Earlier in the chapter, you were introduced to the <ActivityIndicator> component. In this section, you'll learn how it can be used when navigating an application that loads data. For example, the user navigates from page (scene) one to page two. However, page two needs to fetch data from the API to display for the user. So while this network call is happening, it makes more sense to display a progress indicator instead of a screen devoid of useful information.
Doing this is actually kind of tricky, because we have to make sure that the data required by the screen is fetched from the API each time the user navigates to the screen. So, we have two goals in mind here:
Have the
Navigatorcomponent automatically fetch API data for the scene that's about to be rendered.Use the promise that's returned by the API call as a means to display the spinner and hide it once the promise has resolved.
Since our scene components probably don't care about whether or not a spinner...