Develop Reference

How to select specific button in puppeteer

So I'm building a program that scrapes Poshmark webpages and extracts the usernames of each seller on the page!
I want it to go through every page using the 'next' button, but theres 6 buttons all with the same class name...
Heres the link: https://poshmark.com/category/Men-Jackets_&_Coats?sort_by=like_count&all_size=true&my_size=false
(In my google chrome this page has an infinite scroll (hence the scrollToBottom async function i started writing) but i realized inside puppeteer's chrome it has 'next page' buttons.)
The window displays page 1-5 and then the 'next page' button.
The problem is that all of the buttons share the same html class name, so I'm confused on how to differentiate.
const e = require('express');
const puppeteer = require('puppeteer');
const url = "https://poshmark.com/category/Men-Jackets_&_Coats?sort_by=like_count&all_size=true&my_size=false";
let usernames = [];
const initItemArea = async (page) => {
const itemArea = await page.evaluate(() => {
return Array.from(document.querySelectorAll('.tc--g.m--l--1.ellipses')).map(x => x.textContent);
});
}
const pushToArray = async (itemArea, page) => {
itemArea.forEach(function (element) {
//console.log('username: ', $(element).text());
usernames.push(element);
});
};
const scrollToBottom = async (itemArea, page) => {
while (true) {
previousHeight = await page.evaluate('document.body.scrollHeight');
await page.evaluate('window.scrollTo(0, document.body.scrollHeight)');
await page.waitForFunction(`document.body.scrollHeight > ${previousHeight}`);
await new Promise((resolve) => setTimeout(resolve, 1000));
await page.screenshot({path : "ss.png"})
}
};
const gotoNextPage = async (page) => {
await page.waitForSelector(".button.btn.btn--pagination");
const nextButton = await page.evaluate((page) => {
document.querySelector(".button.btn.btn--pagination")
});
await page.click(nextButton);
console.log('Next Page Loading')
};
async function main() {
const client = await puppeteer.launch({
headless: false,
executablePath: "/Applications/Google Chrome.app/Contents/MacOS/Google Chrome"
});
const page = await client.newPage();
await page.goto(url);
await page.waitForSelector(".tc--g.m--l--1.ellipses");
const itemArea = await page.evaluate(() => {
return Array.from(document.querySelectorAll('.tc--g.m--l--1.ellipses')).map(x => x.textContent);
});
gotoNextPage(page)
};
main();
Currently, my gotoNextPage function doesnt even find the button, so i thought i'd entered the selector wrong...
Then when I went to find the selector, I realized all buttons have the same one anyway...
My html knowledge is basically nonexistent, but I want to finish this project out. All help is very appreciated.
Bonus: my initPageArea function doesn't work when I call as a function like that, so I hardcoded it into main()...
I'll be diving deep into this problem later on, as I've seen it before, but any quick answers / direction would be awesome.
Thanks a lot.

you can try selecting the buttons using their position in the page.
For example, you can select the first button using the following CSS selector:
.button.btn.btn--pagination:nth-child(1)
to select the second button:
.button.btn.btn--pagination:nth-child(2)
Got the idea? :)
you can refactor your gotoNextPage function to use this approach, consider this example:
const gotoNextPage = async (page, buttonIndex) => {
await page.waitForSelector(".button.btn.btn--pagination");
// Select the button using its position in the page
const nextButton = await page.evaluate((buttonIndex) => {
return document.querySelector(`.button.btn.btn--pagination:nth-child(${buttonIndex})`);
}, buttonIndex);
// Click on the button
await page.click(nextButton);
console.log("Next Page Loading");
};

Whenever you're messing with buttons and scroll, it's a good idea to think about where the data is coming from. It's usually being delivered to the front-end via a JSON API, so you might as well try to hit that API directly rather than mess with the DOM.
const url = maxId => `https://poshmark.com/vm-rest/channel_groups/category/channels/category/collections/post?request={%22filters%22:{%22department%22:%22Men%22,%22category_v2%22:%22Jackets_%26_Coats%22,%22inventory_status%22:[%22available%22]},%22sort_by%22:%22like_count%22,%22facets%22:[%22color%22,%22brand%22,%22size%22],%22experience%22:%22all%22,%22sizeSystem%22:%22us%22,%22max_id%22:%22${maxId}%22,%22count%22:%2248%22}&summarize=true&pm_version=226.1.0`;
(async () => {
const usernames = [];
for (let maxId = 1; maxId < 5 /* for testing */; maxId++) {
const response = await fetch(url(maxId)); // Node 18 or install node-fetch
if (!response.ok) {
throw Error(response.statusText);
}
const payload = await response.json();
if (payload.error) {
break;
}
usernames.push(...payload.data.map(e => e.creator_username));
}
console.log(usernames.slice(0, 10));
console.log("usernames.length", usernames.length);
})()
.catch(err => console.error(err));
The response blob has a ton of additional data.
I would add a significant delay between requests if I were to use code like this to avoid rate limiting/blocking.
If you're set on Puppeteer, something like this should work as well, although it's slower and I didn't have time to run to the end of the 5k (or more?) users:
const puppeteer = require("puppeteer"); // ^19.1.0
const url = "Your URL";
let browser;
(async () => {
browser = await puppeteer.launch();
const [page] = await browser.pages();
await page.goto(url, {waitUntil: "domcontentloaded"});
const usernames = [];
const sel = ".tc--g.m--l--1.ellipses";
for (;;) {
try {
await page.waitForSelector(sel);
const users = await page.$$eval(sel, els => {
const text = els.map(e => e.textContent);
els.forEach(el => el.remove());
return text;
});
console.log(users); // optional for debugging
usernames.push(...users);
await page.$$eval(
".btn--pagination",
els => els.find(el => el.textContent.includes("Next")).click()
);
}
catch (err) {
break;
}
}
console.log(usernames);
console.log(usernames.length);
})()
.catch(err => console.error(err))
.finally(() => browser?.close());
I don't think navigations are triggered by the "Next" button, so my strategy for detecting when a page transition has occurred involves destroying the current set of elements after scraping the usernames, then waiting until the next batch shows up. This may seem inelegant, but it's easy to implement and seems reliable, not making assumptions about the usernames themselves.
It's also possible to use Puppeteer and make or intercept API requests, armed with a fresh cookie. This is sort of halfway between the two extremes shown above. For example:
const puppeteer = require("puppeteer");
const url = "Your URL";
let browser;
(async () => {
browser = await puppeteer.launch();
const [page] = await browser.pages();
await page.goto(url, {waitUntil: "domcontentloaded"});
const usernames = await page.evaluate(async () => {
const url = maxId => `https://poshmark.com/vm-rest/channel_groups/category/channels/category/collections/post?request={%22filters%22:{%22department%22:%22Men%22,%22category_v2%22:%22Jackets_%26_Coats%22,%22inventory_status%22:[%22available%22]},%22sort_by%22:%22like_count%22,%22facets%22:[%22color%22,%22brand%22,%22size%22],%22experience%22:%22all%22,%22sizeSystem%22:%22us%22,%22max_id%22:%22${maxId}%22,%22count%22:%2248%22}&summarize=true&pm_version=226.1.0`;
const usernames = [];
try {
for (let maxId = 1; maxId < 5 /* for testing */; maxId++) {
const response = await fetch(url(maxId)); // node 18 or install node-fetch
if (!response.ok) {
throw Error(response.statusText);
break;
}
const json = await response.json();
if (json.error) {
break;
}
usernames.push(...json.data.map(e => e.creator_username));
}
}
catch (err) {
console.error(err);
}
return usernames;
});
console.log(usernames);
console.log("usernames.length", usernames.length);
})()
.catch(err => console.error(err))
.finally(() => browser?.close());
The above code limits to 4 requests to keep it simple and easy to validate.
Blocking images and other unnecessary resources can help speed the Puppeteer versions up, left as an exercise (or just use the direct fetch version shown at top).

When I try to web scrape a dynamic website, i get back an empty array

I am trying to web scrape a dynamic website with puppeteer, using this code:
const puppeteer = require('puppeteer');
async function getTokoPedia(){
const browser = await puppeteer.launch({ headless: false }); // for test disable the headlels mode,
const page = await browser.newPage();
await page.setViewport({ width: 1000, height: 926 });
await page.goto("https://store.401games.ca/collections/pokemon-singles",{waitUntil: 'networkidle2'});
console.log("start evaluate javascript")
var productNames = await page.evaluate(()=>{
var div = document.querySelectorAll('.info-container');
console.log(div) // console.log inside evaluate, will show on browser console not on node console
var productnames = []
div.forEach(element => {
var price = element.querySelector(' .fs-result-page-3sdl0h')
if(price != null){
productnames.push(price.innerText);
}
});
return productnames
})
console.log(productNames)
browser.close()
}
getTokoPedia();
However, upon running it, I get back an empty array. How can I fix this?

Two problems:
The elements you want are in a shadow root, so you have to pierce the root as described in Puppeteer not giving accurate HTML code for page with shadow roots.
The cards lazy-load, so you'd have to scroll down to be able to populate their data into the DOM.
But there's an easier way to get the initial set of data, which is in the static HTML as a JSON blob in var meta = {"products":...};. You can scrape it with a regex, as described in this tutorial.
Here's an example showing both approaches:
const puppeteer = require("puppeteer"); // ^14.1.1
let browser;
(async () => {
browser = await puppeteer.launch({headless: true});
const [page] = await browser.pages();
const url = "https://store.401games.ca/collections/pokemon-singles";
await page.goto(url, {waitUntil: "domcontentloaded"});
// here's the hard way for illustration:
const el = await page.waitForSelector("#fast-simon-serp-app");
await page.waitForFunction(({shadowRoot}) =>
shadowRoot.querySelector(".product-card .title")
, {}, el);
const items = await el.evaluate(({shadowRoot}) =>
[...shadowRoot.querySelectorAll(".product-card")]
.map(e => ({
title: e.querySelector(".title")?.textContent,
price: e.querySelector(".price")?.textContent,
}))
);
console.log(items); // just the first 6 or so
// TODO scroll the page to get the rest;
// I didn't bother implementing that...
// ...or do it the easy way:
const html = await page.content();
const pat = /^[\t ]*var meta = ({"products":[^\n]+);$/m;
const data = JSON.parse(html.match(pat)[1]);
console.log(JSON.stringify(data, null, 2));
})()
.catch(err => console.error(err))
.finally(() => browser?.close())
;
At this point, since we're not dealing with anything but the static HTML, you can dump Puppeteer and use axios or fetch to get the data more efficiently:
const axios = require("axios");
axios.get("https://store.401games.ca/collections/pokemon-singles")
.then(({data: body}) => {
const pat = /^[\t ]*var meta = ({"products":[^\n]+);$/m;
const data = JSON.parse(body.match(pat)[1]);
console.log(JSON.stringify(data, null, 2));
})
.catch(err => console.error(err))
;
Now, the data.products array contains 50 but the UI shows 26466 results. If you want more than those initial items from the static HTML's var meta, which appears to be the same on all 1000+ pages, I suggest using the API. A URL looks like https://ultimate-dot-acp-magento.appspot.com/categories_navigation?request_source=v-next&src=v-next&UUID=d3cae9c0-9d9b-4fe3-ad81-873270df14b5&uuid=d3cae9c0-9d9b-4fe3-ad81-873270df14b5&store_id=17041809&cdn_cache_key=1654217982&api_type=json&category_id=269055623355&facets_required=1&products_per_page=5000&page_num=1&with_product_attributes=true. You can see there are ids and keys that probably protect against usage by parties other than the site, but I didn't see any change other than cdn_cache_key after a few tries. I'm not sure how long a URL is valid, but while it is, you can set products_per_page=1000 for example, then move page_num=1 forward 27 times or so. This gets you all of the data while avoiding all of the difficulties of scraping from the page itself.
Here's a pessimistic approach that uses Puppeteer to get an up-to-date URL, in case a URL goes stale:
const axios = require("axios");
const puppeteer = require("puppeteer"); // ^14.1.1
let browser;
(async () => {
browser = await puppeteer.launch({headless: true});
const [page] = await browser.pages();
const url = "https://store.401games.ca/collections/pokemon-singles";
const reqP = page.waitForRequest(res =>
res.url()
.startsWith("https://ultimate-dot-acp-magento.appspot.com/categories_navigation")
);
await page.goto(url, {waitUntil: "domcontentloaded"});
const req = await reqP;
const apiUrl = req
.url()
.replace(/(?<=products_per_page=)(\d+)/, 1000);
const {data} = await axios.get(apiUrl);
console.log(JSON.stringify(data, null, 2));
})()
.catch(err => console.error(err))
.finally(() => browser?.close())
;
And tossing in the loop:
const axios = require("axios");
const fs = require("fs").promises;
const puppeteer = require("puppeteer"); // ^14.1.1
let browser;
(async () => {
browser = await puppeteer.launch({headless: true});
const [page] = await browser.pages();
const url = "https://store.401games.ca/collections/pokemon-singles";
const reqP = page.waitForRequest(res =>
res.url()
.startsWith("https://ultimate-dot-acp-magento.appspot.com/categories_navigation")
);
await page.goto(url, {waitUntil: "domcontentloaded"});
const req = await reqP;
const apiUrl = req
.url()
.replace(/(?<=products_per_page=)(\d+)/, 1000);
const items = [];
for (let i = 1;; i++) {
const pageUrl = apiUrl.replace(/(?<=page_num=)(\d+)/, i);
const response = await axios.get(pageUrl);
if (response.status !== 200 ||
items.length >= response.data.total_results) {
break;
}
items.push(...response.data.items);
}
await fs.writeFile("data.json", JSON.stringify(items));
console.log(items.slice(0, 10));
console.log(items.length);
})()
.catch(err => console.error(err))
.finally(() => browser?.close())
;
This hammers the site, pulling a ton of data in a short amount of time, so consider this script for educational purposes, or modify it to throttle your requests way back.

HTML element not selecting in Puppeteer

So I have an HTML excerpt from a webpage as follows:
<li class="PaEvOc tv5olb wbTnP gws-horizon-textlists__li-ed">
//random div/element stuff inside here
</li>
<li class ="PaEvOc tv5olb gws-horizon-textlists__li-ed">
//random div/element stuff inside here as well
</li>
Not sure how to properly copy HTML but if you look at "events near location" on Google Chrome, I'm looking at these and trying to scrape the data from them:
https://i.stack.imgur.com/fv4a4.png
To start, I'm just trying to figure out how to properly select these elements in Puppeteer:
(async () => {
const browser = await puppeteer.launch({ args: [
'--no-sandbox'
]});
const page = await browser.newPage();
page.once('load', () => console.log('Page loaded!'));
await page.goto('https://www.google.com/search?q=events+near+poughkeepsie+today&client=safari&rls=en&uact=5&ibp=htl;events&rciv=evn&sa=X&fpstate=tldetail');
console.log('Hit wait for selector')
const test = await page.waitForSelector(".PaEvOc");
console.log('finished waiting for selector');
const seeMoreEventsButton = await page.$(".PaEvOc");
console.log('seeMoreEventsButton is ' + seeMoreEventsButton);
console.log('test is ' + test);
})();
What exactly is the problem here? Any and all help much appreciated, thank you!

I suggest reading this: https://intoli.com/blog/not-possible-to-block-chrome-headless/
Basically, websites are detecting that you are scraping, but you can work around it.
Here is what I did to make your console logs print something useful
const puppeteer = require('puppeteer');
(async () => {
const preparePageForTests = async (page) => {
const userAgent = 'Mozilla/5.0 (X11; Linux x86_64)' +
'AppleWebKit/537.36 (KHTML, like Gecko) Chrome/64.0.3282.39 Safari/537.36';
await page.setUserAgent(userAgent);
}
const browser = await puppeteer.launch({ args: [
'--no-sandbox'
]});
const page = await browser.newPage();
await preparePageForTests(page);
page.once('load', () => console.log('Page loaded!'));
await page.goto('https://www.google.com/search?q=events+near+poughkeepsie+today&client=safari&rls=en&uact=5&ibp=htl;events&rciv=evn&sa=X&fpstate=tldetail');
console.log('Hit wait for selector')
const test = await page.waitForSelector(".PaEvOc");
console.log('finished waiting for selector');
const seeMoreEventsButton = await page.$(".PaEvOc");
console.log('seeMoreEventsButton is ' + seeMoreEventsButton);
console.log('test is ' + test);
})();

Exporting result from async function in separate js file, importing result in another javascript

Trying to build a small scraper. To reuse functionality I thought 'Page Object Models' would come in handy.
In main.js I require multiple small scripts, in the example below there is only one model (GooglePage).
The scripts work. But I would like to know how to pass a value from the google.js script back to the main script.
I want to use the value of the 'pageCountClean' variable in the main.js script to use in the rest of the application.
Have been searching for information about passing values and functions between scripts. For exporting values from pageconstructors, for promise await export function.
But I am lost. Do I have to use Promises?, is the current way of require/importing and exporting enough to create the relationship between the scripts?
Any pointers are welcome.
//////////// main.js
const { chromium } = require('playwright');
const { GooglePage } = require('./models/Google');
(async () => {
const browser = await chromium.launch({ headless: true, slowMo: 250 });
const context = await browser.newContext();
const GoogleUrl80 = https://www.google.nl/search?q=site%3Anu.nl;
// Cookie consent:
console.log('Cookie consent - start');
const page80 = await browser.newPage();
await page80.goto('https://google.nl');
await page80.waitForTimeout(1000);
await page80.keyboard.press('Tab');
await page80.keyboard.press('Tab');
await page80.keyboard.press('Enter');
console.log('Cookie Consent - done');
// Number of urls in google.nl (using google.js)
await page80.goto(GoogleUrl80, {waitUntil: 'networkidle'});
const googlePage80 = new GooglePage(page80);
await googlePage80.scrapeGoogle();
// Want to console.log 'pageCountClean' here.
await browser.close()
})()
//////////// Google.js
class GooglePage {
constructor(page) {
this.page = page;
}
async scrapeGoogle() {
const GoogleXpath = '//div[#id="result-stats"]';
const pageCount = await this.page.$eval(GoogleXpath, (el) => el.innerText);
const pageCountClean = pageCount.split(" ")[1];
console.log(pageCountClean);
}
}
module.exports = { GooglePage };

You can just return pageCountClean from your async function and await it in your main.js file:
in Google.js:
async scrapeGoogle() {
const GoogleXpath = '//div[#id="result-stats"]';
const pageCount = await this.page.$eval(GoogleXpath, (el) => el.innerText);
const pageCountClean = pageCount.split(" ")[1];
console.log(pageCountClean);
return pageCountClean;
}
in main.js:
const googlePage80 = new GooglePage(page80);
const result = await googlePage80.scrapeGoogle();
console.log(result);

How to call Page.navigate and trigger associated Page.loadEventFired?

I am using Chrome stable 60 (https://chromedevtools.github.io/devtools-protocol/1-2/Page/) for headless. I need to be able to do this:
Navigate to page 1
Take screenshot1
Navigate to page 2 (after page 1 is done)
Take screenshot2
However, I can't see to call Page.navigate twice because Page.loadEventFired will pick up on the latest one.
I don't want to use Canary because it's so unstable (screenshot doesn't even work right). So I think Target isn't an option (if it could be).
What is the best way to do url navigation in serial fashion like that?
I looked at https://github.com/LucianoGanga/simple-headless-chrome to see how they do it (await mainTab.goTo) but can't seem to figure out yet.

The link here https://github.com/cyrus-and/chrome-remote-interface/issues/92 gave me some idea:
const fs = require('fs');
const CDP = require('chrome-remote-interface');
function loadForScrot(url) {
return new Promise(async (fulfill, reject) => {
const tab = await CDP.New();
const client = await CDP({tab});
const {Page} = client;
Page.loadEventFired(() => {
fulfill({client, tab});
});
await Page.enable();
await Page.navigate({url});
});
}
async function process(urls) {
try {
const handlers = await Promise.all(urls.map(loadForScrot));
for (const {client, tab} of handlers) {
const {Page} = client;
await CDP.Activate({id: tab.id});
const filename = `/tmp/scrot_${tab.id}.png`;
const result = await Page.captureScreenshot();
const image = Buffer.from(result.data, 'base64');
fs.writeFileSync(filename, image);
console.log(filename);
await client.close();
}
} catch (err) {
console.error(err);
}
}
process(['http://example.com',
'http://example.com',
'http://example.com',
'http://example.com',
'http://example.com',
'http://example.com',
'http://example.com',
'http://example.com']);

Checkout the new library from google team puppeteer