Ui-router Considerations in AngularJS Authentication

Navigating between different sections of an application while implementing login authentication can be a challenge when using AngularJS ui-router. Here's how to handle this scenario:

Defining User Identity

Create a service called principal to manage user identity. It should be able to determine if a user is authenticated, retrieve essential user information (e.g., display name, username), and perform role checks.

Authorization

Implement an authorization service that uses the principal service to check if a user is authorized to access a specific state. If not, it redirects unauthenticated users to a sign-in page or unauthorized users to an access denied page.

Ui-router Event Listener

Listen for the $stateChangeStart event in ui-router. Within this event, use the authorization service to check authorization for the intended destination state. If authorization fails, cancel the state transition or redirect to an appropriate page.

Resolving User Identity

Before authorization checks, the user's identity must be resolved. Define a parent state in ui-router with a resolve property that calls the authorization service's authorize function. This ensures that identity resolutions occur before any state changes.

Conditional Rendering

Use the principal service in views to conditionally render elements or templates based on the user's authentication status or role. For instance, you can show/hide components using directives like ng-show or ng-hide.

Home Page and Dashboard

In your sample application, configure a state for the home page that allows unauthenticated users access. Add links or forms for sign-in or sign-up. Create a separate state for the dashboard and define it as a child of a parent state that requires authentication.