Welcome to OGeek Q&A Community for programmer and developer-Open, Learning and Share
Welcome To Ask or Share your Answers For Others

Categories

0 votes
351 views
in Technique[技术] by (71.8m points)

node.js - Nodejs Puppeteer Wait to finish all code from loop

I'm using puppeteer to scrap a webpage. In this webpage, i input some text and click the submit button. Once clicked, the page will return a table with results. I want to get these table results when matches 'somevar'. The problem is: The for is not completing all functions before looping. Instead of filling the input and get the results first, it already goes to the next loop and fill the input again, resulting in something like: 'test1test2'

How to make the for execute all functions inside before looping?

callPup();

async function callPup(){

'use strict';

const puppeteer = require('puppeteer');

const textos = ['test1','test2'];

(async() => {
    const browser = await puppeteer.launch({headless: false});
    const page = await browser.newPage();

    await page.goto('http://localhost/teste.html');     

    await page.waitForSelector('#input1').then(funcOk());


    async function funcOk(){            
        for (let i = 0; i < textos.length; i++) {                       

            await page.type('#input1', textos[i]);

            await page.keyboard.press('Enter');                 

            /*get table results*/
            const data = page.evaluate(() => {
                const tds = Array.from(document.querySelectorAll('table tr td a'))
                return tds.map(a => {
                    var txt = a.innerHTML;
                    return txt.replace(/<a [^>]+>[^<]*</a>/g, '').trim();
                });
            });
            /*get table results*/

            /*get only valid results*/
            let j = 0;
            for (let z = 0; z < data.length; z++) {
                if(data[z] == someVar[i].num.toString()){
                    j = j + 1;          
                }
                if(j <= 14){
                    console.log(data[z]);
                    j = j + 1;
                }
            }
            /*get only valid results*/
        }           
    }

})();   

}

See Question&Answers more detail:os

与恶龙缠斗过久,自身亦成为恶龙;凝视深渊过久,深渊将回以凝视…
Welcome To Ask or Share your Answers For Others

1 Reply

0 votes
by (71.8m points)

You can run a loop synchronously in series using Promise, it would be easier to just use a library like async. Try using eachSeries https://caolan.github.io/async/docs.html#eachSeries

    function funcOk(){            
        async.eachSeries(textos, async (text) => {                     

            await page.type('#input1', text);

            await page.keyboard.press('Enter');                 

            /*get table results*/
            const data = page.evaluate(() => {
                const tds = Array.from(document.querySelectorAll('table tr td a'))
                return tds.map(a => {
                    var txt = a.innerHTML;
                    return txt.replace(/<a [^>]+>[^<]*</a>/g, '').trim();
                });
            });
            /*get table results*/

            /*get only valid results*/
            let j = 0;
            for (let z = 0; z < data.length; z++) {
                if(data[z] == someVar[i].num.toString()){
                    j = j + 1;          
                }
                if(j <= 14){
                    console.log(data[z]);
                    j = j + 1;
                }
            }
            /*get only valid results*/

            return Promise.resolve()
        })
    }

与恶龙缠斗过久,自身亦成为恶龙;凝视深渊过久,深渊将回以凝视…
OGeek|极客中国-欢迎来到极客的世界,一个免费开放的程序员编程交流平台!开放,进步,分享!让技术改变生活,让极客改变未来! Welcome to OGeek Q&A Community for programmer and developer-Open, Learning and Share
Click Here to Ask a Question

...