我需要在浏览器关闭时弹出确认窗口。我正在使用onbeforeunload事件，但无法在Firefox中使用，并且还希望限制页面刷新时的弹出窗口

Question

I need a confirmation pop up on browser close. I amm using onbeforeunload event but not working in Firefox also the pop up comes whenever the page refreshed which I want to restrict.

window.onbeforeunload = DetectBrowserExit;

function DetectBrowserExit() {
return 'Are you sure to exit';`enter code here`
}

Answer 1

Not all browsers support this feature and with time browsers minimized their support (for example removed custom text support). Reason is that it is used by spam like websites that prevent you from navigating out.

you can see full details here:

https://developer.mozilla.org/en-US/docs/Web/API/WindowEventHandlers/onbeforeunload

Checkout also the Browser compatibility section in that page. I would definitely suggest NOT to rely on that event and come up with alternatives that fit your website more.

specifically about firefox, see this explanation from the link I shared above:

Note also that various mobile browsers ignore the result of the event (that is, they do not ask the user for confirmation). Firefox has a hidden preference in about:config to do the same. In essence this means the user always confirms that the document may be unloaded.