Getting ID of detail-page instance that is currently open

To handle how PushNotifications are shown to my users while the app is open, I need to identify, which page the user is currently on. I can do that by:

if ( (this.navCtrl.getActive().component === Page1) ){
    // user is currently on Page1
    // handle push notification
}

Unfortunately, this is not enough. Page 1 is a detail page, which shows details of an item. Let’s say there are 3 items: Banana (id: 1), Apple (id: 2) and Orange (id: 3).

I know need to know, whether the user is currently looking at Page1 for item1, item2 or item3. I want to do something like this:

if ( (this.navCtrl.getActive().component === Page1 && data.itemID === "page1-itemId") ){
    // data.itemID is the ID i get from the push notification
    // "page1-itemId" is what I desire to get somehow
}

How could I find out about page1-itemId?

Page1 knows what item it is showing, so why not delegate the question of how to handle the notification to the page instead of having a global monolithic dispatch function?

That sounds charming @rapropos. Up to now, I put the logic to handle the notification to my app.component.ts. There I’ve got someting like this:

FCMPlugin.onNotification( data => {

    if(data.wasTapped){
      // Handle notification that was received on device tray and tapped by the user.

    } else{
      // Handle notification that was received in foreground.
      // My logic depending on which item is shown...

      if ( (...) ){
        
      } 
    }
  });

Would you just move this code from app.component to Page1? I wasn’t sure if it would be called there anytime a new notification comes in, even if the user didn’t even open Page1.
Or would you somehow split the code between Page1 and app.components?

@rapropos: How would you delegate the question how to handle the notification to the page? I’m not sure how to do this, properly.

Just in case, anybody will struggle with the same thing: I decided to use Events for this purpose.

Whenever Page1 is opened, I publish an Event like this:

Page1.ts

constructor(...
     public events: Events
) {
     // read NavParams
     this.itemId= this.navParams.get('itemId');

     // publish event with current itemId
     this.events.publish("Page1:opened",this.itemId);
}

Then I listen to this event in my app.component.ts

// Listen to Opening of Confirm-Page
this.events.subscribe('Page1:opened', itemId=> {
   this.page1ItemId= itemId;
});

… and use this.page1ItemId in combination with this.nav.getActive().component === Page1 to handle the notification the way I want to.