Passing data between QML. A QML <-> B QML

[IRRIS]

Hi everyone,

I am a beginner in QML. I am alone and ask for help.

Load B QML dynamically from A QML.

This is what you asked before.
Couldn't solve it.

[A QML]

Loader {
        id: testButton
        source: "qrc:/B.qml"
        x: 100; y: 100
        width: 200
        height: 100
    }

[B QML]

Rectangle {
    id: bQml

    property alias upData1: "aaaa"
    property alias upData2: "bbbb"
    property alias upData3: "cccc"

"A QML" loaded "B QML".
How can I change the values of upData1, upData2, upData3 of "B QML" in "A QML"?

Please help.

[oria66]

Hi. You can access the inner properties using the item of Loader. Example: testButton.item.upData1 or testButton.item.upData2 or testButton.item.upData3.

[IRRIS]

@oria66

Loader {
        id: testButton
        source: "qrc:/B.qml"
        x: 100; y: 100
        width: 200
        height: 100
        testButton.item.upData1 : "aaa"
    }

If you do the above, you will get an error.

"Invalid property name "testButton". (M16)

Please give an exact example.
I need it so much.

[freedbrt]

Loader {
        id: testButton
        source: "qrc:/B.qml"
        x: 100; y: 100
        width: 200
        height: 100
        onLoaded: {
           item.upData1 = ...;
           item.upData2 = ...;
       }
    } 

Other way, you can fill initial properties using setSource function - https://doc.qt.io/qt-5/qml-qtquick-loader.html#setSource-method

Loader {
        id: testButton
        x: 100; y: 100
        width: 200
        height: 100

        Component.onCompleted: {
                setSource("qrc:/B.qml",
                                     { "upData1": "abc",  
                                       "upData2": "bca", 
                                       "upData3": Qt.binding(() => ... // if you need binding
                                     });
        }  
    } 
}

[fcarney]

Start working through this book. It should give you solid understanding of QML.

[IRRIS]

@freedbrt
Thank you for your valuable information.
check the binding!

[IRRIS]

@fcarney
thank you I will study hard.