A simple JavaScript / HTML issue. (Or so I thought)

[#1]

I'm having an issue with this code from my JS file:

window.onbeforeunload = function() {
	console.log("Logging out") ;
	location.replace("http://secure.local.lan/logout.html") ;
	console.log("Logged out") ;
};

In that the page doesn't appear to be loaded. I need to force the user to load the logout.html page before they leave this secure vHost so Apache can free their login so they can log in again.

I can't help but think I am missing something here, as I see both the messages appear on the console, and the browser navigates to the link chosen (i.e. Home), but I know logout.html isn't called. Your thoughts would be appreciated.

If you need to know more, please ask.

[#2]

Mozilla suggest that it is better to use window.addEventListener() and the beforeunload event, instead of onbeforeunload.

[#3]

I have already tried that @dvorak and it 'failed' in the same way so I tried this version of it.

[#4]

OK, after a bit of reading I have a fix using this and it's a more elegant solution all round (I think).

window.addEventListener('beforeunload', (event) => {
    // Dump all of the session cookies
    document.cookie.split(";").forEach( (c) => { 
	document.cookie = c.replace(/^ +/, "").replace(/=.*/, "=;expires=" + new Date().toUTCString() + ";path=/"); 
    });
    // Send a beacon notice to the logout page
    navigator.sendBeacon("http://secure.local.lan/logout.html", null) ;
});

[#5]

Glad you sorted it