Hands-On Microservices with Kotlin

Understanding subscribers and publishers

First, we need to understand a core component in reactive programming, the subscribe and publish mechanism. Reactive programming is based on the event-model mechanism, in which a set of events are triggered and dispatched to whoever needs them. This abstract concept can easily be understood with how we handle actions from users in almost all UI Frameworks.

Let's think that we want to react to a UI action, for example, pressing a button and then performing an operation such as closing a window. In a normal UI Framework, user actions such as pressing buttons, selecting menus, or scrolling the contents of a window can be considered events. When we choose to listen to those events, what we are defining ...