How do you POST a FormData object in Angular 2?

Template:

<label class="btn btn-primary">
  <input type="file" style="display: none;" multiple="true" (change)="fileChange($event)" accept=".xml">
  <span>Click Me!</span>
</label>

UPD: Angular 5 – HttpClient + Typescript

onFileUpload(event: EventTarget) {

  const eventObj: MSInputMethodContext = <MSInputMethodContext>event;
  const target: HTMLInputElement = <HTMLInputElement>eventObj.target;
  const files: FileList = target.files;

  const formData: FormData = new FormData();

  for (let i = 0; i < files.length; i++) {
    formData.append('file', files[i]);
  }

  // POST
  this.httpClient.post<AnalyzedData>(uploadUrl, formData).subscribe(...);
}

old Http lib – before Angular 4.3:

fileChange(event) {
    let files = event.target.files;
        if (files.length > 0) {
        let formData: FormData = new FormData();
        for (let file of files) {
             formData.append('files', file, file.name);
        }
        let headers = new Headers();
        headers.set('Accept', 'application/json');
        let options = new RequestOptions({ headers: headers });
        this.http.post(uploadURL, formData, options)
            .map(res => res.json())
            .catch(error => Observable.throw(error))
            .subscribe(
            data => {
                // Consume Files
                // ..
                console.log('uploaded and processed files');
            },
            error => console.log(error),
            () => {
                this.sleep(1000).then(() =>
                    // .. Post Upload Delayed Action
                )
            });
    }
}