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I am trying out Puppeteer. This is a sample code that you can run on: https://try-puppeteer.appspot.com/
The problem is this code is returning an array of empty objects:
[{},{},{},{},{},{},{},{},{},{},{},{},{},{},{},{},{},{},{},{},{},{},{},{},{},{},{},{},{},{},{},{},{},{},{},{},{},{},{},{},{},{},{},{},{},{},{},{},{},{},{},{},{},{},{},{},{}]
Am I making a mistake?
const browser = await puppeteer.launch(); const page = await browser.newPage(); await page.goto('https://reddit.com/'); let list = await page.evaluate(() => { return Promise.resolve(Array.from(document.querySelectorAll('.title'))); }); console.log(JSON.stringify(list)) await browser.close(); 
325
The Document method querySelectorAll() returns a static (not live) NodeList representing a list of the document's elements that match the specified group of selectors.
Evaluates a function in the page's context and returns the result. If the function passed to page. evaluteHandle returns a Promise, the function will wait for the promise to resolve and return its value.
The querySelectorAll method returns an array-like object called a node list. These data structures are referred to as “Array-like”, because they appear as an array, but can not be used with array methods like map and forEach .
The difference between these two is that querySelector returns a single element matching its selection criteria. querySelectorAll, on the other hand, returns all elements matching the search criteria in an iterable list.
The values returned from evaluate function should be json serializeable. https://github.com/GoogleChrome/puppeteer/issues/303#issuecomment-322919968
the solution is to extract the href values from the elements and return it.
await this.page.evaluate((sel) => { let elements = Array.from(document.querySelectorAll(sel)); let links = elements.map(element => { return element.href }) return links; }, sel); If you love us? You can donate to us via Paypal or buy me a coffee so we can maintain and grow! Thank you!
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