In Angular2, Use Service to get application routes - angular6

Question

I have angular 6 application. I have requirements to get dynamic routes, logic of which is been sorted. I have AppRoutingService class which has method getAppRoutes() returning static route collection. I need this to be called app RouterModule.forRoot(...), the objective if can manage to inject static routes using service class, then I can assemble dynamic routes from database in this static list.
In doing so I am getting error.
error
Uncaught TypeError: Cannot read property 'appRoutingService' of undefined
at main.js:1055
at Module../src/app/modules/application/app-routing.module.ts (main.js:1065)
at __webpack_require__ (runtime.js:84)
App routing class
import { AppRoutingService } from './services/routing/app-routing-service';
#NgModule({
imports: [
RouterModule.forRoot(this.appRoutingService.getAppRoutes()) // here i need to inject appRoutingService method... need help here....???
],
exports: [
RouterModule
]
})
export class AppRoutingModule {
constructor(
private router:Router,
private appRoutingService: AppRoutingService
) {
}
}
App Routing Service class
#Injectable()
export class AppRoutingService{
public RouteCollection: Routes = [
{
path:'',
redirectTo: 'dashboard',
pathMatch: 'full'
},
{
path: '',
component: WebLayoutComponent,
children:[
{
path:'dashboard',
loadChildren: '../dashboard/dashboard.module#DashboardModule'
},
{
path:'survey',
loadChildren: '../survey/survey.module#SurveyModule'
}
]
},
{
path:'**',
component:PageNotFoundComponent
}
];
public getAppRoutes(): Route[]
{
return this.RouteCollection;
}
}

Answer 1

You are using the keyword "this" in a wrong place. there is no "this" in that context, because it is outside of a class. Since "this" === undefined, then the reason behind the error becomes clear, because you are trying to fetch the appRoutingService from undefined.
#NgModule({
imports: [
RouterModule.forRoot(AppRoutingService.getAppRoutes()) // here i need
to inject appRoutingService method... need help here....???
],
exports: [
RouterModule
]
})
And make the AppRoutingService method and variable static.
public static RouteCollection: Routes = [
{
path:'',
redirectTo: 'dashboard',
pathMatch: 'full'
},
{
path: '',
component: WebLayoutComponent,
children:[
{
path:'dashboard',
loadChildren: '../dashboard/dashboard.module#DashboardModule'
},
{
path:'survey',
loadChildren: '../survey/survey.module#SurveyModule'
}
]
},
{
path:'**',
component:PageNotFoundComponent
}
];
public static getAppRoutes(): Route[]
{
return AppRoutingService.RouteCollection;
}