Summary

This chapter covered additional aspects of the ComposeUnitConverter example. We continued the exploration of the ViewModel pattern we began looking at in the Using ViewModel section of Chapter 5, Managing State of Your Composable Functions. This time, we added business logic to the ViewModel and injected an object that can persist and retrieve data.

The Keeping your composables responsive section revisited one of the key requirements of a composable function. Recomposition can occur very often, therefore composables must be as fast as possible, which in turn dictates what the code inside them can and cannot do. I showed you how a simple loop can cause a Compose app to stop responding, and how coroutines are used to counteract this.

In the final main section, Understanding side effects, we examined so-called side effects and used LaunchedEffect and DisposableEffect to implement a simple counter.

In Chapter 8, Working with Animations, you will learn how to show and hide...