Logout with Javascript Event when closing the window

Question

Situation

I have a system in which I need the user to be dropped when closing the browser.

Code

in this way I was able to catch the closing of the browser, or better to say the 'exit' of the page for a new ( or not in case of browser closure ). But it is blocking me in the confirmation.

var myEvent = window.attachEvent || window.addEventListener;
var chkevent = window.attachEvent ? 'onbeforeunload' : 'beforeunload'; /// make IE7, IE8 compatable

    myEvent(chkevent, function(e) { // For >=IE7, Chrome, Firefox
      var confirm = window.confirm('Deseja fazer logout?');
      if(confirm){
        logout();
      }
    });

    function logout (){
      console.log('Logout');
    }

Error

Blocked confirm('Do you want to log out?') During beforeunload

Someone would have another way to effect this functionality?

Answer 1

The window.confirm will not work because the structure of onbeforeunload already owns a return to the confirmation screen, I believe that the correct would be this:

window.onbeforeunload = function() {
    return "Gostaria mesmo de sair?";
};

However note that it will not be possible to trigger events if you click on "Ok", because the window will already be closed, by the time the window or tab closes its instance is destroyed and for this reason it is no longer possible to send events, because it no longer "exists".

So if you want to create an event that will depress the user from your system (assuming you are using php, .net, jsf, etc) it will be necessary to create a "timer" to expire the user, a good time would be "2 mintuos", note that the Google Analytics uses a technique similar to the one I mentioned.

In the case of the author, you are using Ruby On Rails, can try this (as per Soen):

Authlogic can do this by default. I suggest you migrate your authentication system (it may take some time depending on how much your system is customized).

There is this example too http://github.com/binarylogic/authlogic_example