Guard

import { Injectable } from '@angular/core'
import { CanDeactivate, Router } from '@angular/router'
import { Observable } from 'rxjs/Observable'
import 'rxjs/add/operator/delay'

@Injectable()
export class DelayDeactivate implements CanDeactivate<Observable<boolean>> {
  constructor(private router: Router) {}

  canDeactivate() {
    return Observable.of(true).delay(1000)
  }
}