Node.js Puppeteer: How to receive XHR response of iframe (with JS web worker)

Question

I have a page which communicates to a server every 10 seconds via XHR inside an iframe. I would like to monitor the responses (text/plain UTF-8).

Opposite to the DevTools Network list, it seems Puppeteer does not "detect" XHR responses from inside iframes, with it's normal page procedure:

page.on('response', async (response) => {}

When the ID of the iframe is known, is there any way to receive the XHR responses of the iframe? (with a JS web worker doing the XHR requests)

Answer 1

I have written this example which showcases that requests are indeed captured from inner frames of your page. You have to be careful, requests that fail won't actually trigger page.on('response') handler but will trigger page.on('requestfailed').

Also make sure to call await page.setRequestInterception(true) before adding any request related handlers to your page!

Here is a working example: (it will only trigger requestFailed due to cross origin restrictions.)

var puppeteer = require('puppeteer')

function simulateRequest() {

    function doXmlHTTPRequest() {
        function reqListener() {
            console.log('xml done.')
            console.log(this.responseText);
        }

        var oReq = new XMLHttpRequest();
        oReq.addEventListener("load", reqListener);
        oReq.open("GET", "https://www.google.com");
        oReq.send();
    }


    setInterval(doXmlHTTPRequest, 2 * 1000)

}

// Easiest way to get an Iframe is by its name.
const findFrame = (frames, name) => {
    return frames.find(f => f.name() === name)
}

const main = async() => {
    const browser = await puppeteer.launch({ headless: false });
    const page = await browser.newPage()

    // have a page with only an iframe.
    const pageContent = '<iframe id="myFrame" name="frameName">'
    await page.setContent(pageContent)

    // important call!
    await page.setRequestInterception(true)

    page.on('response', async(res) => {
        console.log('Page response received..', )
    })

    page.on('requestfailed', () => {
        console.log('requestfailed recieved')
    })

    page.on('request', async(res) => {
        console.log('page request received..', )

        // make sure to continue request.
        res.continue()
    })

    // find the iframe!
    const targetFrame = findFrame(page.frames(), 'frameName')

    // set some test content..
    await targetFrame.setContent('<h1>hello</h1>')


    // add a script to iframe which simulates requests!
    await targetFrame.addScriptTag({

        // execute the function immediatly..
        content: `(${simulateRequest.toString()})()`
    })

}

main()