`inject()` khác constructor injection thế nào?

Constructor injection khai báo dependency qua constructor parameters, rõ ràng và quen thuộc.

Ví dụ functional guard dùng inject():

export const authGuard: CanActivateFn = () => {
  const auth = inject(AuthService)
  const router = inject(Router)

  return auth.isLoggedIn() ? true : router.createUrlTree(["/login"])
}

inject() gọn hơn cho guards, resolvers, interceptors hoặc field initializers; chỉ gọi trong injection context hợp lệ.

Constructor injection declares dependencies through constructor parameters and is explicit and familiar.

Example functional guard using inject():

export const authGuard: CanActivateFn = () => {
  const auth = inject(AuthService)
  const router = inject(Router)

  return auth.isLoggedIn() ? true : router.createUrlTree(["/login"])
}

inject() is convenient for guards, resolvers, interceptors or field initializers; call it only in a valid injection context.