React Navigation on tab change

Question

Without using Redux, how do I detect a tab change with a react navigation tab navigator?

I know I need to somehow use onNavigationStateChange but I can\'t figure out

Answer 1

export default () =>  { this.nav = ref; }}
    onNavigationStateChange={(prevState, currentState) => {
       const getCurrentRouteName = (navigationState) => {
         if (!navigationState) return null;
         const route = navigationState.routes[navigationState.index];
         if (route.routes) return getCurrentRouteName(route);
         return route.routeName;
       };
    global.currentRoute = getCurrentRouteName(currentState);
  }}
/>;

If you don't want to use redux, this is how you can store global information about the current route, so you can both detect a tab change and also tell which tab is now active.