I want to intercept all route changes with Sammy to first check if there is a pending action. I have done this using the `sammy.before` API and I return false to cancel the route. This keeps the user on the 'page' but it still changes the hash in the browsers address bar and adds the route to the browsers' history. If I cancel the route, I dont want it in the address bar nor history, but instead I expect the address to stay the same. 

Currently, to get around this I can either call window.history.back (yuk) to go back to the original spot in the history or sammy.redirect. Both of which are less than ideal.

Is there a way to make sammy truly cancel the route so it stays on the current route/page, leaves the address bar as is, and does not add to the history?

If not, is there another routing library that will do this?

```
sammy.before(/.*/, function () {
    // Can cancel the route if this returns false
    var response = routeMediator.canLeave();

if (!isRedirecting && !response.val) {
    isRedirecting = true;
    // Keep hash url the same in address bar
    window.history.back();
    //this.redirect('#/SpecificPreviousPage'); 
}
else {
    isRedirecting = false;
}
return response.val;
});

```