我想知道如何使用 Puppeteer 的 $$eval

Question

我不能很好地使用 $$ eval。

(async() => {
    const browser = await puppeteer.launch({ executablePath: chrome ,args: [chromeArgs]});
    const page = await browser.newPage();
    await page.goto('https://www.example.com/', {waitUntil: "domcontentloaded"});
    var links = await page.evaluate(() => {
        var hreflist = [];
        var tags = document.querySelectorAll("p");
        Array.prototype.forEach.call(tags, (tag)=>{
            hreflist.push(tag.textContent);
        });
        return hreflist;
    });
    console.log(util.inspect(links, false, null));
    browser.close();
})();

我想做和上面写的源码一样的事情

(async() => {
    const browser = await puppeteer.launch({ executablePath: chrome ,args: [chromeArgs]});
    const page = await browser.newPage();
    await page.goto('https://www.example.com/', {waitUntil: "domcontentloaded"});

    var links = await page.$$eval('p', list => {
        list.map(data => {
            data.textContent
        })
    });

    console.log(util.inspect(links, false, null));
    browser.close();
})();

$$eval()的执行结果未定义

https://pptr.dev/#?product=Puppeteer&version=v1.10.0&show=api-pageevalselector-pagefunction-args 我看了官方文档。但是，我们无法确认问题。

Answer 1

您忘记了 return 值。这会起作用

var links = await page.$$eval('p', list => list.map(data => data.textContent));

我想知道如何使用 Puppeteer 的 $$eval

I would like to know how to use $$eval from Puppeteer

node.js

puppeteer