在Observables（angular2）中处理数据的模式是什么

Question

suppose we have this service

@Injectable()
export class CarService {  

    constructor (private http: Http) {}

    getCars() { 
        return this.http.get('someurl')
                .map(res => <Car[]> res.json())               
                .catch(this.handleError);  
    }   
}

and we subscribe to this in another component. If Car looks like this:

class Car{
   Color:string;
   Timestamp:any; //this comes as a string in JSON but I want it to be of type Date object
}

and we want to have some logic, ie change date:string to date type, where should this be done?

in a service? and how? in a class itself? will .map() hit the constructor of Car class?

Answer 1

I would put this process either:

• in a map operator that leverages the map method of arrays

   return this.http.get('someurl') .map(res => <Car[]> res.json()) .map(data => { data.map((d) => { var date = (...) return new Car(color, date); }); return data; }) .catch(this.handleError); 

• in the constructor of the Car class

   return this.http.get('someurl') .map(res => <Car[]> res.json()) .map(data => { data.map((d) => { return new Car(color, timestampAsString); }); return data; }) .catch(this.handleError);