What are Auth Guards in Angular?

What are Auth Guards in Angular?

In Angular, Auth Guards are used to protecting routes and prevent unauthorized access to certain parts of an application. Auth Guards are implemented as services that can be registered with the Angular dependency injection system and added to the routing configuration.

When a user tries to navigate to a protected route, the Auth Guard checks whether the user is authenticated and authorized to access the route. If the user is authenticated and authorized, the Auth Guard allows the user to navigate to the route. Otherwise, the Auth Guard redirects the user to a login page or displays an error message.

There are two types of Auth Guards in Angular:

CanActivate: This guard is used to prevent unauthorized access to a route. It is called when the user tries to navigate to a route and checks whether the user is authorized to access the route.

CanActivateChild: This guard is used to prevent unauthorized access to child routes. It is called when the user tries to navigate to a child route and checks whether the user is authorized to access the child route.

To create an Auth Guard in Angular, you need to implement the CanActivate or CanActivateChild interface and define the canActivate or canActivateChild method respectively. These methods return a boolean or a Promise/Observable that resolves to a boolean, indicating whether the user is authorized to access the route.

Once you have created an Auth Guard, you can register it with the routing configuration by adding it to the canActivate or canActivateChild property of the route. For example:

const routes: Routes = [
  {
    path: 'protected',
    component: ProtectedComponent,
    canActivate: [AuthGuard]
  }
];

In this example, AuthGuard is registered as the guard for the protected route, which means that the user needs to be authorized to access the ProtectedComponent. Overall, Auth Guards provide a way to protect routes and prevent unauthorized access to certain parts of an application. They can be used in conjunction with other Angular features like authentication services and interceptors to provide a secure and seamless user experience.