Redirect To Keycloak Self-Registration Form With Angular Auth OIDC Client

Jul 16, 2025 by Jeany 74 views

Redirecting to Keycloak Self-Registration Form with Angular Auth OIDC Client

In this comprehensive guide, we'll delve into the intricacies of redirecting users to Keycloak's self-registration form using the angular-auth-oidc-client library. This is a crucial aspect of modern application development, particularly when you want to empower users to create their accounts seamlessly. We will address the challenges, provide step-by-step solutions, and explore best practices for implementing this functionality.

Understanding the Need for Self-Registration

Self-registration is an indispensable feature for applications aiming for a broad user base. It eliminates the friction associated with manual account creation by administrators and allows users to sign up independently. Keycloak, a leading open-source Identity and Access Management solution, provides robust support for self-registration, making it an ideal choice for securing modern applications. By integrating Keycloak's self-registration capabilities with Angular-based frontends, developers can create user-friendly and secure registration workflows.

Prerequisites

Before we dive into the implementation details, let's ensure we have the necessary prerequisites in place:

Keycloak Server: You need a running Keycloak instance with self-registration enabled for your realm. Verify that the self-registration flow is correctly configured within Keycloak's administration console.
Angular Project: An existing Angular project integrated with the angular-auth-oidc-client library. This library simplifies the integration of OpenID Connect (OIDC) authentication flows within Angular applications.
angular-auth-oidc-client: Ensure you have the latest version (v19 or later) of the angular-auth-oidc-client library installed in your Angular project. This version offers enhanced features and compatibility with modern Keycloak versions.

The Challenge: Directing Users to the Registration Form

The core challenge we address here is how to create a button or link within your Angular application that directly redirects users to Keycloak's self-registration form. While the angular-auth-oidc-client library provides methods for initiating authentication flows, directly navigating to the registration form requires a specific approach. Many developers encounter difficulties in crafting the correct URL and ensuring a seamless transition for the user.

Step-by-Step Solution: Constructing the Registration URL

To achieve the desired redirection, we need to construct the appropriate URL for Keycloak's registration endpoint. This URL typically includes the Keycloak server address, realm name, and the kc_action=register parameter. Let's break down the process:

1. Obtain Keycloak Configuration

First, you need to retrieve the Keycloak configuration, which usually includes the authorization endpoint URL. The angular-auth-oidc-client library provides a way to access this configuration.

import { OidcSecurityService, AuthorizationResult, AuthorizationState } from 'angular-auth-oidc-client';
import { Component, OnInit } from '@angular/core';

@Component({
 selector: 'app-register',
 templateUrl: './register.component.html',
 styleUrls: ['./register.component.scss']
})
export class RegisterComponent implements OnInit {
 constructor(private oidcSecurityService: OidcSecurityService) {}

 ngOnInit() {
 this.oidcSecurityService.configurationLoaded$.subscribe((configLoaded) => {
 if (configLoaded) {
 console.log('Configuration loaded');
 }
 });
 }

 public redirectToKeycloakRegistration() {
 this.oidcSecurityService.getConfiguration().subscribe((config) => {
 const registrationUrl = `${config.stsServer}/realms/${config.realm}/protocol/openid-connect/auth?client_id=${config.clientId}&response_type=code&scope=openid profile email&redirect_uri=${config.redirectUrl}&kc_action=register`;
 window.location.href = registrationUrl;
 });
 }
}

2. Construct the Registration URL

Using the retrieved configuration, we construct the registration URL. This URL should include the following components:

stsServer: The base URL of your Keycloak server.
realm: The name of your Keycloak realm.
client_id: The client ID of your Angular application.
redirect_uri: The URL to which Keycloak will redirect the user after registration (usually your application's callback URL).
kc_action=register: This parameter tells Keycloak to display the registration form.

3. Redirect the User

Finally, we use window.location.href to redirect the user to the constructed registration URL.

Code Implementation

Here's a complete example of how you can implement this in your Angular component:

import { OidcSecurityService } from 'angular-auth-oidc-client';
import { Component, OnInit } from '@angular/core';

@Component({
 selector: 'app-register',
 templateUrl: './register.component.html',
 styleUrls: ['./register.component.scss']
})
export class RegisterComponent implements OnInit {
 constructor(private oidcSecurityService: OidcSecurityService) {}

 ngOnInit() {}

 public redirectToKeycloakRegistration() {
 this.oidcSecurityService.getAuthorizeUrl({ customParams: { kc_action: 'register' } }).subscribe((url) => {
 window.location.href = url;
 });
 }
}

And in your HTML template:

<button (click)="redirectToKeycloakRegistration()">Register</button>

Explanation

We inject the OidcSecurityService into our component.
The redirectToKeycloakRegistration method constructs the registration URL using the Keycloak configuration.
We use window.location.href to redirect the user to the Keycloak registration page.

Handling the Redirection

After the user completes the registration process on Keycloak, they will be redirected back to your application. The redirect_uri parameter in the registration URL determines the destination. Your application should be prepared to handle this redirection and potentially initiate the login flow.

Best Practices and Considerations

1. Security

Always ensure that your redirect_uri is properly configured and validated to prevent unauthorized redirects. In Keycloak, you can configure valid redirect URIs for your client.

2. Error Handling

Implement robust error handling to gracefully manage scenarios where the Keycloak server is unavailable or the registration process fails.

3. User Experience

Provide clear feedback to the user during the redirection process. Display a message indicating that they are being redirected to the registration page.

4. Customization

Keycloak allows you to customize the registration form. You can add custom fields and modify the appearance to match your application's branding.

5. Testing

Thoroughly test the registration flow in various scenarios to ensure it works as expected. Test with different browsers and devices.

Troubleshooting Common Issues

1. Invalid Redirect URI

If you encounter an "Invalid redirect URI" error, double-check that the redirect_uri in your registration URL matches the configured redirect URIs in Keycloak.

2. Keycloak Server Unavailable

If the Keycloak server is unavailable, your application may not be able to construct the registration URL. Implement error handling to display an appropriate message to the user.

3. CORS Issues

Cross-Origin Resource Sharing (CORS) issues can prevent your application from retrieving the Keycloak configuration. Ensure that CORS is properly configured on your Keycloak server.

Advanced Scenarios

1. Pre-filling Registration Fields

In some cases, you may want to pre-fill certain fields in the registration form. You can achieve this by adding additional parameters to the registration URL. However, be cautious about security implications and avoid pre-filling sensitive information.

2. Custom Registration Flows

Keycloak allows you to define custom registration flows using authentication flows. This gives you fine-grained control over the registration process.

Conclusion

Redirecting users to Keycloak's self-registration form using the angular-auth-oidc-client library is a straightforward process when you understand the underlying mechanisms. By constructing the correct registration URL and handling the redirection appropriately, you can create a seamless user experience. Remember to follow best practices for security, error handling, and user experience to ensure a robust and user-friendly registration flow.

This comprehensive guide has equipped you with the knowledge and code examples necessary to implement this functionality in your Angular applications. By leveraging the power of Keycloak and the angular-auth-oidc-client library, you can build secure and scalable applications with ease.