auto-focus.directive.ts

import {AfterViewInit, Directive, ElementRef, OnInit, Optional, Renderer} from '@angular/core';
import {ModalDirective} from 'ng2-bootstrap';

@Directive({
  selector: '[appAutoFocus]'
})
export class AutoFocusDirective implements OnInit, AfterViewInit {

  constructor(private el: ElementRef, private renderer: Renderer, @Optional() private modal: ModalDirective) {
  }

  ngOnInit() {
  }

  ngAfterViewInit() {
    if (!this.modal) {
      this.renderer.invokeElementMethod(this.el.nativeElement, 'focus', []);
    } else {
      this.modal.onShown.subscribe(
        () => {
          this.renderer.invokeElementMethod(this.el.nativeElement, 'focus', []);
        }
      );
    }
  }
}