Angularjs Handling Refresh Token

Handling refresh tokens in AngularJS is an essential aspect of building secure and robust applications. A refresh token allows you to obtain a new access token once it expires without requiring the user to log in again. In this guide, we'll walk you through the process of integrating refresh token functionality into your AngularJS application.

First and foremost, you need to understand the fundamental concept behind refresh tokens. When a user logs into your application, they are issued an access token that grants them access to protected resources. This access token has a limited lifespan, typically ranging from a few minutes to hours. Once it expires, the user would typically need to log in again. However, by using a refresh token, you can obtain a new access token without disrupting the user experience.

To implement refresh token functionality in your AngularJS application, you first need to ensure that your backend API supports issuing and validating refresh tokens. This involves generating a refresh token when a user logs in and storing it securely on the client-side.

Next, you'll need to set up an interceptor in AngularJS to automatically send the refresh token to the server when the access token expires. This interceptor will intercept outgoing HTTP requests, detect when an access token is expired, and initiate the token refresh process.

Here's a basic structure of how you can set up the interceptor in AngularJS:

app.factory('AuthInterceptor', function ($rootScope, $q, AuthService) {
  return {
    request: function (config) {
      if (AuthService.isAccessTokenExpired()) {
        return AuthService.refreshToken().then(function () {
          config.headers.Authorization = 'Bearer ' + AuthService.getAccessToken();
          return config;
        });
      } else {
        return config;
      }
    }
  };
});

app.config(function ($httpProvider) {
  $httpProvider.interceptors.push('AuthInterceptor');
});

In this code snippet, we define an `AuthInterceptor` factory that checks if the access token is expired. If it is, the interceptor calls the `refreshToken()` method from the `AuthService` service, updates the request headers with the new access token, and proceeds with the request. Make sure to replace `AuthService` with your actual authentication service.

Finally, don't forget to handle token refresh failures gracefully. If the refresh token is invalid or expired, you may need to log the user out and prompt them to log in again.

By implementing refresh token functionality in your AngularJS application, you can provide users with a seamless and secure authentication experience. Remember to keep your refresh tokens secure and handle token expiration scenarios effectively to ensure the integrity of your application's authentication process.