constructor(
     elementRef: ElementRef,
     private rest: Rest,
     public api: ApiUrl) {
     this.id = elementRef.nativeElement.getAttribute('id');
     this.wi = elementRef.nativeElement.getAttribute('wi');
     this.rest.get(this.api.workitem(this.id, this.wi)).subscribe(dto => this.onItemLoaded(dto));
 }

 loadList(grade: number): Observable<any[]> {
     if (grade !== 0) {
         return this.rest.get(`${this.api.list()}?grade=${grade}`);
     } else {
         return this.rest.get(`${this.api.list()}`);
     }
 }

 protected onOpening(): Observable<any> {
     this.rest.get(`${this.api.item(0)}/tousers`).subscribe(dto => this.mentors = dto);
     return null;
 }

 updateSecretary(subjectId: string, secretaryId: string): Observable<void> {
     return this.rest.put(this.api.item(subjectId), {secretaryId});
 }

 updateDirector(subjectId: string, directorId: string): Observable<void> {
     return this.rest.put(this.api.item(subjectId), {directorId});
 }

 loadList(): Observable<any[]> {
     return this.rest.get(this.api.list());
 }

 downloadUrl(pre: string): string {
     return `${this.api.item(this.awardId)}/attachments?status=ALL&pre=${pre}`;
 }

 this.dialog.open(MentorSelectDialog).then(result => {
     this.rest.put(`${this.api.item(this.form.id)}`, {teacherId: result})
         .subscribe(() => this.form.paperApprover = result);
 });

 update(programId: number, options: any): Observable<void> {
     return this.rest.put(this.api.item(programId), options);
 }

 loadGrades(): Observable<any[]> {
     return this.rest.get(`${this.api.list()}/grades`);
 }