Modern React Redux Tutorials with Redux toolkit - 2020

This tutorial explain how you can build an application using modern react redux with redux toolkit. Modern React Redux Tutorials with Redux toolkit - 2020.

Things are changing in front end application development. What we have been using to develop a frontend application is constantly changing to build things faster and efficient. One of them is redux, there are lots of state management options out there to react. but, we have to admit that redux is popular among them.

So, what changed in redux?.. well we are about to find out in this article. Buckle up to learn in this react with redux tutorial.

Note: I assume that you are familiar with redux concepts. If you are new to Redux, I recommend you to checkout this course.

Before we get into the article, let me show you what we are going to build in this article.

Demo

This is a simple Forum where you can post a question and comment on it.

What Changed in Redux?

Well, the core concepts of redux remain the same. But, the way we implement things is changed in the react-redux environment. With a package called redux-toolkit, we can implement redux in our react application in an easy way.

Setting up redux boilerplate is cumbersome in previous days. redux-toolkit solves that problem for us. Let's see how to use redux-toolkit to build an application.

Core Concepts of Redux toolkit

there are few important changes in the redux toolkit, let's see them

configureStore

we all know that redux store(createStore) handles the actions and reducer in redux. well, configure store is an wrapper around createStore with some default configuration options. it simplifies some configuration pains.

createAction

createAction returns an action creator function. one important change to note here is that we return an action creator function not an object. in old traditional way, it returns an object with type and payload.here, we return a function .

1// Original approach: write the action type and action creator by hand
2const INCREMENT = "INCREMENT"
3
4function incrementOriginal() {
5  return { type: INCREMENT }
6}
7
8console.log(incrementOriginal())
9// {type: "INCREMENT"}
10
11// Or, use `createAction` to generate the action creator:
12const incrementNew = createAction("INCREMENT")
13
14console.log(incrementNew())
15// {type: "INCREMENT"}

createReducer

Let me show two versions of code, see and think which one is more easier to manage.

1//redux action
2const increment = payload => {
3  return {
4    type: "INCREMENT",
5    payload,
6  }
7}
8
9//redux reducer function
10export default reducer = (state, action) => {
11  switch (action.type) {
12    case "INCREMENT":
13      return {
14        ...state,
15        payload,
16      }
17    default:
18      return state
19  }
20}

Let's look at an another version of code

1const increment = createAction("INCREMENT")
2const decrement = createAction("DECREMENT")
3
4const counter = createReducer(0, {
5  [increment]: state => state + 1,
6  [decrement]: state => state - 1,
7})

you can see the difference. right?. well that's makes a lot difference when your application grows. it will easy to maintain in the later version.

createReducer takes initialState and action creator function and use a concepts lookup table which takes the object key and compares it with action creator and match with the reducer. In that way, you don't need to manually write a if..else or switch case state to manage it.

createSlice

If you think, it's cutting down from writing lots of code. well, there is more. createSlice provides an option to generate action creator and action types for. you only need to specify the reducer function, initial state, and name for the slice and createSlice take care of everything for you.

1const counterSlice = createSlice({
2  name: "counter",
3  initialState: 0,
4  reducers: {
5    increment: state => state + 1,
6    decrement: state => state - 1,
7  },
8})
9
10const store = configureStore({
11  reducer: counterSlice.reducer,
12})
13
14document.getElementById("increment").addEventListener("click", () => {
15  store.dispatch(counterSlice.actions.increment())
16})

Getting Started

Let's start with create-react-app with redux toolkit template included on it.

1npx create-react-app my-app --template redux

Above command creates a boilerplate for us with recommended folder structure(feature folder) and a simple example code.

Every domain is considered as a feature here. it's better to wrap the functionalities of a particular domain in one feature folder. checkout this article to learn more about it.

Learning bit: https://github.com/erikras/ducks-modular-redux

In our application, there are three domains that we need to cover. they are,

So, create folder structure based on the above domains.

Now, it is time to create redux part of our features.

Questions Feature

Let's take the Questions part. it will contains functionalities such as

Add Question
Edit Question
Remove Question

we need to use createSlice to create reducer and action creator function. before that, import create slice from toolkit.

1import { createSlice } from "@reduxjs/toolkit";
2
3create a slice function with name, initial State and reducer function.
4
5    export const questionSlice = createSlice({
6      name: "questions",
7      initialState: [],
8      reducers: {
9        addQuestion: (state, action) => {
10          //Add Question reducer function
11        },
12        editQuestion: (state, action) => {
13          //Edit Question Reducer function
14        },
15        removeQuestion: (state, action) => {
16          //Remove Question Reducer function
17        },
18      },
19    });

Once we create that, we can be able to get all the actions from the slice itself. Here, we have reducer functions addQuestion,editQuestion and removeQuestion. so, createSlice will generate three action creator function with exact name on it.

1export const {
2  addQuestion,
3  editQuestion,
4  removeQuestion,
5} = questionSlice.actions

After that, you can write the selector and export the reducer from here.

1export const selectQuestions = state => state.questions
2
3export default questionSlice.reducer

Once you're done with your slice function. map the reducer with redux store.

1import { configureStore } from "@reduxjs/toolkit"
2import questionReducer from "../features/Questions/questionSlice"
3export default configureStore({
4  reducer: {
5    questions: questionReducer,
6  },
7})

Now, we can use the action and selector in our component. create a component Questions.js with basic setup

1iimport React, { useState } from "react";
2    import { useDispatch, useSelector } from "react-redux";
3    import styled from "styled-components";
4
5    import {
6      selectQuestions,
7      addQuestion,
8      removeQuestion,
9      editQuestion,
10    } from "./questionSlice";
11
12
13    const Questions = () => {
14
15    const [showAddQuestion, setShowAddQuestion] = useState(false);
16
17      const questions = useSelector(selectQuestions);
18      const dispatch = useDispatch();
19
20
21      const onSubmit = () => {
22
23      };
24
25      return (
26        <Container>
27          <QuestionsContainer>
28                    //Questions Array comes Here
29            {questions && questions.length > 0 ? (
30              questions.map((question, index) => {
31                return (
32                   <div>{question}</div>
33                );
34              })
35            ) : (
36              <div>No Data Found</div>
37            )}
38          </QuestionsContainer>
39          <AddQuestionButtonContainer onClick={() => setShowAddQuestion(true)}>
40            <AddQuestionIcon src={plus_icon} />
41            <AddQuestionName>Add Question</AddQuestionName>
42          </AddQuestionButtonContainer>
43
44
45                //When User clicks the add Question, we need to show the Form
46          {showAddQuestion ? (
47            <FormContainer>
48              <FormContainerDiv>
49                <FormLabel>Title</FormLabel>
50                <FormContainerTitleInput
51                  type="text"
52                  value={title}
53                  onChange={(e) => setTitle(e.target.value)}
54                />
55              </FormContainerDiv>
56
57              <FormContainerDiv>
58                <FormLabel>Body</FormLabel>
59                <FormContainerBodyInput
60                  type="textarea"
61                  value={body}
62                  onChange={(e) => setBody(e.target.value)}
63                />
64              </FormContainerDiv>
65              <AddQuestionButton onClick={onSubmit}>Submit</AddQuestionButton>
66            </FormContainer>
67          ) : (
68            ""
69          )}
70        </Container>
71      );
72    };
73
74    export default Questions;

On the above code, we are using redux hooks useDispatch and useSelector for redux actions and selector.

Firstly, we import the actions and selectors from the slice file.

1import {
2  selectQuestions,
3  addQuestion,
4  removeQuestion,
5  editQuestion,
6} from "./questionSlice"

After that, we use the selectQuestions in useSelector to get all the data from store.

1const questions = useSelector(selectQuestions)

Then, we render the data in our component

1{
2  questions && questions.length > 0 ? (
3    questions.map((question, index) => {
4      return (
5        <QuestionListItem key={index}>
6          <Link to={`/question/${question.id}`}>
7            <QuestionTitle>{question.title}</QuestionTitle>
8          </Link>
9        </QuestionListItem>
10      )
11    })
12  ) : (
13    <div>No Data Found</div>
14  )
15}

finally, we have a form which user uses submits the question.

1<FormContainer>
2  <FormContainerDiv>
3    <FormLabel>Title</FormLabel>
4    <FormContainerTitleInput
5      type="text"
6      value={title}
7      onChange={e => setTitle(e.target.value)}
8    />
9  </FormContainerDiv>
10
11  <FormContainerDiv>
12    <FormLabel>Body</FormLabel>
13    <FormContainerBodyInput
14      type="textarea"
15      value={body}
16      onChange={e => setBody(e.target.value)}
17    />
18  </FormContainerDiv>
19  <AddQuestionButton onClick={onSubmit}>Submit</AddQuestionButton>
20</FormContainer>

when user clicks the onSubmit, we need to dispatch action prior to it.

1const onSubmit = () => {
2  let data = {
3    id: questions.length + 1,
4    title: title,
5    body,
6  }
7
8  dispatch(addQuestion(data))
9}

Well, that's pretty much of a getting the data and dispatching an action in redux lifecycle.

QuestionDetails Feature

1import React, { useState } from "react"
2import styled from "styled-components"
3import { useSelector } from "react-redux"
4import { useParams, useHistory } from "react-router-dom"
5
6import Comments from "../Comments/Comments"
7
8const Container = styled.div`
9  width: 100vw;
10  height: 100vh;
11  background-color: #efecec;
12`
13
14const QuestionsContainer = styled.div`
15  display: flex;
16  flex-flow: column;
17  padding: 3.75rem 5rem;
18  width: 20%;
19  box-shadow: 0 0.125rem 0.375rem rgba(0, 0, 0, 0.2);
20  border-radius: 0.3125rem;
21  background: #fff;
22  margin: auto;
23`
24
25const Heading = styled.h2``
26
27const QuestionLabel = styled.h4`
28  font-weight: 300;
29`
30
31const QuestionDetail = props => {
32  const { id } = useParams()
33  if (!id) {
34  }
35  const questionDetail = useSelector(state => {
36    let question = state.questions.find(question => question.id == id)
37
38    return question
39  })
40
41  return (
42    <Container>
43      <QuestionsContainer>
44        <Heading>Title:</Heading>
45        <QuestionLabel>{questionDetail && questionDetail.title}</QuestionLabel>
46        <Heading>Body:</Heading>
47        <QuestionLabel>{questionDetail && questionDetail.body}</QuestionLabel>
48      </QuestionsContainer>
49      {questionDetail ? <Comments id={questionDetail.id} /> : null}
50    </Container>
51  )
52}
53
54export default QuestionDetail

it contains the details of the questions and comments component. from here, we pass the question id as a props to Comments component

Also, we use useSelector to fetch the questions data from the redux store.

Comments Feature

Now, it's time to create slice for comments feature. Here, we need functionalities such as

Add Comment
Edit Comment
Remove Comment

1import { createSlice } from "@reduxjs/toolkit"
2
3export const commentSlice = createSlice({
4  name: "comments",
5  initialState: [],
6  reducers: {
7    addComment: (state, action) => {
8      //Add Comment Reducer
9    },
10    editComment: (state, action) => {
11      //Edit Comment Reducer
12    },
13    removeComment: (state, action) => {
14      //Remove Comment Reducer
15    },
16  },
17})

After that, we export the action creator function, selectors and reducer functions.

1export const { addComment, editComment, removeComment } = commentSlice.actions
2
3export const comments = state => state.comments
4
5export default commentSlice.reducer

Finally, update the store with comments reducer function

1import { configureStore } from "@reduxjs/toolkit"
2import questionReducer from "../features/Questions/questionSlice"
3import commentReducer from "../features/Comments/commentsSlice"
4export default configureStore({
5  reducer: {
6    questions: questionReducer,
7    comments: commentReducer,
8  },
9})

Comments.js

1import React, { useState } from "react"
2import styled from "styled-components"
3import { useSelector, useDispatch } from "react-redux"
4
5import { addComment } from "./commentsSlice"
6
7const CommentsContainer = styled.div``
8
9const CommentHeading = styled.h4``
10
11const CommentLists = styled.ul`
12  text-decoration: none;
13  list-style: none;
14  display: flex;
15  flex-flow: column;
16  padding: 1.75rem;
17  max-height: 200px;
18  overflow: auto;
19`
20
21const AddCommentsInput = styled.input`
22  width: 10%;
23  height: 32px;
24  border-radius: 8px;
25`
26
27const CommentListItem = styled.div`
28  padding: 10px;
29`
30
31const CommentTitle = styled.div``
32
33const Comments = ({ id }) => {
34  const [comment, setComment] = useState("")
35
36  const comments = useSelector(state => {
37    let comments = state.comments.filter(comment => comment.questionId == id)
38
39    return comments
40  })
41  const dispatch = useDispatch()
42
43  const onAddComment = e => {
44    if (e.key !== "Enter") {
45      return
46    }
47
48    if (e.key === "Enter") {
49      let data = {
50        id: comments && comments.length > 0 ? comments.length + 1 : 1,
51        comment: comment,
52        questionId: id,
53      }
54
55      dispatch(addComment(data))
56      setComment("")
57    }
58  }
59  return (
60    <div>
61      <CommentsContainer>
62        <CommentHeading>Comments</CommentHeading>
63        <CommentLists>
64          {comments &&
65            comments.map(comment => (
66              <CommentListItem key={comment.id}>
67                <CommentTitle>{comment.comment}</CommentTitle>
68              </CommentListItem>
69            ))}
70        </CommentLists>
71        <AddCommentsInput
72          type="text"
73          value={comment}
74          onChange={e => setComment(e.target.value)}
75          onKeyPress={onAddComment}
76        />
77      </CommentsContainer>
78    </div>
79  )
80}
81
82export default Comments

Complete source code can be found here

Summary

Let me give you a quick summary of what we have seen so far. there are four main concepts in redux toolkit. configureStore, createAction, createReducer and createSlice. each of them makes our redux development easier. Mainly, createSlice helps us to generates the action creator function and action types just by taking the reducers of the domain. All other concepts remains the same on the application development.

That's it for this article. Learn it and Practice to get better at react redux application development. Happy Coding :-)