I'm currently working on the Nativescript/Angular tutorial and I stumbled upon a particular piece of code that has left me puzzled. In chapter 4 (Nativescript modules), there is a section where they make an http.get request to fetch the Grocery List and then apply some map operators to the Observable. Here is the snippet of code:
import { Injectable } from "@angular/core";
import { Http, Headers } from "@angular/http";
import { Observable } from "rxjs/Rx";
import "rxjs/add/operator/map";
import { Config } from "../config";
import { Grocery } from "./grocery";
@Injectable()
export class GroceryListService {
constructor(private http: Http) {}
load() {
let headers = new Headers();
headers.append("Authorization", "Bearer " + Config.token);
return this.http.get(Config.apiUrl + "Groceries", {
headers: headers
})
.map(res => res.json())
.map(data => {
let groceryList = [];
data.Result.forEach((grocery) => { //<------HERE
groceryList.push(new Grocery(grocery.Id, grocery.Name));
});
return groceryList;
})
.catch(this.handleErrors);
}
handleErrors(error: Response) {
console.log(JSON.stringify(error.json()));
return Observable.throw(error);
}
}
One thing that's been bothering me is the usage of "Result" in the second .map function. Why not simply use:
data.forEach((grocery) => {
I am unsure whether "Result" is an object property of the resulting observable from .map(res => res.json()) or something else entirely. Can you help clarify where does "Result" originate from and its significance?
Any references or documentation regarding the origin and meaning of "Result" would be greatly appreciated.