I have a settings page where users can save some config variables, such as a Username. The user can also change the username on that page. But when I go to another Component (page) and back, the username isn't saved.

I also want to show the username in the other components. How do I do that? With a global variable?

Structure: 
- App
 - app.ts (main)
 - setting.ts
 - someOtherComponent.ts