Redux Toolkit Tutorial - 3 - Three Core Concepts

Introduction

In this tutorial, we will explore the three core concepts of Redux, as presented in the Redux Toolkit Tutorial by Codevolution. Understanding these concepts is essential for effectively managing state in your applications using Redux. We will break down each concept into actionable steps to help you grasp their significance and implementation.

Step 1: Understanding Actions

Actions are plain JavaScript objects that have a type and, optionally, a payload. They are the primary way to send data from your application to your Redux store.

• Define Action Types

  • Create constants for your action types to avoid typos.
  • Example:

    const ADD_TODO = 'ADD_TODO';
    const REMOVE_TODO = 'REMOVE_TODO';
    

• Create Action Creators

  • These are functions that return action objects.
  • Example:

    const addTodo = (todo) => ({
      type: ADD_TODO,
      payload: todo,
    });
    
    const removeTodo = (id) => ({
      type: REMOVE_TODO,
      payload: id,
    });
    

Practical Tips

• Use descriptive names for action types for clarity.
• Keep the payload minimal and relevant.

Step 2: Understanding Reducers

Reducers are pure functions that take the current state and an action as arguments and return a new state.

• Define the Initial State

  • Start with a default state for your reducer.
  • Example:

    const initialState = {
      todos: [],
    };
    

• Create the Reducer Function

  • Implement the logic to handle different action types.
  • Example:

    const todoReducer = (state = initialState, action) => {
      switch (action.type) {
        case ADD_TODO:
          return {
            ...state,
            todos: [...state.todos, action.payload],
          };
        case REMOVE_TODO:
          return {
            ...state,
            todos: state.todos.filter(todo => todo.id !== action.payload),
          };
        default:
          return state;
      }
    };
    

Common Pitfalls to Avoid

• Do not mutate the state directly; always return a new object.
• Ensure all action types are handled appropriately in the reducer.

Step 3: Understanding Store

The store brings together the state, actions, and reducers. It allows you to manage the application's state in a centralized location.

• Create the Store

  • Use Redux's createStore function to instantiate the store.
  • Example:

    import { createStore } from 'redux';
    
    const store = createStore(todoReducer);
    

• Accessing State and Dispatching Actions

  • Use store.getState() to retrieve the current state.
  • Use store.dispatch(action) to send actions to the reducer.
  • Example:

    store.dispatch(addTodo({ id: 1, text: 'Learn Redux' }));
    console.log(store.getState());
    

Real-World Applications

• Use the Redux store for managing global state in applications, such as user authentication, shopping cart data, or UI states across different components.

Conclusion

In this tutorial, we covered the three core concepts of Redux: actions, reducers, and the store. By understanding and implementing these concepts, you can effectively manage application state using Redux. As a next step, consider exploring middleware, such as Redux Thunk or Redux Saga, to handle asynchronous actions in your application.