React.js Essentials

Chapter 6. Update Your React Components

In the previous chapter, we learned that a React component can go through three phases:

• Mounting
• Updating
• Unmounting

We've already discussed the mounting and unmounting phases. In this chapter, we're going to focus on the updating phase. During this phase, a React component is already inserted into the DOM. This DOM represents a component's current state, and when that state changes, React needs to evaluate how a new state is going to mutate the previously rendered DOM.

React provides us with methods to influence what is going to be rendered during an update as well as to make us aware of when an update happens. These methods allow us to control the transition from the current component's state to the next component's ...