Angular 4服务中的继承与注入

Question

I am a bit new to world of Angular. I am currently using Angular-4.4.6. My scenario is as follows: I have 3 components (for eg C1, C2, C3) each of which use their own services(eg S1, S2, S3 resp.) which then call "http.get()" to get the data from rest backend. What I want to know is instead of injecting the "http:HttpClient" in each of the three services, should I just create a 'RestService' class which has all the rest calls like get(), post(), put(), delete() and then:

• extend this base class into each of my 3 services where I will subscribe to these method calls of base class and then use the data fetched?

OR

• inject the 'RestService' which has generic methods into constructor of each of my services and then use these services by subscribing them?

Are there any performance hits with these two approaches?

Answer 1

I like to have a "base service"

export class ServiceModel<T>{
    type: string;
    url: string;
    ...
    constructor(private _http: HttpClient) {
    }
    list(): Observable<T[]> {
        return this._http.get<T[]>(this.url)
    }
    ...
}

Then in data1Service

export interface IData1
{
    id:number;
    desc:string;
    ...
}

@Injectable()
export class Data1Service extends ServiceModel<IData1> {
    type:string="data1";
    url:string="myurl/data1";

    constructor(http: HttpClient) {
        super(http)
    }
}

But I don't kwon if this answer resolve your question :(