Using Angular 7 & Typescript: I have a base class that uses a lot of services and child classes (about 40 sub-class) and I don't want to add those services in all subclass constructor and pass them to super() but I still need to use those services in all subclass.
export class parentTool {
constructor(type: string, public service1: Service1, public service2: Service2,public service3: Service3, public service4: Service4){}
}
export class ChildTool1 extends parentTool {
constructor(public service1: Service1, public service2: Service2,public service3: Service3, public service4: Service4) {
super("tool1", service1, service2, service3, service4);
}
}
export class ChildTool2 extends parentTool {
constructor(public service1: Service1, public service2: Service2,public service3: Service3, public service4: Service4) {
super("tool2", service1, service2, service3, service4);
}
}
I use to have the same problem so I end up doing manulay DI (dependency injection) by using injector service
this static class use to store a refrence of injector service
export class AppInjector {
private static injector: Injector;
static setInjector(injector: Injector) {
AppInjector.injector = injector;
}
static getInjector(): Injector {
return AppInjector.injector;
}
}
at app module I set the injoctor service
export class AppModule {
constructor(injector:Injector){
AppInjector.setInjector(injector);// save a injector ref 💾
}
}
you need to store the service before you start do any DI (dependency injection)
in the base component
export class BaseComponent {
protected utilitiesService: UtilitiesService; // 👈 service
protected loggingService: LoggingService; // 👈 service
constructor() {
const injector = AppInjector.getInjector();
this.utilitiesService = injector.get(UtilitiesService); // 🌟 DI
this.loggingService = injector.get(LoggingService); // 🌟 DI
}
}
child class now have access to all service injected by the injector class 🎉🎉
export class ChildComponent extends BaseComponent {
constructor() {
super();
}
}