Puppeteer一次为每个文件打开chrome实例
Puppeteer一次为每个文件打开chrome实例
提问于 2018-05-28 07:29:31
我正在尝试自动化一个工作流，在这个工作流中，我有一个目录中的文件列表，并将它们放在一个数组中。然后，对于数组中的每个文件，我都会调用一个Chrome自动化函数。
const path = require('path');
const chalk = require('chalk');
const puppeteer = require('puppeteer');
module.exports = {
generateOutput : async(fileName, url = "https://example.com/") => {
const filePath = path.join(process.cwd(), fileName);
const outputFilePath = path.join(process.cwd(), "OutputFiles");
try{
const browser = await puppeteer.launch({headless: false});
process.setMaxListeners(0);
const page = await browser.newPage();
await page._client.send('Page.setDownloadBehavior', {behavior: 'allow', downloadPath: outputFilePath});
page.on('dialog', async dialog => {
console.log(chalk.magenta("Error Occured: " + dialog.message()));
await dialog.dismiss();
await browser.close();
});
await page.goto(url, {waitUntil: 'networkidle2'});
await page.click('#ui-id-9');
await page.click('#ui-id-18');
await page
.waitForSelector('#ui-id-9')
.then(() => console.log(chalk.magenta("Uploader module visible... Uploading the files") ));
const input = await page.$('#upload-file');
await input.uploadFile(filePath);
await page.waitFor(10000);
await page.click("#up-file");
await page.waitFor(50000);
await page
.waitForSelector('#ui-id-18')
.then(() => console.log(chalk.magenta("Downloader module visible... Downloading the files") ));
await page.click("#download-td");
await page.waitFor(100000);
await browser.close();
}
catch(e){
console.log(chalk.red(fileName + ' has failed in conversion.'));
}
}
};这会同时创建一个chrome实例(假设100个文件为100个)。有没有办法限制异步进程。我没有太多经验。所以我不能搜索正确的词条。
回答 1
Stack Overflow用户
回答已采纳
发布于 2018-05-28 07:35:42
一种解决方案是逐个访问每个文件的urls。
const path = require('path');
const chalk = require('chalk');
const puppeteer = require('puppeteer');
module.exports = {
start: async() => {
const browser = await puppeteer.launch({headless: false});
const page = await browser.newPage();
// for all the files in array call it one by one
for (i = 0; i < files.length; i++) {
await module.exports.generateOutput(page, fileName);
}
await browser.close();
},
generateOutput : async(page, fileName, url = "https://example.xm/b") => {
const filePath = path.join(process.cwd(), fileName);
const outputFilePath = path.join(process.cwd(), "OutputFiles");
try{
process.setMaxListeners(0);
await page._client.send('Page.setDownloadBehavior', {behavior: 'allow', downloadPath: outputFilePath});
page.on('dialog', async dialog => {
console.log(chalk.magenta("Error Occured: " + dialog.message()));
await dialog.dismiss();
await browser.close();
});
await page.goto(coloradoUrl, {waitUntil: 'networkidle2'});
await page.click('#ui-id-9');
await page.click('#ui-id-18');
await page
.waitForSelector('#ui-id-9')
.then(() => console.log(chalk.magenta("Uploader module visible... Uploading the files") ));
const input = await page.$('#upload-file');
await input.uploadFile(filePath);
await page.waitFor(10000);
await page.click("#up-file");
await page.waitFor(50000);
await page
.waitForSelector('#ui-id-18')
.then(() => console.log(chalk.magenta("Downloader module visible... Downloading the files") ));
await page.click("#download-td");
await page.waitFor(100000);
}
catch(e){
console.log(chalk.red(fileName + ' has failed in conversion.'));
}
}
};的另一个功能是为每个文件打开新的标签，并在文件完成后关闭它。但这可以一次打开100个标签。您可以添加上限，例如，一次最多打开10个选项卡等。以下代码使用 delay 函数在打开新选项卡之前主动等待选项卡数小于10
const path = require('path');
const chalk = require('chalk');
const puppeteer = require('puppeteer');
module.exports = {
delay: async (milisecs) => {
return new Promise(function(resolve, reject) {
setTimeout(resolve, milisecs);
})
},
start: async() => {
const browser = await puppeteer.launch({headless: false});
// for all the files in array call it one by one
for (i = 0; i < files.length; i++) {
pages = await browser.pages();
/*
* if number of tabs is less than 10, skips while. Else
* waits till number of open tabs become less than 10
*/
while (pages.length == 10) {
pages = await browser.pages();
await module.exports.delay(3000);
}
// then open a new tab
const page = await browser.newPage();
module.exports.generateOutput(page, fileName);
}
await browser.close();
},
generateOutput : async(page, fileName, url = "https://example.xm/b") => {
const filePath = path.join(process.cwd(), fileName);
const outputFilePath = path.join(process.cwd(), "OutputFiles");
try{
process.setMaxListeners(0);
await page._client.send('Page.setDownloadBehavior', {behavior: 'allow', downloadPath: outputFilePath});
page.on('dialog', async dialog => {
console.log(chalk.magenta("Error Occured: " + dialog.message()));
await dialog.dismiss();
await browser.close();
});
await page.goto(url, {waitUntil: 'networkidle2'});
await page.click('#ui-id-9');
await page.click('#ui-id-18');
await page
.waitForSelector('#ui-id-9')
.then(() => console.log(chalk.magenta("Uploader module visible... Uploading the files") ));
const input = await page.$('#upload-file');
await input.uploadFile(filePath);
await page.waitFor(10000);
await page.click("#up-file");
await page.waitFor(50000);
await page
.waitForSelector('#ui-id-18')
.then(() => console.log(chalk.magenta("Downloader module visible... Downloading the files") ));
await page.click("#download-td");
await page.waitFor(100000);
await page.close()
}
catch(e){
console.log(chalk.red(fileName + ' has failed in conversion.'));
}
}
};我已经修改了你的代码来传达这个概念。当然，它不会运行，直到您将files替换为您自己的变量等
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原文链接：
https://stackoverflow.com/questions/50557418
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