Facebook supports the open-source React JavaScript library. It’s a user interface framework that’s declarative, efficient, and adaptable. Creating interactive user interfaces and component-centric applications that are responsive and backward compatible is simple. React has grown in popularity during the last few decades due to the freedom it affords to developers. The following statistics demonstrate React’s widespread adoption:
- React is the most used front-end framework, according to the state of the js report.
- React.js has surpassed jQuery as the most widely used web framework, according to the StackOverflow annual developer survey 2021.
- According to Builtwith, React is used by 10,719,651 live websites worldwide.
React components follow a lifecycle from beginning to end. The initial mounting, updating, and unmounting stages of your component’s lifespan are all represented by this lifecycle. Every phase provides a few modules that developers can customize to give the component the ability to respond to changes. The popularity of React can be seen from the following figures:
During the life of each component, all of the lifecycle methods do not have to be run. In simple words, the development of a react component can be seen as the component’s “lifetime.” These procedures are events that occur during the component’s lifecycle phases.
When you hire reactjs developers, you can be confident that lifecycle methods are called at the correct times during a component’s lifespan, ensuring that the application runs smoothly. There are four phases in the lifespan of react components.
- Initialization
Using the constructor, the component is created with the basic parameters and default states in this stage.
- Mounting
The mounting stage is where the JSX provided through the render method is rendered.
- Updating
As the name suggests, the update stage component is modified, and the application is refreshed.
- Unmounting
Unmounting is the last phase in the component lifecycle, and it involves removing the component of the page.
React Lifecycle Methods
The official react document contains a valuable component lifecycle diagram that shows how all of the methods are executed top-down. Let’s start with the early step of the component’s development.
Initial
It is the starting point of the lifespan of a ReactJS component. The component embarks on its path to the DOM from this point. A component’s default Props and starting State are available during this phase. A component’s constructor is where these initial properties are set. The following approaches are used in the first phase, which occurs only once.
getDefaultProps()
It’s used to set the. Props default value. Before the component is created or any parent props are supplied into it, it is called.
getInitialState()
This. State’s default value is specified using it. It is called before the component is created.
Mounting Phase
The instance of elements is produced and inserted in the DOM during this phase of the react component. React contains four built-in methods, which are named in the following order:
componentWillMount()
This method is called just before a component is rendered into the DOM. The element will not re-render in this scenario if you execute setState() inside this function.
getDerviedStateFromProps()
Prior to rendering the element(s) in the DOM, the getDerivedStateFromProps() function is executed. Setting the state object depending on the original props makes sense here. It accepts the state as an input and gives an object that contains the state’s modifications.
componentDidMount()
This function is called immediately after the component is rendered and placed in the DOM. After that, you can do whatever DOM querying you want.
render()
Almost every component defines this method. It’s in charge of returning a single HTML node element as the root element. You must provide a null or false value if you do not want to render anything.
Updating
The Updating phase of the React component lifecycle is the following step. When the state of a component or the props passed to it change, the component is updated. This phase’s primary goal is to verify that the component is showing the most recent version. This condition, unlike others in the component, repeats itself. This component has five methods, which are listed below:
componentWillRecieveProps()
When a component gets new props, this method is called. It would be best if you compare this. Props and next. Props if you wish to modify the state in response to prop changes. This.setState() method is used to perform state transitions.
shouldComponentUpdate()
It is called when an element decides to make modifications to the DOM. It enables you to regulate how the component updates itself. The component will be updated if the same method returns true. If this is not the case, the component will not update.
componentWillUpdate()
It’s called right as the component is about to be updated. This does not allow you to change the status of the component. The method setState() is used to change the system’s current state. ShouldComponentUpdate() returns false, then it will not be called.
render()
It is used to explore this. Props, as well as this, React elements, Arrays, and fragments, Booleans or null, String, and Number are all kinds that can be returned. If shouldComponentUpdate() returns false, the render() function will be run again to ensure that the component shows correctly.
componentDidUpdate()
It is utilized immediately following the component’s update. You can use this function to put any code you wish to run when the upgrade is finished. This method is not used in the first render.
Unmounting Phase
When a component is killed and unmounted from DOM, the lifecycle moves to the next phase. There is only one procedure in this phase, which is the following.
componentWillUnmount()
Before a component is permanently deleted and unmounted, this procedure is called. It invalidates event listeners, cancels network requests, and cleans up DOM components, among other things. You cannot remount a component instance that has been unmounted.
Wrapping up!
All of the lifecycle methods in React’s most recent build are listed here. One of the fundamental aspects of React that any developer should understand if they want to improve their skills is knowing when to use them. Each of these techniques has a purpose, but some are utilized more frequently than others. The render method is the only one that must be used throughout the entire lifespan (). Those lifecycle techniques, it may be claimed, are the ones that provide true reaction power.
