Preventing router from navigating after hash changing

问题

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' events with no way to prevent it from bubbling. The answer can be inside of JS-Signals library but it's unavailabale directly for user-created SAP components.

回答1:

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(...).

回答2:

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

来源：https://stackoverflow.com/questions/29165700/preventing-router-from-navigating-after-hash-changing