我试图将util模块对象传递给puppeteerpage.evaluate
,但没有成功。我知道这个问题是在如何将所需的模块对象传递给puppeteer page.evaluate中提出的,但提供的解决方案在我的情况下不起作用。MWE:
const puppeteer = require("puppeteer");
const path = "http://books.toscrape.com/";
// scrape funs
(async () =>{
const browser = await puppeteer.launch({headless: false});
const page = await browser.newPage();
await page.goto(path, {waitUntil: "networkidle2", timeout: 0});
await page.waitFor(1000);
await page.addScriptTag({path: './node_modules/util/util.js'});
// selector with replaceable element
const buttonText = await page.evaluate(() => {
let selectorButton = "#default > div > div > div > div > section > div:nth-child(2) > ol > li:nth-child(%s) > article > div.product_price > form > button";
let buttons = [];
for(let i = 1; i < 21; i ++){
let textOut = document.querySelector(util.format(selectorButton, i)).innerText;
buttons.push(textOut);
};
return buttons;
});
// return
await browse.close();
console.log(buttonText);
})();
显示错误:
UnhandledPromiseRejectionWarning:未处理的承诺拒绝(拒绝ID:1):错误:计算失败:ReferenceError:未定义util
谢谢
在初始行中添加const util=require(“util”);
并不像如何将required module object传递给puppeteer page.evaluate中所示的那样起作用。
即使在使用browserify时,我似乎也无法将util
模块注入到puppeteer页面中。步骤:
在项目path
上,创建main.js
,如下所示:var util=require('util');
然后在终端中的path
上:browserify main.js-o bundle.js
。文件bundle.js
出现在项目path
中。
然后运行以下操作:
const puppeteer = require("puppeteer");
const path = "http://books.toscrape.com/";
// scrape funs
(async () =>{
const browser = await puppeteer.launch({headless: false});
const page = await browser.newPage();
await page.goto(path, {waitUntil: "networkidle2", timeout: 0});
await page.waitFor(1000);
await page.addScriptTag({path: "main.js"});
await page.addScriptTag({path: "bundle.js"});
// selector with replaceable element
const buttonText = await page.evaluate(() => {
let buttons = [];
let selectorButton = "#default > div > div > div > div > section > div:nth-child(2) > ol > li:nth-child(%s) > article > div.product_price > form > button";
for(let i = 1; i < 21; i ++){
let textOut = document.querySelector(util.format(selectorButton, i)).innerText;
buttons.push(textOut);
};
return buttons;
});
// return
await browse.close();
console.log(buttonText);
})();
错误:
UnhandledPromiseRejectionWarning:未处理的承诺拒绝(拒绝ID:1):错误:计算失败:TypeError:无法读取未定义的属性“Format”(位于:5:55)
您需要包含./node_modules/util/util.js
的浏览器兼容构建。您可以使用Browserify
来完成此操作,或者使用他们的在线服务Browserify wizard-util下载Browserify版本。
https://try-puppeteer.appspot.com/上的代码
const browser = await puppeteer.launch();
const page = await browser.newPage();
await page.goto("http://books.toscrape.com/", {waitUntil: "networkidle2", timeout: 0});
await page.waitFor(1000);
//Copy of https://wzrd.in/standalone/util@latest
await page.addScriptTag({url: "https://cdn.rawgit.com/brahma-dev/099d0d6d43a5d013603bcd245ee7a862/raw/b0c6bb82905b5b868c287392000dc2487c41994d/util.js"});
// selector with replaceable element
const buttonText = await page.evaluate(() => {
let buttons = [];
let selectorButton = "#default > div > div > div > div > section > div:nth-child(2) > ol > li:nth-child(%s) > article > div.product_price > form > button";
for(let i = 1; i < 21; i ++){
let textOut = document.querySelector(util.format(selectorButton, i)).innerText;
buttons.push(textOut);
};
return buttons;
});
// return
await browser.close();
console.log(buttonText);