Introduction

In this blog post, we’ll delve into three advanced React Hooks – `useContext`, `useImperativeHandle`, and `useReducer`. These Hooks enable efficient component management and state handling, helping to build more complex and scalable React applications.

useContext

`useContext` allows you to share state and other data between components without having to pass props down manually from a parent to every child. It creates a React context and returns the current context value.

Here’s a basic example:

“`javascript
import React, { createContext, useContext } from ‘react’;

const MyContext = createContext();

const MyProvider = MyContext.Provider;
const MyConsumer = MyContext.Consumer;

function App() {
const [value, setValue] = React.useState(‘default value’);

return (




);
}

function MyComponent() {
const value = useContext(MyContext);
// Use the value here
return

;
}

function MyOtherComponent() {
return

;
}
“`

useImperativeHandle

`useImperativeHandle` lets you attach a ref instance to a custom React component and give it instance methods. This can be useful when integrating with legacy code or when using third-party libraries that require direct access to the underlying DOM node or instance.

Here’s an example:

“`javascript
import React, { forwardRef, useImperativeHandle } from ‘react’;

const FancyButton = forwardRef((props, ref) => {
const inputRef = React.useRef(null);

useImperativeHandle(ref, () => ({
focus: () => {
inputRef.current.focus();
},
}));

return ;
});

function App() {
const buttonRef = React.useRef(null);

return ;
}

// Now you can call focus on the button ref
ReactDOM.render(, document.getElementById(‘root’));
buttonRef.current.focus();
“`

useReducer

`useReducer` is a Hook that helps you manage complex state patterns in functions components. It accepts a reducer function and an initial state value. The reducer function should be a pure function that takes the current state and an action, and returns the next state.

Here’s an example using `useReducer` to manage the state of a form:

“`javascript
import React, { useReducer } from ‘react’;

const initialFormState = { firstName: ”, lastName: ” };

const reducer = (state, action) => {
switch (action.type) {
case ‘UPDATE_FIRST_NAME’:
return { …state, firstName: action.payload };
case ‘UPDATE_LAST_NAME’:
return { …state, lastName: action.payload };
default:
throw new Error();
}
};

function Form() {
const [formState, dispatch] = useReducer(reducer, initialFormState);

const handleFirstNameChange = (event) => {
dispatch({ type: ‘UPDATE_FIRST_NAME’, payload: event.target.value });
};

const handleLastNameChange = (event) => {
dispatch({ type: