Preventing router from navigating

Question

I need to prevent router to be navigated to another page (which is done by changing the hash) if some changes are made. Tried with HashChanger but it just fires \'hashChange\' e

Answer 1

Instead of stopping the router entirely, navigation can be prevented by event.preventDefault() within the navigate event handler.

<App xmlns="sap.m" navigate=".onNavigate">

onNavigate: function(event) {
  if (/* pending changes? */) {
    event.preventDefault();
    const { isBack, isBackToPage, isBackToTop } = event.getParameters();
    if (isBack || isBackToPage || isBackToTop) {
      window.history.go(1);
    } else {
      window.history.go(-1);
    }
    this.informUser("There are still pending changes.");
  }
}

Demo: https://embed.plnkr.co/wp6yes

Answer 2

There is a stop function on the router https://sapui5.hana.ondemand.com/#/api/sap.ui.core.routing.Router/methods/stop

if you call it, the router will stop listening to hashchanges.

There is also function isStopped(). To (re-)activate the router, call initialize(...).