sample.ts

constructor(http: HttpClient, @Inject('BASE_URL') baseUrl: string) {
  this._http = http;
  this._baseUrl = baseUrl;

  // get data source structure from Web API endpoint 'LoadData'
  http.get<any>(baseUrl + 'textcontrol/loaddata').subscribe(result => {

    // call JavaScript function from injected 'textcontrol.js'
    loadData(result);

  }, error => console.error(error));
}