ngOnInit(): void {
    this.oidc.init().subscribe(() => {}, error => console.warn(error));

    let defaultTitle = 'Pass Past';
    Observable.combineLatest(
      this.store.select(state => state.courses.course.selected),
      this.store.select(state => state.courses.paper.selected),
      this.store.select(state => state.courses.exam.selected)
    ).subscribe((selectedItems) => {
      let course = selectedItems[0];
      let paper = selectedItems[1];
      let exam = selectedItems[2];

      let title = `${course ? course.code : ''} ${paper ? paper.name : ''} ${exam ? exam.year : ''} ${exam ? exam.semester : ''}`;
      let oldTitle = this.title.getTitle();
      let equalTitles = title === oldTitle;

      if (title.trim() === '') {
        if (oldTitle !== defaultTitle) {
          this.title.setTitle(defaultTitle);
        }
      } else {
        if (title !== oldTitle) {
          this.title.setTitle(title);
        }
      }

    });
  }

  login(provider: string) {
    this.loadingBar.doWithLoader(this.oidc.loginExternal(provider))
      .do(() => {
        this.examHub.stop();
        this.examHub.start();
      })
      .subscribe(x => this.alert.sendSuccess('Successfully logged in'));

  }

      .flatMap(loggedIn => {
        if (loggedIn) {
          this.alertService.sendError('Unauthorized');
          this.router.navigate(['unauthorized']);
          return Observable.of(false);
        }

        return this.oidc.isInRole(role)
          .map(isInRole => {
            if (!isInRole) {
              this.alertService.sendError('Unauthorized');
              this.router.navigate(['unauthorized']);
              return false;
            }
            return true;
          });

      })

 logout() {
   this.oidc.logout();
 }

 registerGoogle() {
   this.oidc.registerExternal('google')
     .subscribe(x => {
       this.alert.sendSuccess('Successfully registered');
     });
 }

 registerFacebook() {
   this.oidc.registerExternal('facebook')
     .subscribe(x => {
       this.alert.sendSuccess('Successfully registered');
     });
 }