Executing a service prior to the loading of Angular 7 applications or components

Currently, I am in the process of developing an application using Angular 7. So far, everything is running smoothly as I have successfully managed API calls, JWT Token authentication with C#, and updating LocalStorage when needed during user login and logout.

However, I am facing a dilemma regarding setting up a middleware for login check within the application rather than relying on the lifecycle method - ng.onInit(). How can I accomplish this?

I am also curious if there is a way to trigger lifecycle events through an entry component or service. This would allow the application to verify the user's login status before loading any components and redirecting appropriately via Router.

Answer №1

When it comes to securing your application, Guard relies on the routes for protection. In my opinion, opting for a module/service solution would be more beneficial.

import { APP_INITIALIZER } from '@angular/core';

To implement this solution, you can follow these steps:


export function initializeApp(initializeService: YourInitializeService) {
  return () => { 
    initializeService.Initialize();
  }
}

{ provide: APP_INITIALIZER, useFactory: initializeApp, deps: [YourInitializeService], multi: true }

Answer №2

If you're working with Angular, don't forget to utilize Guard functionalities, especially canActivate Guard. Check out this helpful link for more information: https://angular.io/guide/router

To create a guard, follow this structure:

@Injectable({
  providedIn: 'root'
})
export class MyGuard implements CanLoad {
 constructor() {}

 canLoad(route: Route, segments: UrlSegment[]): Observable<boolean> | 
 Promise<boolean> | boolean {
   const x = true;
   if (x) {
     return true; // Allows access to the route
   } else {
      // Redirect as needed
     return false; // Prevents access to the route
  }
 }
}

In your routing Module, include the guard like so:

{
path: "yourRoute",
canActivate: [MyGuard],
component: YourComponent
}

For authentication needs, consider using a reliable library like ngx-auth which works seamlessly with guards: https://www.npmjs.com/package/ngx-auth

Answer №3

To enhance the security of your routing in Angular, consider incorporating an authGuardService as a middleware using the canActivate section.

For more information, refer to: https://angular.io/api/router/CanActivate

By doing so, you can prevent routes from being accessed if the conditions set by the canActivate service are not met. This is particularly useful for implementing login systems and ensuring access control without relying solely on lifecycle hooks.

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