Can we transmit information from web browser to Puppeteer?

Other Questions Puppeteer
1

Hey everyone! I’m trying to transition from PhantomJS to Puppeteer for server-side rendering. Previously, I used window.callPhantom() to communicate from the browser to PhantomJS either when the page was complete or when there was an error. Now, I’d like to know if there’s a way to do this with Puppeteer.

I need to achieve the following:

  1. Wait until all AJAX requests on the client side are finished.
  2. Notify Puppeteer that the page is ready to be rendered.
  3. Handle scenarios where the page fails to load correctly.

Is there an equivalent method in Puppeteer to PhantomJS’s callPhantom, or any alternative way to send such data from the browser to Puppeteer?

Below is a sample code snippet to illustrate what I mean:

// Client-side
function sendStatusToPuppeteer(status) {
  // Code to send the status to Puppeteer
}

// When the page is fully loaded
sendStatusToPuppeteer('ready');

// In case of an error
sendStatusToPuppeteer('error');

// Server-side (Puppeteer)
// Code to handle the received status

Any suggestions on how to implement this in Puppeteer would be greatly appreciated!

2

I’ve dealt with similar challenges when migrating from PhantomJS to Puppeteer. One approach that worked well for me was using a combination of page.exposeFunction() and custom events. I exposed a function to the browser context that logged incoming messages from the client. In the browser, I set up an event listener for a custom event and, when needed, dispatched this event with the relevant status detail (like ‘ready’ or ‘error’). This method provided me with flexible communication between the browser and Puppeteer, especially useful for managing AJAX completions and error scenarios. It might be worth giving it a try in your setup.

3

To transmit information from the browser to Puppeteer, you can use the page.exposeFunction() method together with page.evaluate(). This technique sets up a communication bridge between the browser and the Node.js context running Puppeteer.

For example, you can expose a function that handles status messages:

await page.exposeFunction('sendStatusToPuppeteer', (status) => {
    if (status === 'ready') {
        console.log('Page is ready for rendering');
        // Perform further actions
    } else if (status === 'error') {
        console.error('Page encountered an error');
        // Handle error scenario
    }
});

Then, on the client-side, you can evaluate code that calls this function based on your page’s conditions:

await page.evaluate(() => {
    // Client-side code
    function checkPageStatus() {
        if (/* All AJAX requests are complete */) {
            window.sendStatusToPuppeteer('ready');
        } else if (/* Error condition */) {
            window.sendStatusToPuppeteer('error');
        }
    }
    // Call checkPageStatus when appropriate
});

This approach offers a clear way to notify Puppeteer of the page state and handle different scenarios effectively.

4

hey sophia, puppeteer’s got u covered! u can use page.exposeFunction() to make a function available in the browser. then use page.evaluate() to call it. something like:

await page.exposeFunction('sendStatus', (status) => console.log(status));
await page.evaluate(() => sendStatus('ready'));

hope this helps!