disable "leave page" pop-up in pavlovia

[isaosenberger]

Hi all,

I am using Pavlovia to run my JsPsych experiment. Everything is working, except for a pop-up window that I get whenever I leave my experiment page. I'd would be great if someone can help me disable that pop-up :)

For some context: in my experiment the participant gets the option to redirect to a different website with a button click. Whenever I (or the participants) press that button, I get this pop-up window asking me whether I really want to leave the experiment page:

I'd like to disable that pop-up window, but I am unsure how to do that. I didn't find a way to disable the pop-up on Pavlovia, therefore I assume that I have to do that in my code.

I did some searching and think that I found the source of my "problem" in the pavlovia plug-in, here:

// warn the user when they attempt to close the tab or browser:
const _beforeunloadCallback = (event) =>
{
// preventDefault should ensure that the user gets prompted:
event.preventDefault();
// Chrome requires returnValue to be set:
event.returnValue = '';
};
window.addEventListener('beforeunload', _beforeunloadCallback);

and here:

/**
* The callback for the beforeunload event, which is triggered when the participant
* tries to leave the experiment by closing the tab or browser.
*
* @type {null}
* @private
*/
PavloviaPlugin._beforeunloadCallback = null;

but I am unsure how to proceed from here. Any help is much appreciated!
I am using jspsych 7.2.3, and the pavlovia plug in is 2022.1.1

Thanks a lot!

Best,
Lisa

[jodeleeuw]

Hi @isaosenberger,

Can you modify the code to the pavlovia plugin? If so, removing the window.addEventListener(...) might do the trick.

If you can't easily modify the plugin code, then adding this statement might do the trick:

window.addEventListener('beforeunload', function(event) {
    event.stopImmediatePropagation();
}, true);

This will add a new event listener to the beforeunload event, and it will stop the event from propogating so the other event listener for pavlovia will not be called. The downside is this will stop all functions tied to beforeunload, so you have to ensure that there are no other functions that are triggered by that event.

[isaosenberger]

Hi @jodeleeuw,

thanks for your help!

I commented out everything that has to do with the beforeunload event listener in the pavlovia plugin, and it works like a charm :)

Best,
Lisa