Capturing a particular response in Puppeteer: What's the best approach?

Other Questions Puppeteer
1

Hey folks, I’ve been playing around with Puppeteer, the headless Chrome API for Node.js. I’m trying to figure out how to catch a specific response and do something based on it. I’ve looked into the requestfinish and response events, but they give me everything that’s happened on the page. That’s not quite what I’m after.

I’m aiming to zero in on just one response. Maybe I want to check if a certain API call was successful or grab some data from a particular request. Has anyone cracked this puzzle before? What’s the best way to set up a listener for a single response in Puppeteer?

Any tips or code snippets would be super helpful. I’m kinda stuck and could use some guidance from the community. Thanks in advance!

// Example of what I'm trying to do
browser.on('someEvent', async (response) => {
  if (response.url() === 'https://api.example.com/data') {
    const data = await response.json();
    console.log('Got the data I wanted:', data);
    // Do something with the data
  }
});

Is there a way to set this up in Puppeteer? Let me know if you need more info about what I’m trying to achieve!

2

hey mate, i’ve used puppeteer for similar stuff. try this:

page.on('response', async (response) => {
  if (response.url().includes('api.example.com')) {
    const data = await response.json();
    console.log('gotcha:', data);
    // do your thing here
  }
});

it’ll catch all responses from that domain. adjust the url check as needed. good luck!

3

I’ve found that using the ‘setRequestInterception’ method in combination with ‘request.continue()’ works well for capturing specific responses. Here’s a snippet that might help:

await page.setRequestInterception(true);
page.on('request', request => {
  if (request.url() === 'https://api.example.com/data') {
    request.continue({
      onResponse: response => {
        console.log('Intercepted response:', response);
        // Process your response here
      }
    });
  } else {
    request.continue();
  }
});

This approach allows you to intercept and modify requests before they’re sent, giving you fine-grained control over the process. It’s particularly useful when you need to manipulate headers or payload data. Just remember to handle all requests, even those you’re not interested in, to avoid hanging the page load.

4

I’ve tackled this exact problem before, and I found that using page.on(‘response’) is the most reliable method. Here’s how I’ve implemented it:

await page.on('response', async (response) => {
  if (response.url() === 'https://api.example.com/data') {
    const data = await response.json();
    console.log('Got the data:', data);
    // Process your data here
  }
});

This approach allows you to listen for all responses, but only act on the one you’re interested in. Make sure to set this up before navigating to your page or making the request you want to intercept.

One caveat: if the response isn’t JSON, you’ll need to use a different method to parse it, like response.text() for plain text.

Also, remember to remove the listener when you’re done to avoid memory leaks, especially if you’re creating multiple pages:

page.removeListener('response', yourListenerFunction);

Hope this helps you move forward with your Puppeteer project!