Building a Redux store from scratch in JavaScript

13 Sep 2023

redux

Redux is a popular state management library used in JavaScript applications. While there are various libraries available that provide pre-built Redux stores, understanding the inner workings of Redux can be beneficial for customizing and optimizing your application’s state management.

In this blog post, we will guide you through building a Redux store from scratch using JavaScript. By the end of this tutorial, you will have a solid understanding of how Redux works and how to implement your own state management solution.

Prerequisites

To follow along with this tutorial, make sure you have a basic understanding of JavaScript and familiarity with concepts such as actions, reducers, and store.

Setting up the Project

Let’s start by setting up a basic project structure:

Create a new directory for your project.
Inside the project directory, create a file named store.js.

Implementing the Redux Store

Now let’s dive into implementing the Redux store step by step.

Step 1: Define the Initial State

The initial state of your application will hold all the necessary data. Define an object representing the initial state inside the store.js file:

const initialState = {
  // Define your initial state properties here
};

Step 2: Create Actions

Actions represent the various operations that can be performed on the state. Define a function for each action you want to handle:

const increment = () => ({ type: 'INCREMENT' });
const decrement = () => ({ type: 'DECREMENT' });

Step 3: Create a Reducer

A reducer is a pure function that takes in the current state and an action, and returns the new state based on the action type. Create a reducer function inside the store.js file:

const reducer = (state = initialState, action) => {
  switch (action.type) {
    case 'INCREMENT':
      // Handle the increment action
      return {
        ...state,
        count: state.count + 1
      };
    case 'DECREMENT':
      // Handle the decrement action
      return {
        ...state,
        count: state.count - 1
      };
    default:
      return state;
  }
};

Step 4: Create the Redux Store

Now, it’s time to create the Redux store. Import the createStore function from the Redux library and create the store with the reducer:

const { createStore } = require('redux');

const store = createStore(reducer);

Step 5: Dispatching Actions

To update the state, you need to dispatch actions to the store. Use the dispatch method provided by the store to dispatch actions:

store.dispatch(increment());
store.dispatch(decrement());

Step 6: Subscribing to Store Changes

To listen for changes to the state, you can subscribe to the store. Whenever the state changes, the subscribed function will be called:

store.subscribe(() => {
  const currentState = store.getState();
  console.log('Current State:', currentState);
});

Conclusion

Congrats! You have successfully built a Redux store from scratch in JavaScript. You can now create, dispatch, and manage actions to update your application state using Redux.

Remember that Redux is a powerful state management tool that allows your application to handle complex state interactions. By understanding the core concepts and implementing your own Redux store, you can customize Redux to fit your specific needs.

Stay tuned for more blog posts on how to extend and optimize your Redux store! ✨