Unidirectional State Management: How React's useReducer Implements the Flux Pattern
Tags: webdev, javascript, react, tutorial
Published: 2023-03-24 17:56:45

React is one of the most popular JavaScript libraries for building user interfaces. With its declarative approach and efficient rendering, React has revolutionized the way we think about front-end development. One of the key features of React is its ability to manage state, which is essential for building complex user interfaces. In this article, we'll take a closer look at React's useReducer hook and how it implements the Flux pattern.

**What is the Flux pattern?**
Flux is a pattern for managing state in web applications. It was first introduced by Facebook in 2014 as a way to solve some of the problems they were encountering while building large-scale applications with React. The Flux pattern consists of four components: Actions, Dispatcher, Stores and Views. Check more details on the [Flux Pattern](https://dev.to/judeebekes67/how-react-follows-the-flux-pattern-22co)

The key benefit of the Flux pattern is that it provides a unidirectional data flow, which makes it easier to reason about and debug complex applications. It also makes it easier to scale the application as it grows.

**What is useReducer?**
useReducer is a hook provided by React that allows you to manage state using a reducer function. The reducer function takes two arguments: the current state and an action object, and returns the new state. It follows the same pattern as the reducer function used in the Array.reduce method.

Here's an example of a reducer function:

```
function counterReducer(state, action) {
  switch (action.type) {
    case 'INCREMENT':
      return state + 1;
    case 'DECREMENT':
      return state - 1;
    default:
      return state;
  }
}
```
The reducer function used with the useReducer hook takes the current state and an action object as arguments, and returns the new state based on the type of action. In the example given, the state represents a counter and is initialized as a number. The action objects contain a type property that describes the action to be performed, such as incrementing or decrementing the counter. It is recommended to declare the reducer function outside of the React component to keep the component's code clean and modular. This also allows the same reducer function to be reused across multiple components if needed.

Here's an example of how to use the useReducer hook to manage state:

```
import React, { useReducer } from 'react';

function Counter() {
  const [count, dispatch] = useReducer(counterReducer, 0);
  function handleIncrement() {
    dispatch({ type: 'INCREMENT' });
  }
  function handleDecrement() {
    dispatch({ type: 'DECREMENT' });
  }
  return (
    <div>
      <p>Count: {count}</p>
      <button onClick={handleIncrement}>Increment</button>
      <button onClick={handleDecrement}>Decrement</button>
    </div>
  );
}
```
In the example given, we are utilizing the useReducer hook to manage the state of a counter. We pass in the `counterReducer` function as the reducer argument and initialize the state to zero. We then use the dispatch function returned by the useReducer hook to send actions, also known as Payload, to the reducer function. How then does the useReducer hook implements the flux pattern.

**How useReducer implements the Flux pattern**
The useReducer hook implements the Flux pattern by providing a way to manage state in a unidirectional data flow. When an action is dispatched to the reducer using the dispatch function returned by the useReducer hook, it updates the state and triggers a re-render of the React component. This re-rendering causes the view to update based on the new state.

The useReducer hook also provides a way to share state between components. By using a reducer function to manage the state, we can pass the state and the dispatch function down as props to child components, allowing them to update the state as well.

Conclusion
React does React's.


🎉🎉😎🎉🎉 Check my previous articles: [Exploring How React Follows the Flux Pattern for Building User Interfaces](https://dev.to/judeebekes67/how-react-follows-the-flux-pattern-22co)