Important: Please read the Qt Code of Conduct -

Can I using Qt.createComponent() in WorkerScript function?

  • I'm new in Qt quick app. (QML)

    I wanna create dynamic image table(like in Samegame example) but it using thread to make real-time create by using workerScript.

    How to using WorkerScript by Qt function can be passed between the new thread and the parent thread? or can import Qt func in javascript?

    import QtQuick 1.0

    Rectangle {
    width: 800; height: 600

    WorkerScript {
        id: myWorker
        source: "script.js"
    Item {
         id: container
         anchors.fill: parent
    Component.onCompleted: myWorker.sendMessage({ 'container':container })


    WorkerScript.onMessage = function(message) {
    // error occur in this below line with TypeError: Result of expression 'Qt.createComponent' [undefined] is not a function.
    var component = Qt.createComponent("Imgbox.qml");
    if (component.status == Component.Ready) {
    var img = component.createObject(message.container);

    import QtQuick 1.0

    Image {
    id: img
    source: "./img.jpg"; clip: true


  • No, the JavaScript code in a WorkerScript is run in a separate thread, and QML objects should only be created in the main thread, in the same thread as the QML engine.

  • Are you sure?
    I need to do that, and I have watched some code with QML code in Javascript. But you need to configure .qmlproject file. Really I don't know how to do it. But I'm figuring out.
    So, Is there someone who got this?


  • There is no QQmlEngine in the WorkerScript thread, only a JavaScript engine. Attempting to create a component in a thread which has no QQmlEngine cannot succeed. You can create QObjects in a WorkerScript thread, but not QML items (well, you technically could create a QQuickItem, but it wouldn't be usable).

    You can interact with certain QML items from within functions in a WorkerScript (e.g., ListModel items are a good example) but some magic happens behind the scenes to allow that.

Log in to reply