Vue Refresh Token with Axios and JWT example

With previous posts, we’ve known how to build Authentication and Authorization in a Vue Vuex Application. In this tutorial, I will continue to show you way to implement Vue Refresh Token with Axios Interceptors and JWT.

Related Posts:
– Axios Interceptors tutorial with Refresh Token example
– In-depth Introduction to JWT-JSON Web Token
– Vue.js JWT Authentication with Vuex and Vue Router

Vue 3 version: Vue 3 Refresh Token with Axios and JWT example

Vue Refresh Token overview

The diagram shows flow of how we implement Vue.js JWT Refresh Token with Axios.

– A refreshToken will be provided at the time user signs in.
– A legal JWT must be added to HTTP Header if Client accesses protected resources.
– With the help of Axios Interceptors, Vue App can check if the accessToken (JWT) is expired (401), sends /refreshToken request to receive new accessToken and use it for new resource request.

Let’s see how the Vue Refresh Token example works with demo UI.

– User makes an account login first.

– Then user can access resources with available Access Token.

– When the Access Token is expired, Vue App automatically send Refresh Token request, receive new Access Token and use it with new request.

So the server still accepts resource access from the user.

– After a period of time, the new Access Token is expired again, and the Refresh Token too.

The Back-end server for this Vue.js Client can be found at:

• Spring Boot JWT Refresh Token example
• Node.js JWT Refresh Token example with MySQL/PostgreSQL
• Node.js JWT Refresh Token example with MongoDB

We’re gonna implement Token Refresh feature basing on the code from previous posts, so you need to read following tutorial first:
Vue.js JWT Authentication with Vuex and Vue Router

Vuex with Refresh Token

Now we need to add a Vuex action and a mutation – refreshToken.

store/auth.module.js

import AuthService from '../services/auth.service';

const user = JSON.parse(localStorage.getItem('user'));
const initialState = user
  ? { status: { loggedIn: true }, user }
  : { status: { loggedIn: false }, user: null };

export const auth = {
  namespaced: true,
  state: initialState,
  actions: {
    ...
    refreshToken({ commit }, accessToken) {
      commit('refreshToken', accessToken);
    }
  },
  mutations: {
    ...
    refreshToken(state, accessToken) {
      state.status.loggedIn = true;
      state.user = { ...state.user, accessToken: accessToken };
    }
  }
};

Axios interceptors in Vue App

Let’s create a service that provides an Axios instance.

services/api.js

import axios from "axios";

const instance = axios.create({
  baseURL: "http://localhost:8080/api",
  headers: {
    "Content-Type": "application/json",
  },
});

export default instance;

Then we’re gonna create a setupInterceptors() function with interceptors request and dispatch the Vuex action for refresh token in the response.

services/setupInterceptors.js

import axiosInstance from "./api";
import TokenService from "./token.service";

const setup = (store) => {
  axiosInstance.interceptors.request.use(
    (config) => {
      const token = TokenService.getLocalAccessToken();
      if (token) {
        // config.headers["Authorization"] = 'Bearer ' + token;  // for Spring Boot back-end
        config.headers["x-access-token"] = token; // for Node.js Express back-end
      }
      return config;
    },
    (error) => {
      return Promise.reject(error);
    }
  );

  axiosInstance.interceptors.response.use(
    (res) => {
      return res;
    },
    async (err) => {
      const originalConfig = err.config;

      if (originalConfig.url !== "/auth/signin" && err.response) {
        // Access Token was expired
        if (err.response.status === 401 && !originalConfig._retry) {
          originalConfig._retry = true;

          try {
            const rs = await axiosInstance.post("/auth/refreshtoken", {
              refreshToken: TokenService.getLocalRefreshToken(),
            });

            const { accessToken } = rs.data;

            store.dispatch('auth/refreshToken', accessToken);
            TokenService.updateLocalAccessToken(accessToken);

            return axiosInstance(originalConfig);
          } catch (_error) {
            return Promise.reject(_error);
          }
        }
      }

      return Promise.reject(err);
    }
  );
};

export default setup;

In the code above, we:
– intercept requests or responses before they are handled by then or catch.
– handle 401 status on interceptor response (without response of login request).
– use a flag call _retry on original Request (config) to handle Infinite loop. It is the case that request is failed again, and the server continue to return 401 status code.

For more details, please visit:
Axios Interceptors tutorial with Refresh Token example

Let’s import the setupInterceptors() function in main.js where we can pass the Vuex store.

src/main.js

import Vue from 'vue';
import App from './App.vue';
import { router } from './router';
import store from './store';
import Vuex from 'vuex';
...
import setupInterceptors from './services/setupInterceptors';

Vue.use(Vuex);

setupInterceptors(store);

new Vue({
  router,
  store,
  render: h => h(App)
}).$mount('#app');

Update Services with new Axios Interceptors

Axios Interceptors manipulate the header, body, parameters of the requests sent to the server so that we don’t need to add headers in Axios requests like this:

axios.get(API_URL, { headers: authHeader() })

So we remove auth-header.js file, then update services that use it with new api service.

services/user.service.js

import api from './api';

class UserService {
  getPublicContent() {
    return api.get('/test/all');
  }

  getUserBoard() {
    return api.get('/test/user');
  }

  getModeratorBoard() {
    return api.get('/test/mod');
  }

  getAdminBoard() {
    return api.get('/test/admin');
  }
}

export default new UserService();

services/auth.service.js

import api from "./api";
import TokenService from "./token.service";

class AuthService {
  login({ username, password }) {
    return api
      .post("/auth/signin", {
        username,
        password
      })
      .then((response) => {
        if (response.data.accessToken) {
          TokenService.setUser(response.data);
        }

        return response.data;
      });
  }

  logout() {
    TokenService.removeUser();
  }

  register({ username, email, password }) {
    return api.post("/auth/signup", {
      username,
      email,
      password
    });
  }
}

export default new AuthService();

We also need to create TokenService which Axios instance and other services use above.
TokenService provides get, set, remove methods to work with Token and User Data stored on Browser.

services/token.service.js

class TokenService {
  getLocalRefreshToken() {
    const user = JSON.parse(localStorage.getItem("user"));
    return user?.refreshToken;
  }

  getLocalAccessToken() {
    const user = JSON.parse(localStorage.getItem("user"));
    return user?.accessToken;
  }

  updateLocalAccessToken(token) {
    let user = JSON.parse(localStorage.getItem("user"));
    user.accessToken = token;
    localStorage.setItem("user", JSON.stringify(user));
  }

  getUser() {
    return JSON.parse(localStorage.getItem("user"));
  }

  setUser(user) {
    console.log(JSON.stringify(user));
    localStorage.setItem("user", JSON.stringify(user));
  }

  removeUser() {
    localStorage.removeItem("user");
  }
}

export default new TokenService();

Handle expired Token in Vue

When both Access Token and Refresh Token are expired, we need to logout the user. How to do it? We read response status from the server, then dispatch logout event to App component when the response status tells us the JWT token is expired.

First we need to set up a global event-driven system, or a PubSub system, which allows us to listen and dispatch events from independent components.

An Event Bus implements the PubSub pattern, events will be fired from other components so that they don’t have direct dependencies between each other.

We’re gonna create Event Bus with three methods: on, dispatch, and remove.

common/EventBus.js

const eventBus = {
  on(event, callback) {
    document.addEventListener(event, (e) => callback(e.detail));
  },
  dispatch(event, data) {
    document.dispatchEvent(new CustomEvent(event, { detail: data }));
  },
  remove(event, callback) {
    document.removeEventListener(event, callback);
  },
};

export default eventBus;

– on() method attachs an EventListener to the document object. The callback will be called when the event gets fired.
– dispatch() method fires an event using the CustomEvent API.
– remove() method removes the attached event from the document object.

Next we import EventBus in App component and listen to "logout" event.

src/App.vue

<template>
  ..
</template>

<script>
import EventBus from "./common/EventBus";

export default {
  computed: {
    ..
  },
  methods: {
    logOut() {
      this.$store.dispatch('auth/logout');
      this.$router.push('/login');
    }
  },
  mounted() {
    EventBus.on("logout", () => {
      this.logOut();
    });
  },
  beforeDestroy() {
    EventBus.remove("logout");
  }
};
</script>

Finally we only need to dispatch "logout" event in the components when getting Unauthorized response status.

components/BoardUser.js

<template>
  ..
</template>

<script>
import UserService from '../services/user.service';
import EventBus from "../common/EventBus";

export default {
  name: 'User',
  ...
  mounted() {
    UserService.getUserBoard().then(
      response => { ... },
      error => {
        this.content =
          (error.response && error.response.data && error.response.data.message) ||
          error.message ||
          error.toString();

        if (error.response && error.response.status === 403) {
          EventBus.dispatch("logout");
        }
      }
    );
  }
};
</script>

Conclusion

Today we know how to implement JWT Refresh Token into a Vue Vuex Application using Axios Interceptors. For your understanding the logic flow, you should read one of following tutorial first:
Vue.js JWT Authentication with Vuex and Vue Router

The Back-end server for this Vue Client can be found at:

• Spring Boot JWT Refresh Token example
• Node.js JWT Refresh Token example with MySQL/PostgreSQL
• Node.js JWT Refresh Token example with MongoDB

Further Reading

Related Posts:
– In-depth Introduction to JWT-JSON Web Token
– Axios Interceptors tutorial with Refresh Token example

Fullstack Authentication & Authorization:
– Vue + Spring Boot
– Vue + Node.js Express

Source Code

The source code for this React Application can be found at Github.

Vue 3 version: Vue 3 Refresh Token with Axios and JWT example