How to make some reusable QML object, which can inject another QML object?

Question

How to make some reusable QML object, which can inject another object?

I've ever tried to use Component & Loader , but seems not what I want. (It still encapsulate the whole QML type and lacks of elasticity, hard to reuse)

Usage example:

Card.qml

import QtQuick 2.0
import QtQuick.Layouts 1.3

Rectangle {
    default property var innerObject
    property string titleText: "[Hello Untitled Title]"
    id: root
    color: "#fff"
    ColumnLayout {
        anchors.fill: parent
        Rectangle {
            id: header
            height: 10
            width: parent.width
            color: "#666"
            RowLayout {
                Text { text: titleText; color: "#fff" }
            }
        }

        // How to inject innerObject in here ?

    }
}

main.qml

import QtQuick 2.0
import QtQuick.Layouts 1.3

Card {
    titleText: "Image Information"
    ColumnLayout { /* .......*/ }   // innerObject
}

Card {
    titleText: "Image Viewer"
    Rectangle { /* .......*/ }      // innerObject
}

Answer 1

The answer I linked works like this:

Main.qml

Card {
    titleText: "Image Viewer"
    innerObject: Rectangle {
        Component.onCompleted: {
            console.log(parent.objectName)
        }
    }
}

Card.qml

Rectangle {
    property string titleText: "[Hello Untitled Title]"

    default property alias innerObject : innercolumn.children


    id: root
    color: "#fff"
    ColumnLayout {
        id: innercolumn
        objectName: "column"
        anchors.fill: parent
        Rectangle {
            id: header
            height: 10
            width: parent.width
            color: "#666"
            RowLayout {
                Text { text: titleText; color: "#fff" }
            }
        }
    }
}