Angular2 http get request with Observables and dynamic url params. How to? - http

Question

Having this angular2 service taken from official docs with Observable, trying to modify to can pass on fly to the base heroesUrl dynamic parameters like app/heroes/{{country}} and use it like
getHeroes(country) {}
import { Injectable } from '#angular/core';
import { Http, Response } from '#angular/http';
import { Hero } from './hero';
import { Observable } from 'rxjs/Observable';
#Injectable()
export class HeroService {
constructor (private http: Http) {}
private heroesUrl = 'app/heroes'; // URL to web API
getHeroes (): Observable<Hero[]> {
return this.http.get(this.heroesUrl)
.map(this.extractData)
.catch(this.handleError);
}
private extractData(res: Response) {
let body = res.json();
return body.data || { };
}
private handleError (error: any) {
// In a real world app, we might use a remote logging infrastructure
// We'd also dig deeper into the error to get a better message
let errMsg = (error.message) ? error.message :
error.status ? `${error.status} - ${error.statusText}` : 'Server error';
console.error(errMsg); // log to console instead
return Observable.throw(errMsg);
}
}
How would I do that?

Answer 1

I think you just need to do following things if I understood your point,
getHeroes(country) {}
export class HeroService {
constructor (private http: Http) {}
private heroesUrl = 'app/heroes'; // URL to web API
getHeroes (country): Observable<Hero[]> { //<-----added parameter
return this.http.get(this.heroesUrl + '/' + country) //<-----changed
.map(this.extractData)
.catch(this.handleError);
}
...
...
}