Detecting page status in Puppeteer: How to tell if a page remains open?

Other Questions Puppeteer
1

I’m working on a Puppeteer script where I perform operations on a webpage, but occasionally other async tasks might close it unexpectedly. I’m using an async loop to carry out these actions, and I need to know when the page is no longer active. Below is a revised code example:

const monitorWebpage = async (page) => {
  while (checkPageActivity(page)) {
    await page.evaluate(() => {
      // Perform some action on the page
    });
    await pause(1000); // Wait before repeating
  }
};

const checkPageActivity = (page) => {
  // How can I determine if the page is still open?
};

Any advice on implementing the checkPageActivity function or a better approach would be appreciated!

2

From my experience with Puppeteer, there’s another reliable method to check if a page is still open. You can use the page.isClosed() function, which returns a boolean value. Here’s how you could implement it:

const monitorWebpage = async (page) => {
  while (!page.isClosed()) {
    try {
      await page.evaluate(() => {
        // Perform some action on the page
      });
      await page.waitForTimeout(1000);
    } catch (error) {
      console.error('An error occurred:', error);
      break;
    }
  }
  console.log('Page is no longer active');
};

This approach is straightforward and doesn’t rely on error catching. It’s also more explicit about the page’s state, which can be helpful for debugging. Remember to handle any potential errors within the loop to prevent the script from crashing unexpectedly.

3

I’ve faced similar issues with Puppeteer, and here’s what worked for me. Instead of using a separate function to check page activity, you can wrap your main operations in a try-catch block. Puppeteer throws an error when trying to interact with a closed page.

Here’s how I’d modify your code:

const monitorWebpage = async (page) => {
  try {
    while (true) {
      await page.evaluate(() => {
        // Perform some action on the page
      });
      await page.waitForTimeout(1000); // More reliable than custom pause
    }
  } catch (error) {
    if (error.message.includes('Protocol error')) {
      console.log('Page is closed');
    } else {
      throw error; // Re-throw if it's a different error
    }
  }
};

This approach is more robust and doesn’t require a separate check. It automatically detects when the page is closed and handles it gracefully. Hope this helps!

4

hey mate, i’ve been messing with puppeteer too and found a neat trick. you can use page.target().isAttached() to check if the page is still connected. like this:

const checkPageActivity = (page) => {
return page.target().isAttached();
};

works like a charm for me. give it a shot!