Count | // Count results | ||
const | const results1 = await page.$$('a[data-testid="result-title-a"]'); | ||
console.log(" | console.log("Found search results:", results1.length); | ||
//Click button with text "More results" | // Click button with text "More results" | ||
console.log("Search more-button and click"); | |||
await page.$$eval('button', buttons => { | await page.$$eval('button', buttons => { | ||
for (const btn of buttons) { | for (const btn of buttons) { | ||
| Line 95: | Line 103: | ||
); | ); | ||
// | // Wait | ||
const | await sleep(500); | ||
// Count results | |||
console.log(" | const results2 = await page.$$('a[data-testid="result-title-a"]'); | ||
console.log("Found search results:", results2.length); | |||
// Show local storage | // Show local storage | ||
Revision as of 10:38, 2 September 2025
Puppeteer uses headless Chrome browser instance but making it visible helps to show what you are doing. Also, you can use DevTools (F12) the see what is happening.
This setup has been used for Windows but should also be possible for Linux.
I first tried "Puphpeteer", which is a PHP library that is made on top of Puppeteer. This however, turns out to result in a wobbly stack of badly maintained components.
Generally
- Node.js / Puppeteer: https://pptr.dev/
- About CSS selector expressions: https://scrapeops.io/puppeteer-web-scraping-playbook/Node.js-puppeteer-find-elements-css-selector/
Windows install of Node.js
The Node.js installer (msi) has an option to install dependencies, you can try it but it is quite terrible.
- PowerShell is used during installation
- Chocolatey Package manager https://chocolatey.org/install is installed and used for further installation
- Visual Studio Build Tools 2022 (for its 64 bit C++ compiler) is installed
- Python 3.13.7 is installed
- Node.js is installed with Node.js package manager npm
There are other options, this is my selection.
Start new Node.js project
Start terminal
cd D:\Programs\Nodejs\ mkdir puppeteer-project cd puppeteer-project npm init
Install Puppeteer
(in terminal)
cd puppeteer-project npm install puppeteer
Code
import puppeteer from 'puppeteer';
function sleep(ms) {
return new Promise(resolve => setTimeout(resolve, ms));
}
(async () => {
// Open a browser {headless:false} means the browser will be visible
const browser = await puppeteer.launch({headless: false});
const page = await browser.newPage();
// Navigate to a URL
await page.goto('https://duckduckgo.com/', {delay: 500});
// Navigate to a file (example)
//page.goto('file:///'+import.meta.dirname+'/test.html');
// Set screen size
await page.setViewport({width: 1300, height: 1000});
console.log("Type and execute search query");
// Wait for an element using a CSS selector,
const selector1 = 'input[id="searchbox_input"]';
await page.waitForSelector(selector1);
// Select and type
await page.type(selector1, 'Node.js puppeteer examples', {delay: 5});
// Press Enter
await page.keyboard.press('Enter', {delay: 1000});
// Show url
const url = await page.evaluate(() => {
return window.location.href;
});
console.log("url:", url);
// Count results
const results1 = await page.$$('a[data-testid="result-title-a"]');
console.log("Found search results:", results1.length);
// Click button with text "More results"
console.log("Search more-button and click");
await page.$$eval('button', buttons => {
for (const btn of buttons) {
if ( btn.innerText.toLowerCase().includes('more results') ) {
btn.scrollIntoView();
btn.click();
break;
}
}
}
);
// Wait
await sleep(500);
// Count results
const results2 = await page.$$('a[data-testid="result-title-a"]');
console.log("Found search results:", results2.length);
// Show local storage
const localStorage = await page.evaluate(() => {
return localStorage;
});
console.log("localStorage:", JSON.stringify(localStorage));
// Show cookies
const cookies = await browser.cookies();
console.log("cookies:", cookies);
// Wait 5mins
console.log("Press CTRL+C to close ..");
await sleep(5*60*1000);
// Close browser
await browser.close();
})();
Execute
(in terminal)
cd D:\Programs\Nodejs\ cd puppeteer-project node app-test.js