ACS logout - add global logout function to follow DRY principle

I want to add a logout button on the navbar rightNavButton. The following code creates and activates the button, but for only one page.

var loggedIn = Ti.App.Properties.getBool('app:isLoggedIn');
 
    var logOutButton = Ti.UI.createButton({
        title : 'Log Out'
    });
 
    $.homeView.setRightNavButton(logOutButton);
 
    logOutButton.addEventListener('click', function(e) {
 
        Cloud.Users.logout(function(e) {
            if (e.success) {
                alert('Success: Logged out');
                Ti.App.Properties.setBool('app:isLoggedIn', false);
            } else {
                Ti.API.log('Error:\n' + ((e.error && e.message) || JSON.stringify(e)));
            }
        });
 
    });

I've looked at setting this code as a global function Alloy.Globals.logOut, but not sure how to pass in the calling view controller as a parameter. With this example, $.homeView is the calling controller.

My questions are: 1) Is there an easier/better way to do this so that I don't have to repeat the same code on each page? 2) Is it safe to make a function like this global?

As always, if you need more detail, please ask. And thank you for your time.