Modern React Redux Toolkit - Login & User Registration Tutorial and Example

User Authentication is one of the common workflow in web applications. In this tutorial, we will see how to build a User Login and Signup workflow with Modern react redux toolkit.

Demo

App Demo

Let's scaffold an application using the command,

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

If you're completely new to redux-toolkit, checkout this article to learn the basic concepts of redux toolkit.

Let me give you a glimpse about the concepts of redux toolkit. Everything in toolkit is grouped as Features. it's called duck pattern.

Action and Reducers are combined in redux toolkit as Slice. To make HTTP API call, we will be using createAsyncThunk. We will discuss about it in detail in the later part of the article.

Create App.js

1import React from 'react';
2import './App.css';
3import { BrowserRouter as Router, Switch, Route, Link } from 'react-router-dom';
4import Login from './features/User/Login';
5import Signup from './features/User/Signup';
6import Dashboard from './features/User/Dashboard';
7import { PrivateRoute } from './helpers/PrivateRoute';
8
9function App() {
10  return (
11    <div className="App">
12      <Router>
13        <Switch>
14          <Route exact component={Login} path="/login" />
15          <Route exact component={Signup} path="/signup" />
16          <PrivateRoute exact component={Dashboard} path="/" />
17        </Switch>
18      </Router>
19    </div>
20  );
21}
22
23export default App;

Before creating components for the workflow. let's create redux slice for our User section. create UserSlice.js inside features/User directory,

1import { createSlice, createAsyncThunk } from '@reduxjs/toolkit';
2
3export const userSlice = createSlice({
4  name: 'user',
5  initialState: {
6    username: '',
7    email: '',
8    isFetching: false,
9    isSuccess: false,
10    isError: false,
11    errorMessage: '',
12  },
13  reducers: {
14      // Reducer comes here
15  },
16  extraReducers: {
17       // Extra reducer comes here
18  },
19});
20
21export const userSelector = (state) => state.user;

Here, we use createSlice which handles the action and reducer in a single function. After that, add the reducer in redux store

app/store.js

1import { configureStore } from '@reduxjs/toolkit';
2import { userSlice } from '../features/User/UserSlice';
3export default configureStore({
4  reducer: {
5    user: userSlice.reducer,
6  },
7});

Once we create a basic structure for redux and store. it's time to create components for the application. Create Signup.js inside features/User directory,

1import React, { Fragment, useEffect } from 'react';
2import { Link } from 'react-router-dom';
3import { useForm } from 'react-hook-form';
4import { useSelector, useDispatch } from 'react-redux';
5import { signupUser, userSelector, clearState } from './UserSlice';
6import { useHistory } from 'react-router-dom';
7import toast from 'react-hot-toast';
8
9const Signup = () => {
10  const dispatch = useDispatch();
11  const { register, errors, handleSubmit } = useForm();
12  const history = useHistory();
13
14  const { isFetching, isSuccess, isError, errorMessage } = useSelector(
15    userSelector
16  );
17  const onSubmit = (data) => {
18    dispatch(signupUser(data));
19  };
20
21  useEffect(() => {
22    return () => {
23      dispatch(clearState());
24    };
25  }, []);
26
27  useEffect(() => {
28    if (isSuccess) {
29      dispatch(clearState());
30      history.push('/');
31    }
32
33    if (isError) {
34      toast.error(errorMessage);
35      dispatch(clearState());
36    }
37  }, [isSuccess, isError]);
38
39  return (
40    <Fragment>
41      <div className="min-h-screen bg-gray-50 flex flex-col justify-center py-12 sm:px-6 lg:px-8">
42        <div class="sm:mx-auto sm:w-full sm:max-w-md">
43          <h2 class="mt-6 text-center text-3xl font-extrabold text-gray-900">
44            Sign Up to your account
45          </h2>
46        </div>
47        <div className="mt-8 sm:mx-auto sm:w-full sm:max-w-md">
48          <div className="bg-white py-8 px-4 shadow sm:rounded-lg sm:px-10">
49            <form
50              className="space-y-6"
51              onSubmit={handleSubmit(onSubmit)}
52              method="POST"
53            >
54             {*/ Form Comes Here  */}
55            </form>
56            <div class="mt-6">
57              <div class="relative">
58                <div class="relative flex justify-center text-sm">
59                  <span class="px-2 bg-white text-gray-500">
60                    Or <Link to="login"> Login</Link>
61                  </span>
62                </div>
63              </div>
64            </div>
65          </div>
66        </div>
67      </div>
68    </Fragment>
69  );
70};
71
72export default Signup;

Here, we use React Hook Form to handle Form validation. Whenever we want to dispatch an action in redux, we use useDispatch provided by react-redux.

1const dispatch = useDispatch();

We can access redux state in component using hooks, useSelector

1const { isFetching, isSuccess, isError, errorMessage } = useSelector(
2    userSelector
3  );

Now, when an user submits a signup form, we need to dispatch an action by passing required data.

1const onSubmit = (data) => {
2    dispatch(signupUser(data));
3  };

Let's create that action in UserSlice.js

1export const signupUser = createAsyncThunk(
2  'users/signupUser',
3  async ({ name, email, password }, thunkAPI) => {
4    try {
5      const response = await fetch(
6        'https://mock-user-auth-server.herokuapp.com/api/v1/users',
7        {
8          method: 'POST',
9          headers: {
10            Accept: 'application/json',
11            'Content-Type': 'application/json',
12          },
13          body: JSON.stringify({
14            name,
15            email,
16            password,
17          }),
18        }
19      );
20      let data = await response.json();
21      console.log('data', data);
22
23      if (response.status === 200) {
24        localStorage.setItem('token', data.token);
25        return { ...data, username: name, email: email };
26      } else {
27        return thunkAPI.rejectWithValue(data);
28      }
29    } catch (e) {
30      console.log('Error', e.response.data);
31      return thunkAPI.rejectWithValue(e.response.data);
32    }
33  }
34);

Main purpose of using createAsyncThunk is it provides the API state out of the box. In traditional redux way, we need to handle the api state such as loading, success and failed.

createAsyncThunk provides us those states out of the box. To implement it, we just need to use the action name and the state of it.

Image Source

createAsyncThunk takes two argument,

Name that helps to identify action types.
A callback function that should return a promise

Further, callback function take two arguments. first, is the value that we pass from dispatched action and second argument is Thunk API config.

Once it returns a promise, either it will resolve or reject the promise. By default it provides us three state which are pending, fulfilled and rejected.

1extraReducers: {
2[signupUser.fulfilled]: (state, { payload }) => {
3      state.isFetching = false;
4      state.isSuccess = true;
5      state.email = payload.user.email;
6      state.username = payload.user.name;
7    },
8    [signupUser.pending]: (state) => {
9      state.isFetching = true;
10    },
11    [signupUser.rejected]: (state, { payload }) => {
12      state.isFetching = false;
13      state.isError = true;
14      state.errorMessage = payload.message;
15    }
16}

It updates the redux state which will update our component using hook useSelector. Once the signup successfully, it redirects to dashboard component.

1useEffect(() => {
2    if (isSuccess) {
3      dispatch(clearState());
4      history.push('/');
5    }
6
7    if (isError) {
8      toast.error(errorMessage);
9      dispatch(clearState());
10    }
11  }, [isSuccess, isError]);

Most of the logic will be similar to login workflow. create Login.js inside features/User directory and add the following code,

1import React, { Fragment, useEffect } from 'react';
2import { Link } from 'react-router-dom';
3import { useForm } from 'react-hook-form';
4import { useSelector, useDispatch } from 'react-redux';
5import { loginUser, userSelector, clearState } from './UserSlice';
6import toast from 'react-hot-toast';
7import { useHistory } from 'react-router-dom';
8
9const Login = ({}) => {
10  const dispatch = useDispatch();
11  const history = useHistory();
12  const { register, errors, handleSubmit } = useForm();
13  const { isFetching, isSuccess, isError, errorMessage } = useSelector(
14    userSelector
15  );
16  const onSubmit = (data) => {
17    dispatch(loginUser(data));
18  };
19
20  useEffect(() => {
21    return () => {
22      dispatch(clearState());
23    };
24  }, []);
25
26  useEffect(() => {
27    if (isError) {
28      toast.error(errorMessage);
29      dispatch(clearState());
30    }
31
32    if (isSuccess) {
33      dispatch(clearState());
34      history.push('/');
35    }
36  }, [isError, isSuccess]);
37
38  return (
39    <Fragment>
40      <div className="min-h-screen bg-gray-50 flex flex-col justify-center py-12 sm:px-6 lg:px-8">
41        <div class="sm:mx-auto sm:w-full sm:max-w-md">
42          <h2 class="mt-6 text-center text-3xl font-extrabold text-gray-900">
43            Sign in to your account
44          </h2>
45        </div>
46        <div className="mt-8 sm:mx-auto sm:w-full sm:max-w-md">
47          <div className="bg-white py-8 px-4 shadow sm:rounded-lg sm:px-10">
48            <form
49              className="space-y-6"
50              onSubmit={handleSubmit(onSubmit)}
51              method="POST"
52            >
53             {*/ Login Form Comes Here */}
54            </form>
55            <div class="mt-6">
56              <div class="relative">
57                <div class="relative flex justify-center text-sm">
58                  <span class="px-2 bg-white text-gray-500">
59                    Or <Link to="signup"> Signup</Link>
60                  </span>
61                </div>
62              </div>
63            </div>
64          </div>
65        </div>
66      </div>
67    </Fragment>
68  );
69};
70
71export default Login;

Here, we dispatch loginUser action which makes HTTP call in the redux slice.

1const onSubmit = (data) => {
2    dispatch(loginUser(data));
3  };

create an AsyncThunk function inside UserSlice.js and add the following code,

1export const loginUser = createAsyncThunk(
2  'users/login',
3  async ({ email, password }, thunkAPI) => {
4    try {
5      const response = await fetch(
6        'https://mock-user-auth-server.herokuapp.com/api/v1/auth',
7        {
8          method: 'POST',
9          headers: {
10            Accept: 'application/json',
11            'Content-Type': 'application/json',
12          },
13          body: JSON.stringify({
14            email,
15            password,
16          }),
17        }
18      );
19      let data = await response.json();
20      console.log('response', data);
21      if (response.status === 200) {
22        localStorage.setItem('token', data.token);
23        return data;
24      } else {
25        return thunkAPI.rejectWithValue(data);
26      }
27    } catch (e) {
28      console.log('Error', e.response.data);
29      thunkAPI.rejectWithValue(e.response.data);
30    }
31  }
32);

Promise will either be resolved or rejected based on HTTP call, let's handle it inside our reducer with the states,

1[loginUser.fulfilled]: (state, { payload }) => {
2      state.email = payload.email;
3      state.username = payload.name;
4      state.isFetching = false;
5      state.isSuccess = true;
6      return state;
7    },
8    [loginUser.rejected]: (state, { payload }) => {
9      console.log('payload', payload);
10      state.isFetching = false;
11      state.isError = true;
12      state.errorMessage = payload.message;
13    },
14    [loginUser.pending]: (state) => {
15      state.isFetching = true;
16    },

Once it updates our redux state, we will use it inside our component to render the result.

1const { isFetching, isSuccess, isError, errorMessage } = useSelector(
2    userSelector
3  );
4
5// Update UI based on the redux state(Success or Error)
6useEffect(() => {
7    if (isError) {
8      toast.error(errorMessage);
9      dispatch(clearState());
10    }
11
12    if (isSuccess) {
13      dispatch(clearState());
14      history.push('/');
15    }
16  }, [isError, isSuccess]);

Finally our Dashboard.js will be rendered with update user state from redux,

1import React, { Fragment, useEffect } from 'react';
2import { useSelector, useDispatch } from 'react-redux';
3import { userSelector, fetchUserBytoken, clearState } from './UserSlice';
4import Loader from 'react-loader-spinner';
5import { useHistory } from 'react-router-dom';
6
7const Dashboard = () => {
8  const history = useHistory();
9
10  const dispatch = useDispatch();
11  const { isFetching, isError } = useSelector(userSelector);
12  useEffect(() => {
13    dispatch(fetchUserBytoken({ token: localStorage.getItem('token') }));
14  }, []);
15
16  const { username, email } = useSelector(userSelector);
17
18  useEffect(() => {
19    if (isError) {
20      dispatch(clearState());
21      history.push('/login');
22    }
23  }, [isError]);
24
25  const onLogOut = () => {
26    localStorage.removeItem('token');
27
28    history.push('/login');
29  };
30
31  return (
32    <div className="container mx-auto">
33      {isFetching ? (
34        <Loader type="Puff" color="#00BFFF" height={100} width={100} />
35      ) : (
36        <Fragment>
37          <div className="container mx-auto">
38            Welcome back <h3>{username}</h3>
39          </div>
40
41          <button
42            onClick={onLogOut}
43            className="bg-red-500 hover:bg-red-700 text-white font-bold py-2 px-4 rounded"
44          >
45            Log Out
46          </button>
47        </Fragment>
48      )}
49    </div>
50  );
51};
52
53export default Dashboard;