tests.service.ts

import { Injectable } from '@angular/core';
import { Http, Headers, Response, RequestOptions, URLSearchParams } from '@angular/http'
import { Observable } from 'rxjs/Rx'
import { Test } from '../models/test'
import { AuthenticationService } from './authentication.service';

// Import RxJs required methods
import 'rxjs/add/operator/map';
import 'rxjs/add/operator/catch';

@Injectable()
export class TestsService {

  constructor(
    private http: Http,
    private authenticationService: AuthenticationService) { }

  // Fetch student's test information
  getStudentTestScores(studentId) : Observable<Test[]> {
    const headers = new Headers({ 'Authorization': 'Bearer ' + this.authenticationService.token });
    const options = new RequestOptions({
        headers: headers,
    });

    return this.http.get(`http://SERVER:3000/api/tests/student/${studentId}`, options)
        .map((res:Response) => res.json())
        .catch((error:any) => Observable.throw(error.json().error || 'Server error'));

  }

  // Fetch all tests
  getTestScores(queryObject) : Observable<Test[]> {
    let params: URLSearchParams = new URLSearchParams();
    for(var queries = 0; queries < queryObject.length; queries++){
      Object.keys(queryObject[queries]).forEach(key => {
        params.set(key, queryObject[queries][key]);
      });
    }
    const headers = new Headers({ 'Authorization': 'Bearer ' + this.authenticationService.token });
    const options = new RequestOptions({
      headers: headers,
      search: params,
    });

    return this.http.get(`http://SERVER:3000/api/tests`, options)
      .map((res:Response) => res.json())
      .catch((error:any) => Observable.throw(error.json().error || 'Server error'));

  }

}