Exploring StateFlow and SharedFlow

In this section, we will dive into StateFlow and SharedFlow. SharedFlow and StateFlow are Flows that are hot streams, unlike a normal Kotlin Flow, which are cold streams by default.

A Flow is a cold stream of data. Flows only emit values when the values are collected. With SharedFlow and StateFlow hot streams, you can run and emit values the moment they are called and even when they have no listeners. SharedFlow and StateFlow are Flows, so you can also use operators on them.

A SharedFlow allows you to emit values to multiple listeners. SharedFlow can be used for one-time events. The tasks that will be done by the SharedFlow will only be run once and will be shared by the listeners.

You can use MutableSharedFlow and then use the emit function to send values to all the collectors.

In the following example, SharedFlow is used in MovieViewModel for the list of movies fetched:

class MovieViewModel : ViewModel() {

    ...