Nodejs api call from angular2 service - node.js

Question

I have node api that returns data to browser using this api :
app.get('/api/patients',function(req,res){
Patient.getPatients(function(err,patients){
if(err){
throw err;
}
console.log(patients.length);
res.json(patients);
});
});
I am trying to call this api from the service class.
import { Injectable } from '#angular/core';
import { Patient } from '../patient.interface';
#Injectable()
export class PatientDataService {
patients : Patient[] =[];
constructor() { }
getAllPatients(): Patient[]
{
// What to do here ??
}
}
How do i return data from node api to service ?

Answer 1

Use this
#Injectable()
export class PatientDataService {
patients : Patient[] =[];
constructor(private http:Http) { }
getAllPatients()
{
return this.http.get('base_url/api/people').map((res)=>res.json());
}
}
and in your component inject this service and call
this.patientService.getAllPatients().subscribe((data)=>{
//data is your patient list
})

Answer 2

You can first import the Angular2 Http library into your service:
import { Http } from '#angular/http';
I also import rx/js for use of Observables and mapping.
import { Observable } from 'rxjs/Observable';
import 'rxjs/add/operator/catch';
import 'rxjs/add/operator/map';
You can then inject the library into your service:
constructor(private _http: Http) { }
Make your http call to your node.js server like this:
getAllPatients(): Patient[]
{
// What to do here ??
return this._http.get('/api/patients')
.map(this.extractData)
.catch(this.handleError);
}
For more information, documentation, and clarification please read the Angular 2 Http Docs