Angular 2 - Typescript Basic Test-Database Class

Question

I am learning Angular 2 and playing around with a sandbox project, and was wondering how to use a class in another class similar to how you would in Java or other OOP languages.

If i have a class MockDatabase like so:

export class MockDatabase {


constructor(private list: Restaurant[]){
    this.list.push({ id: 1, name: "Chinese", tags: ["Chinese"] });
    this.list.push({ id: 2, name: "Mexican", tags: ["Mexican"] });
    this.list.push({ id: 3, name: "Italian", tags: ["Italian"] });
    this.list.push({ id: 4, name: "American", tags: ["American"] });

}

getList(): Restaurant[] {
    return this.list;
}
}

and I want to use that class in a service class like so:

@Injectable()
export class RestaurantsService {


constructor(private db: MockDatabase){

}

getAllRestaurants(): Restaurant[] {
    return this.db.getList();
}


}

which is then used in this component:

@Component({
  selector: 'restaurants',
  templateUrl: 'restaurants.html',
  providers: [RestaurantsService, PreferencesFilterService]
})
export class RestaurantsComponent implements OnInit{

restaurants: Restaurant[];

constructor(
  private restaurantsService: RestaurantsService,
  private preferencesFilterService: PreferencesFilterService
) {}

ngOnInit(): void {
  this.restaurants = this.restaurantsService.getAllRestaurants();
}

filterRestaurants(): void {
  this.restaurants = this.preferencesFilterService.getFilteredRestaurants();
}

I get an error saying "No provider for MockDatabase," but then if I add it as a provider to the RestaurantsComponent I get another error saying "No provider for Array()," so I think I am doing something wrong here.

I believe I may have a fundamental misunderstanding of the way you are supposed to design things like this in Angular 2 as I am brand new to web development as a whole.

Any help or pointers in the right direction would be greatly appreciated, as i was having trouble finding a good resource online. Thank you very much for your time.

Angular 2 - Typescript Basic Test-Database Class

1 Answers