Learn Redux Toolkit By Todo List App

Redux Toolkit is the official, opinionated, batteries-include toolset for efficient Redux development

Introduction

Redux is a state management for frontend lib, like React. It is complex and not easier to use and understand. So the Redux Toolkit is out. Less code, less api, but more powerful. In this tutorial, I do not introduce what is redux, I will explain how to use it in a little app. I prefer to use Redux Toolkit in your project. I also show how to use typescript with redux.

The UI

The UI such like this below. Not focus on css, very simple.

• click the "play" can change it to done
• click the doing or done button can change the status to filter the todo list

Create Project

Now we should use Create React App tool to init our project.

npx create-react-app todoList --template typescript

Create the static page

• create components
• change App.tsx

import TodoList from "./components/TodoList/TodoList";
import Filter from "./components/Filter/Filter";
import SearchPanel from "./components/SearchPanel/SearchPanel";
import "./App.css";

function App() {
  return (
    <div className="main">
      <SearchPanel />
      <div className="todoList">
        <TodoList />
      </div>
      <Filter />
    </div>
  );
}

export default App;

Use Redux Toolkit

Install Redux Toolkit

Also need to install react-redux

npm install @reduxjs/toolkit react-redux

Create Store

Store is where the state is stored globally

Create store file

config store

use configureStore api to create store. Now we create an empty store

import { configureStore } from '@reduxjs/toolkit'

export const store = configureStore({
  reducer: {},
})

export type RootState = ReturnType<typeof store.getState>
export type AppDispatch = typeof store.dispatch

Provide redux store to react

change index.tsx file

import React from "react";
import ReactDOM from "react-dom/client";
import "./index.css";
import App from "./App";
import reportWebVitals from "./reportWebVitals";
import { store } from "./app/store";
import { Provider } from "react-redux";

const root = ReactDOM.createRoot(
  document.getElementById("root") as HTMLElement
);
root.render(
  <React.StrictMode>
    <Provider store={store}>
      <App />
    </Provider>
  </React.StrictMode>
);

// If you want to start measuring performance in your app, pass a function
// to log results (for example: reportWebVitals(console.log))
// or send to an analytics endpoint. Learn more: https://bit.ly/CRA-vitals
reportWebVitals();

Create Redux State Slice

Add two slice file named filter and todoList

/src/features/filter/filterSlice.ts

import { createSlice, PayloadAction } from "@reduxjs/toolkit";

export type StatusType = 'all' | 'done' | 'doing'

interface FilterProps {
  status: StatusType
}

const initialState: FilterProps = {
  status: 'all'
}

export const filterSlice = createSlice({
  name: 'filter',
  initialState,
  reducers: {
    changeStatus: (state, action: PayloadAction<StatusType>) => {
      state.status = action.payload
    }
  },
})

export const { changeStatus } = filterSlice.actions

export default filterSlice.reducer;

/src/features/todoList/todoListSlice.ts

import { createSlice, PayloadAction } from '@reduxjs/toolkit'

interface TodoListProps {
  allTodo: TodoItemProps[]
}

export interface TodoItemProps {
  id: string
  name: string
  isComplete: boolean
}

const initialState: TodoListProps = {
  allTodo: [{id: '0', name: 'play', isComplete: false}]
};

export const todoListSlice = createSlice({
  name: 'todoList',
  initialState,
  reducers: {
    addItem: (state, action: PayloadAction<string>) => {
      const item: TodoItemProps = {
        id: (Math.random() * 1000000).toFixed(0),
        name: action.payload,
        isComplete: false,
      }
      state.allTodo.push(item);
    },
    changeItemStatus: (state, action: PayloadAction<string>) => {
      const item = state.allTodo.find((item) => item.id === action.payload)
      if (item) {
        item.isComplete = !item.isComplete;
      }
    },
  }
})

export const { addItem, changeItemStatus } = todoListSlice.actions;

export default todoListSlice.reducer;

Create a slice require a string name identify slice, need a initialState, and one or more reducer functions to define how the state can be updated

then export the action creators and reducer for the whole slice

Add Slice Reducers to the Store

Just import all reducers and add to the store

import { configureStore } from '@reduxjs/toolkit'
import todoListReducer from '../features/todoList/todoListSlice'
import filterReducer from '../features/filter/filterSlice'

export const store = configureStore({
  reducer: {
++    todoList: todoListReducer,
++    filter: filterReducer,
  },
})

export type RootState = ReturnType<typeof store.getState>
export type AppDispatch = typeof store.dispatch

Use The State

Use State

We can use useSelector to get the state

import { useSelector } from "react-redux";
import { RootState } from "../../app/store";

const filter = useSelector((state: RootState) => state.filter.status);

Change State

import { useDispatch } from "react-redux";
import { changeStatus } from "../../features/filter/filterSlice";

const dispatch = useDispatch();

dispatch(changeStatus(status));

For now we can get state and can change state, the todoList slice is same, you can clone this github repository to get all code

Final Output

Conclusion

When you need to use Redux in your project, I prefer Redux Toolkit than regular redux way. This way less code, less api, easier to understand. And it contain redux-thunk, I will update this part.

That’s all, Thank you.