Introduction

Redux is a great tool that addresses one of the main problems of UI frameworks: state management. The unidirectional data flow model makes it easy to understand how events change the state. However, there’s one problem Redux doesn’t solve out of the box: the management of side effects.

Side effects are functions that modify the state value outside of their local environment. Contrary to the name, they are not unexpected and, at times, may be exactly what you need.

Actions are descriptions of events originated by a user, a network call, or a timer. In some cases, a single action might generate multiple other actions synchronously or asynchronously.