Authentication and Authorization in Vue.js: Techniques and Libraries
Published: 2023-12-29 11:38:19

To ensure that your web apps are secure, you have to implement authentication and authorization protocols. To do that, you need a framework that can provide a robust environment that can implement these features seamlessly. And VueJS is just the right framework that checks all those boxes. 

This article discusses the processes of authentication and authorization process implementation in a VueJS app.

## VueJS Authentication
The authentication process in the VueJS app allows you to identify the identity of the users. We will provide a step-by-step process for implementing the authentication process in your VueJS application.
 
### Step 1: Building the Login Component
The Login Component is the one that gathers email, password, and other user credentials. Vue Routers are used to manage the routing in an app. After the login is successful, the authentication tokens like JWT are stored in the local storage of the web browser.
```<template>
 <div> 
   <input type="email" v-model="email" placeholder="Email">
   <input type="password" v-model="password" placeholder="Password">
   <button @click="login">Login</button>
 </div>
</template>

<script>
export default {
 data() {
   return {
     email: '',
     password: ''
   };
 },
 methods: {
   login() {
     // Send login request and handle authentication token
     // Store token in local storage
   }
 }
};
</script>
```
### Step 2: Protecting Routes
The use of certain routes has to be restricted and only authenticated users can access them. To accomplish that, we have to use Vue Router to place route guards on those specific routes. Before being navigated to the secure routes, the execution of guards should be carried out. 

```
import Vue from 'vue';
import VueRouter from 'vue-router';

Vue.use(VueRouter);

const router = new VueRouter({
 routes: [
   {
     path: '/dashboard',
     component: Dashboard,
     meta: {
       requiresAuth: true // Add meta field to indicate protected route
     }
   },
   // Other routes...
 ]
});

router.beforeEach((to, from, next) => {
 if (to.meta.requiresAuth) {
   const token = localStorage.getItem('token');
   if (token) {
     // User is authenticated, proceed to the route
     next();
   } else {
     // User is not authenticated, redirect to login
     next('/login');
   }
 } else {
   // Non-protected route, allow access
   next();
 }
});
   export default router;
```

## Authorization with VueJS 
Authorization defines what resources or actions based on their permissions or roles a user can access. Here is the process of implementing VueJS authorization: 

### Step 1: Role-Based Authorization
You have to assign different roles to the users such as a user, editor, or admin. The features and components would be provided according to the users’ roles based on specific conditions. 

```
<template>
 <div>
   <h1>Welcome, {{ username }}</h1>
   <div v-if="isAdmin">
     <!-- Render admin-specific features -->
   </div>
   <div v-else>
     <!-- Render user-specific features -->
   </div>
 </div>
</template>

<script>
export default {
 computed: {
   username() {
     // Get username from authentication state
   },
   isAdmin() {
     // Check if user has admin role
   }
 }
};
</script>
```

### Step 2: Server-Side Authorization
It is important to make sure that the specific API endpoints are protected with server-side checks that are only accessible to authorized users. Before the requested data is served to the users, their permissions, or roles are validated along with their authentication token. 

```
// Example using Express.js middleware
app.get('/admin-data', verifyToken, (req, res) => {
 if (req.user.role === 'admin') {
   // Serve admin-specific data
 } else {
   // User is not authorized, send appropriate response
 }
});
```

## Conclusion
To maintain secure access control over your VueJS application, you have to implement both authentication and authorization processes effectively. The steps shown in this article can help you implement a robust authorization and authentication system on your Vue app with the help of features such as computed properties and Vue Router. 

Do not forget to use the route guards for the protection of the routes. They are the components that are rendered conditionally based on the user roles and conduct the authorization checks on the server side. Vue offers all the tools you would need to make your web app secure and user-friendly.