Angular use modal dialog in canDeactivate Guard service for unsubmitted changes (Form dirty)

Question

In my Angular 4 application I have some components with a form, like this:

export class MyComponent implements OnInit, FormComponent {

  form: FormGroup;

          


        

Answer 1

In addition to ShinDarth's good solution, it seems worth mentioning that you will have to cover a dismissal of the modal as well, because the action() method might not be fired (e.g. if you allow the esc button or click outside of the modal). In that case the observable never completes and your app might get stuck if you use it for routing.

I achieved that by subscribing to the bsModalService onHide property and merging this and the action subject together:

confirmModal(text?: string): Observable {
    const subject = new Subject();
    const modal = this.modalService.show(ConfirmLeaveModalComponent);
    modal.content.subject = subject;
    modal.content.text = text ? text : 'Are you sure?';
    const onHideObservable = this.modalService.onHide.map(() => false);
    return merge(
      subject.asObservable(),
      onHideObservable
    );
  }

In my case I map the mentioned onHide observable to false because a dismissal is considered an abort in my case (only a 'yes' click will yield a positive outcome for my confirmation modal).