Is there a way to distinguish internally defined children from externally defined ones in QML? - qt

Question

I have defined a MyElement element (in the MyElement.qml file) as the following:
Rectangle {
Item {
}
Component.onCompleted: {
console.warn(children.length)
}
}
Let's call the Item element defined within MyElement the internal child. Now, I'm using the MyElement element in the following way:
MyElement {
Item {
}
}
Here another one Item element is used as a child of MyElement. Let's call this Item element the external child. To understand my question below one should clearly understand the difference between internal and external children.
The output for the presented code will be 2, i.e. both Item elements are calculated as children.
In the future I want to iterate in the block Component.onCompleted only over external children, not over internal (external children go after internal). But for this I have to know a children index from which I have to start (in the given example this index is 1). Is there a way to get this index or, in other words, the number of internal children? Thanks.

Answer 1

There is no internal mechanism in Qt to distinguish internal children from those which are defined outside of the own QML definition.
My workaround is as follow
//MyElement.qml
Rectangle {
id: root
readonly property Item last_item: lastone
Item {
id: someitem
}
Item {
id: lastone
}
Component.onCompleted: {
var external_started = false;
for(var i = 0 ; i < root.children.length ; ++i)
{
if(external_started)
console.log(root.children[i].toString(), 'is external');
else if(root.children[i]===last_item)
external_started = true;
}
}
}
and
MyElement {
Item {
objectName: 'I am external'
}
}
It's a dirty hack but it works.
I'm saving a reference to the last item in a readonly property called last_item and that will distinguish my last item in qml definition.
Other items which are added outside of the qml file, will be placed after this item in the children list.