问Nodejs puppeteer在node js控制台输出多条并行进度行
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Stack Overflow用户

提问于 2018-12-08 20:41:03

回答 1查看 960关注 0票数 2

我创建了一个简单的程序自动上传文件到一个网站上。我正在使用puppeteer进行无头浏览、登录和上传。我正在通过将突变观察者注入dom并将其登录到控制台来监听上传栏的变化。

const puppeteer = require('puppeteer');
var path = require('path');
var glob = require("glob");

async function upload(file_path, file_index) {
    // launch puppeteer
    const browser = await puppeteer.launch({
        headless: true,
    });
    const page = await browser.newPage();

    // some code here to navigate then upload to the website
    /*****************************************************

    UPLOADING CODE HERE...
    1. UPLOAD FILE
    2. THEN LOG THE PROGRESS TO CONSOLE
    there is some code here but i will not include it here to make it short

    ******************************************************/

    // everytime a change has been log in console
    await page.on('console', async (response) => {

        //fetch the progress percentage
        var percent = await page.$eval('#progressbar', el => el.innerText);

        // log the progress
        console.log('File ' + file_index + ' Percent uploaded: ' + percent)

    });

}

// lets say there are 5 files in the server
glob("files/*.mp4", function(er, files) {

    files.forEach(function(file, video_index) {
        upload(file, video_index);
    });

});

上传工作正常，但问题是将进度输出到控制台时。我的程序一直在写换行符，而不是创建并行的进度行。假设我将异步上传5个文件。程序输出的内容如下：