onChange hook

This hook might be used for many use cases. One of them to update the view after state was changed if you are not using:

• actions

• async pipes

for example:

Selected location: {{ location }}

location: any;

constructor(private store: Store<any>, private cd: ChangeDetectorRef) { }

ngOnInit() {
    this.filters = new FormGroup({
        condition: new FormGroup({
            new: new FormControl(false),
            used: new FormControl(false),
            notSpecified: new FormControl(false)
        }),
        location: new FormControl()
    });

    this.store.select(['form', 'location']).subscribe(state => this.location = state);

    this.ngFormStateManager = this.store.select(['form'])
        .form.bind(this.filters)
        .shouldUpdateState((params: ShoulUpdateStateParams) => true)
        .onChange(state => this.cd.markForCheck());
}

This event will not be triggered if you are updating form state from the code manually