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Retrieving DOM node text with Puppeteer and headless Chrome

I am trying to use the headless Chrome and Puppeteer to run our Javascript tests, but I cannot extract the results from the page. Based on this answer , it looks like I should use page.evaluate(). There is an example in this section that looks the way I need it.

const bodyHandle = await page.$('body');
const html = await page.evaluate(body => body.innerHTML, bodyHandle);
await bodyHandle.dispose();

As a complete example, I tried converting it to a script that would extract my name from my user profile in Stack Overflow. Our project uses Node 6, so I used expressions awaitto use .then().

const puppeteer = require('puppeteer');

puppeteer.launch().then(function(browser) {
    browser.newPage().then(function(page) {
        page.goto('https://stackoverflow.com/users/4794').then(function() {
            page.$('h2.user-card-name').then(function(heading_handle) {
                page.evaluate(function(heading) {
                    return heading.innerText;
                }, heading_handle).then(function(result) {
                    console.info(result);
                    browser.close();
                }, function(error) {
                    console.error(error);
                    browser.close();
                });
            });
        });
    });
});

When I ran this, I get this error:

$ node get_user.js 
TypeError: Converting circular structure to JSON
    at Object.stringify (native)
    at args.map.x (/mnt/data/don/git/Kive/node_modules/puppeteer/node6/helper.js:30:43)
    at Array.map (native)
    at Function.evaluationString (/mnt/data/don/git/Kive/node_modules/puppeteer/node6/helper.js:30:29)
    at Frame.<anonymous> (/mnt/data/don/git/Kive/node_modules/puppeteer/node6/FrameManager.js:376:31)
    at next (native)
    at step (/mnt/data/don/git/Kive/node_modules/puppeteer/node6/FrameManager.js:355:24)
    at Promise (/mnt/data/don/git/Kive/node_modules/puppeteer/node6/FrameManager.js:373:12)
    at fn (/mnt/data/don/git/Kive/node_modules/puppeteer/node6/FrameManager.js:351:10)
    at Frame._rawEvaluate (/mnt/data/don/git/Kive/node_modules/puppeteer/node6/FrameManager.js:375:3)

, page.evaluate(). , . , Node 6? DOM node?

+6
2

, . - , : page.$eval(). , : page.$() page.evaluate(). , :

const puppeteer = require('puppeteer');

puppeteer.launch().then(function(browser) {
    browser.newPage().then(function(page) {
        page.goto('https://stackoverflow.com/users/4794').then(function() {
            page.$eval('h2.user-card-name', function(heading) {
                return heading.innerText;
            }).then(function(result) {
                console.info(result);
                browser.close();
            });
        });
    });
});

:

$ node get_user.js 
Don Kirkby top 2% overall

- , , , , . , , , . jQuery , , :

const puppeteer = require('puppeteer');

puppeteer.launch().then(function(browser) {
    browser.newPage().then(function(page) {
        page.goto('https://stackoverflow.com/users/4794').then(function() {
            page.evaluate("$('h2.user-card-name').text()").then(function(result) {
                console.info(result);
                browser.close();
            });
        });
    });
});

:

$ node get_user.js 

                            Don Kirkby

                                top 2% overall

script, , :

const puppeteer = require('puppeteer');

puppeteer.launch().then(function(browser) {
    browser.newPage().then(function(page) {
        page.goto('https://stackoverflow.com/users/4794').then(function() {
            page.evaluate(function() {
                return $('h2.user-card-name').text();
            }).then(function(result) {
                console.info(result);
                browser.close();
            });
        });
    });
});

. , , .

+6

await/async $eval, :

await page.goto('https://stackoverflow.com/users/4794')
const nameElement = await context.page.$eval('h2.user-card-name', el => el.text())
console.log(nameElement)
+1

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