Thursday 22 August 2024

Puppeteer: How to download File

Understanding File Downloading in Puppeteer

Puppeteer is a Node.js library that provides a high-level API to control Chrome or Chromium over the DevTools Protocol. One common use case is automating the process of downloading files. While Puppeteer does not offer a direct method for file downloads, you can achieve this by intercepting network requests or manipulating browser settings.

Step-by-Step Explanation

1. Set Up Puppeteer:

Install Puppeteer via npm:

npm install puppeteer

Import Puppeteer in your Node.js script:

const puppeteer = require('puppeteer');

2. Launch Browser and Open a New Page:

const browser = await puppeteer.launch();
   const page = await browser.newPage();

3. Set Download Behavior:

Use the page._client.send() method to specify the download path.

const downloadPath = '/path/to/downloads';
   await page._client().send('Page.setDownloadBehavior', {
       behavior: 'allow',
       downloadPath: downloadPath
   });

4. Trigger File Download:

Navigate to the page where the file is available and click the download link.

await page.goto('https://example.com/download');
   await page.click('a#downloadLink');

5. Wait for the Download to Complete:

Monitor the download folder or use a timeout to ensure the download finishes before closing the browser.

await page.waitForTimeout(5000); // Wait for 5 seconds

6. Close the Browser:

await browser.close();

Examples of Downloading Files with Puppeteer

Downloading a PDF File

To download a PDF file, you would use the same steps outlined above. If the link to the PDF is a direct URL, you can also intercept the request and save the file locally.

await page.goto('https://example.com/report.pdf');
await page.click('a#downloadPdf');

Handling Authentication Before Download

If the file is behind a login, you’ll need to automate the login process before triggering the download.

await page.goto('https://example.com/login');
await page.type('#username', 'yourUsername');
await page.type('#password', 'yourPassword');
await page.click('button#login');
await page.waitForNavigation();
await page.goto('https://example.com/download');
await page.click('a#downloadLink');

References

This article gives you a practical overview of how to download files using Puppeteer. For further details, consult the official Puppeteer documentation.

Hashtags:

javascript puppeteer

Created by:

Jorge García

Fullstack developer