如果用户点击停留在页面上，则重定向的Javascript警报

Question

I have searched everywhere and I cannot find the exact solution that I am looking for. I need a javascript code that when the user tries to exit the page, an alert box pops up with the "stay on page" or "leave page" options. If the user stays, it redirects them to another page and if they choose leave it leaves. Something similar to exit splash. I know this is poor practice but it is what the clients wants. Any help will be greatly appreciated. Thanks in advance for your help.

Answer 1

This is hacky but will do the job

var triedToLeave = false;
function onBeforeUnload(){
    triedToLeave = true;
    return "you can put your own message here";
}
setInterval( function (){
     if( triedToLeave ){
         window.removeEventListener( "beforeunload", onBeforeUnload, false );
         document.location.href = "http://stackoverflow.com/";
     }
}, 2000 );
window.addEventListener( "beforeunload", onBeforeUnload, false);

EDIT fixed function

Answer 2

This should accomplish the final result you want, though it technically directs the user to the splash page before they make their decision.

var notScriptLeaving = true;
window.onbeforeunload = function() {
    if (notScriptLeaving) {
        notScriptLeaving = false;
        window.location = 'http://www.example.com/'; //Splash page url goes here
        return "Are you sure you want to navigate away?";
    }
}