"The @children placeholder cannot appear in a conditional element" why?

[Antonio225t]

if condition:
    VerticalLayout {
        @children // ERROR: The @children placeholder cannot appear in a conditional element
    }

Why this restriction?
Is there an alternative that I can use?

[ogoffart]

Because if you have something like so:

    YourComponent {
        inner-rect := Rectangle { 
           img := Image { ... }
        }
    }
    TouchArea {
       width: img.width;
       clicked=> { inner-rect.background = Colors.blue; }  
    }

Then it's not clear at the call site that inner-rect may be in a conditional or repeated, and then you can't take id from it. (the reference on the TouchArea will not work)

But we could allow @children there and then have an error in the call site when this happens. (I think we alrady made the same mistake with PopupWindow)

[Antonio225t]

Oh I understand. But it would have more sense if the TouchArea was inside the custom component right? I mean I know that this is just an example but I'm having trouble imagining a scenario where this would be usefull.

Btw can't the img.width have something default (like '0') when the component isn't shown?