3.10 Observers

3.10.1 When might you use an observer?

• Anytime you need to make a call out of the application.
  • Saving a file to a shared drive
  • Sending data to an API
  • Updating a database
  • Printing a debugging message
• Observers don’t affect how the app looks.

There are two important differences between observeEvent() and eventReactive():

1. You don’t/can’t assign the result of observeEvent() to a variable, so
   
2. You can’t refer to it from other reactive consumers.