I've created a couple of my own objects, container and item
Items are movable and periodically I check for some condition, let's say fot objects intersection.
If required event occurs, the object emits a signal:

Qt Code: 
  1. class Container : public QQuickItem {
  2. public:
  3. 	void checkIntersection() {
  4. 		foreach (QObject *child, childItems()) {
  5. 			if (MyObject *obj = dynamic_cast<MyObject*>(child)) {
  6. 				... 
  7. 				if(intersected(obj,other_obj)) emit intersect(other_obj);
  8. 			}
  9. 		}
  10. 	}
  11. 	bool intersected(MyObject * obj,MyObject * other) {
  12. 		...
  13. 		return true;
  14. 	}
  15. signals:
  16. 	intersect(MyObject * other);	
  17. }
  18.  
  19. class MyObject : public QQuickItem {
  20. 	...
  21. }
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and QML structure for better understanding:
Qt Code: 
  1. Container {
  2. 	MyObject {
  3. 		id: object1
  4. 		...
  5. 		onIntersect: {
  6. 			if(other.id === "object2") { // error, id is undefined
  7. 				doSomething();
  8. 			}
  9. 		}
  10. 	}
  11. 	MyObject {
  12. 		id: object2
  13. 		...
  14. 	}	
  15. }
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As you can see, when I trying to get object property (id) I get error. I can read some properties, width or height for example, but id is inaccesible.
What I do wrong?