Saving Progress

A common use-case is to store the users progress on a particular Track somewhere so that when they leave and come back, they can pick up right where they left off. To do this you need to listen for progress updates and then store the progress somewhere. There are two high level ways of getting this done.

Naive Approach

One approach could be to use the progress events/updates that the useProgress hook provides. This isn't a very good idea and here's why:

Users can listen to audio both "in-App" and "Remotely". In-App would be defined as playback while the user has the app opened on screen. However, whenever audio is being played in the background/remotely. For example: playback on the lockscreen, carplay, etc. In these situations the UI is not mounted, meaning the useProgress hook, or really any event listeners that are registered inside of your App UI tree (anything called as a result of AppRegistry.registerComponent(appName, () => App); in your index.js file) WILL NOT EXECUTE.

In a nutshell, if you do this, you're progress will not update when the user is playing back in Remote contexts and therefore your app will seem buggy.

Recommended Approach

The correct way to handle this is to track progress in the Playback Service, based on the Event.PlaybackProgressUpdated event. These events fire all the time, including when your app is playing back remotely.