How to invoke Chrome Node Screenshot from the console? - google-chrome

I know you can capture a single html node vial the command prompt, but is it possible to do this programmatically from the console similar to Puppeteer? I'd like to loop all elements on a page and capture them for occasional one-off projects where I don't want to set up a full auth process in puppeteer.
I'm referring to this functionality:
But executed from the console like during a foreach or something like that.
See the puppeteer reference here.
Something to the effect of this:
$x("//*[contains(#class, 'special-class-name')]").forEach((el)=> el.screenshot())

I just made a script that take a screenshot every submit button in Google main page. Just take a look and take some inspiration from it.
const puppeteer = require('puppeteer')
;(async () => {
const browser = await puppeteer.launch({
headless:false,
defaultViewport:null,
devtools: true,
args: ['--window-size=1920,1170','--window-position=0,0']
})
const page = (await browser.pages())[0]
const open = await page.goto ( 'https://www.google.com' )
const submit = await page.$$('input[type="submit"]')
const length = submit.length
let num = 0
const shot = submit.forEach( async elemHandle => {
num++
await elemHandle.screenshot({
path : `${Date.now()}_${num}.png`
})
})
})()

You can use ElementHandle.screenshot() to take a screenshot of a specific element on the page. The ElementHandle can be obtained from Page.$(selector) or Page.$$(selector) if you want to return multiple results.
const browser = await puppeteer.launch({ headless: true });
const page = await browser.newPage();
await page.goto("https://stackoverflow.com/questions/50715164");
const userInfo = await page.$(".user-info");
await userInfo.screenshot({ path: "userInfo.png" });
The output image after executing the code:

Related

how to load extension using puppeteer.connect() method

i use gologin service. gologin is a browser antidetect service where I can fake my browser identity / can manage browser fingerprint.
so I can freely do web-scraping without being detected.
in this case I want to be able to load my extension into that browser using the puppeteer.connect() method.
here's the code:
const puppeteer = require('puppeteer-core');
const GoLogin = require('gologin');
(async () => {
const GL = new GoLogin({
token: 'yU0token',
profile_id: 'yU0Pr0f1leiD',
});
const { status, wsUrl } = await GL.start();
const browser = await puppeteer.connect({
browserWSEndpoint: wsUrl.toString(),
ignoreHTTPSErrors: true,
});
const page = await browser.newPage();
await page.goto('https://myip.link/mini');
console.log(await page.content());
await browser.close();
await GL.stop();
})();
I don't know how. please help me, so i can load my extension using this puppeteer.connect()
Assume your wish is loading chrome-extension into your puppeteer browser.
Find chrome-extension Working Directory Where does Chrome store extensions?
Find your extension ID by go to chrome://extensions/
Sample code:
const puppeteer = require('puppeteer-core');
const MY_EXTENSION_PATH = '~/Library/Application Support/Google/Chrome/Default/Extensions/cdockenadnadldjbbgcallicgledbeoc/0.3.38_0'
async function loadExtension() {
return puppeteer.launch({
headless: 0,
args: [
`--disable-extensions-except=${MY_EXTENSION_PATH}`,
`--load-extension=${MY_EXTENSION_PATH}`,
],
});
}

Node js speed up puppeteer html to pdf

I have a node js application that creates dynamic content which I want users to download.
static async downloadPDF(res, html, filename) {
const puppeteer = require('puppeteer');
const browser = await puppeteer.launch({
headless: true
});
const page = await browser.newPage()
await page.setContent(html, {
waitUntil: 'domcontentloaded'
})
const pdfBuffer = await page.pdf({
format: 'A4'
});
res.set("Content-Disposition", "attachment;filename=" + filename + ".pdf");
res.setHeader("Content-Type", "application/pdf");
res.send(pdfBuffer);
await browser.close()
}
Is there a way to speed up the whole process since it takes about 10 seconds to create a pdf file of size about 100kb?
I read somewhere that I can launch the headless browser once then I will only be creating a new page instead of launching a browser every time I request for the file.
I cannot find out a correct way of doing it.
You could move page creation to a util and hoist it to re-use it.
const puppeteer = require('puppeteer');
let page;
const getPage = async () => {
if (page) return page;
const browser = await puppeteer.launch({
headless: true,
});
page = await browser.newPage();
return page;
};
.
const getPage = require('./getPage');
static async downloadPDF(res, html, filename) {
const page = await getPage()
}
Yes, no reason to launch browser every time. You can set puppeter to call new url and get content. Without every time launching, it would be more faster.
How implement this ? Cut your function to three steps :
Create a browser instance. No matter headless or not. If you run app in X environment, you can launch a window, to see what your puppetter do
Create a function code, that will do main task in cycle.
After block is done, call await page.goto(url) ( where "page" is the instance of browser.newPage() ) and run your function again.
This is one of possible solution in function style code :
Create a instnces :
const browser = await puppeteer.launch( {'headless' : false });
const page = await browser.newPage();
page.setViewport({'width' : 1280, 'height' : 1024 });
I put it in realtime async function like (async ()=>{})();
Gets a data
Im my case, a set of urls was in mongo db, after getting it, I had ran a cycle :
for( const entrie of entries)
{
const url = entrie[1];
const id = entrie[0];
await get_aplicants_data(page,url,id,collection);
}
In get_aplicants_data() I had realized a logic according a loaded page :
await page.goto(url); // Going to url
.... code to prcess page data
Also you can load url in cycle and then put in your logic
Hope I have given you some help )

Avoid puppeteer detection

Is there any way to avoid being detected by a website that I am using puppeteer? I just can't navigate around the https://www.footlocker.ca/ website using puppeteer. I have tried using stealth plugin and random user-agents to no avail.
Any advice on what else I can try?
This website use navigator.webdriver to check if you are real user or bot. so you can use the code below to delete navigator.webdriver value. docs.
const puppeteer = require("puppeteer");
(async () => {
const browser = await puppeteer.launch({
headless: false,
});
const page = await browser.newPage();
await page.evaluateOnNewDocument(() => {
delete navigator.__proto__.webdriver;
});
await page.goto("https://www.footlocker.ca", {
waitUntil: "domcontentloaded",
});
})();

Using puppeteer get a selector from an input label

So, I have a front end in React.js or Ember.js - not sure. I'm just trying to automate some testing for it. When looking at the HTML in the Chrome Dev Tools, I see
<label class="MuiFormLabel-root-16 MuiInputLabel-root-5 MuiInputLabel-formControl-10 MuiInputLabel-animated-13 MuiInputLabel-outlined-15" data-shrink="false">Username</label>
This is set in an iframe (which isn't too important for this issue). I'm trying to get the ElementHandler using the puppeteer function
frame.$(selector)
How do I get the selector given
Username
I've tried a few things, but with little success.
If I understand correctly, you need to find an element by its text content. If so, these are at least two ways:
const puppeteer = require('puppeteer');
(async function main() {
try {
const browser = await puppeteer.launch(); // { headless: false, defaultViewport: null, args: ['--lang=en'] }
const [page] = await browser.pages();
await page.goto('https://example.org/');
const element1 = await page.evaluateHandle(() => {
return [...document.querySelectorAll('h1')].find(h1 => h1.innerText === 'Example Domain');
});
console.log(await (await element1.getProperty('outerHTML')).jsonValue());
const [element2] = await page.$x('//h1[text()="Example Domain"]');
console.log(await (await element2.getProperty('outerHTML')).jsonValue());
await browser.close();
} catch (err) {
console.error(err);
}
})();
My solution was to place HTML data attributes in the front end code so that I can easily select them.

Can Cypress expose function to global object?

I learned that puppeteer can add a function on the page's window object like this:
const browser = await puppeteer.launch();
const page = await browser.newPage();
await page.exposeFunction('md5', text =>
crypto.createHash('md5').update(text).digest('hex')
);
await page.evaluate(async () => {
// use window.md5 to compute hashes
const myString = 'PUPPETEER';
const myHash = await window.md5(myString);
console.log(`md5 of ${myString} is ${myHash}`);
});
So I'm wondering is there any way that Cypress can attach functions to window function like puppeteer does?