[VIDEO] View not updating after the change in ngFor Array?

Ionic Framework ionic-v3
3

First, notification is received and the function saveNotificationToLocalStorage is called

// app.component.ts

OneSignal.handleNotificationReceived().subscribe((data) => {
        data.payload.rawPayload = JSON.parse(data.payload.rawPayload);
        this.user.saveNotificationToLocalStorage(data);
      });

// Function saveNotificationToLocalStorage … inside “providers/user-data.ts”

saveNotificationToLocalStorage(notification){
    var tmpNotification = notification.payload;
    var _isAppInFocus = notification.isAppInFocus;

    var tmpArr = JSON.parse(window.localStorage.getItem("arrayOfNotifs"));
    tmpArr.unshift(tmpNotification);
    window.localStorage.setItem("arrayOfNotifs", JSON.stringify(tmpArr));

    // Important part
    if(_isAppInFocus){
        this.events.publish('notifications:update', tmpArr);
    }
}

And then when event is fired “dashboard.ts”

listenToEvents(){
    this.events.subscribe('notifications:update', (notifications) => {
      this._notifications = notifications[0];
    });
  }

Dashboard.html

<ion-content no-margin no-padding>
  <ion-list no-margin no-padding [virtualScroll]="_notifications" approxItemHeight="40px">
    <ion-item-sliding #item *virtualItem="let notification" no-margin no-padding>
      <ion-item no-margin no-padding>
        {{ notification.title }}
      </ion-item>
      <ion-item-options side="right" no-margin no-padding>
        <button ion-button>
          <ion-icon ios="ios-archive" md="md-archive"></ion-icon>
          Save
        </button>
        <button ion-button color="danger">
          <ion-icon ios="ios-trash" md="md-trash"></ion-icon>
          Delete
        </button>
      </ion-item-options>
    </ion-item-sliding>
  </ion-list>
</ion-content>