Ongoing problem, trying to create manager in singleton...

[SPlatten]

The issues:

QQmlApplicationEngine failed to load component
qrc:/stage.qml:135:5: Type DataModel unavailable qrc:/stage.qml: 135
<Unknown File>:138:5: Element is not creatable.

stage.qml:

import QtQuick 2.0
import QtQuick.Controls 2.15
import QtQuick.Controls.Styles 1.4
import QtQuick.Layouts 1.3
import QtQuick.Extras 1.4
import QtQuick.Window 2.12

Window {
    property string dptTag: "DPT"
    property string hdgTag: "HDG"
    property bool dptTestDataEnabled : false
    property bool hdgTestDataEnabled : false

    id: root
    visible: true
    width: 640
    height: 480    
    title: qsTr("Playground / Staging Arena")

    Button {
        id: btnDptData
        text: "DPT Click Me..."
        anchors {
            left: parent.left
            top: parent.top
        }
        onClicked: {
            var value = dpt.getValue()
            if ( typeof value === "undefined" ) {
                value =  0.0
            } else {
                value = Number(value)
            }
            if ( dpt.setValue(value + 0.01) === true ) {
                btnClearDevFailure.clicked()
            }
        }
    }
    Button {
        id: btnDptTestData
        text: (dptTestDataEnabled == true) ? "Stop Test Data" : "Start Test Data"        
        anchors {
            left: btnDptData.right
            top: btnDptData.top
            leftMargin: 4
        }
        onClicked: {
            dptTestDataEnabled = (dptTestDataEnabled == true) ? false : true
            var api = dpt.api
            api.setTestData(dptTestDataEnabled)
            btnClearDevFailure.clicked()
        }
    }
    Button {
        id: btnHdgData
        text: "HDG Click Me..."
        anchors {
            left: btnDptData.left
            top: btnDptData.bottom
            topMargin: 4
        }
        onClicked: {
            var value = hdg.getValue()
            if ( typeof value === "undefined" ) {
                value =  0.0
            } else {
                value = Number(value)
            }
            if ( hdg.setValue(value + 0.01) === true ) {
                btnClearDevFailure.clicked()
            }
        }
    }
    Button {
        id: btnHdgTestData
        text: (hdgTestDataEnabled == true) ? "Stop Test Data" : "Start Test Data"        
        anchors {
            left: btnHdgData.right
            top: btnHdgData.top
            leftMargin: 4
        }
        onClicked: {
            hdgTestDataEnabled = (hdgTestDataEnabled == true) ? false : true
            var api = hdg.api
            api.setTestData(hdgTestDataEnabled)
            btnClearDevFailure.clicked()
        }
    }
    Button {
        id: btnDeviceFailure
        text: "Set Device Failure"
        enabled: !btnClearDevFailure.enabled
        anchors {
            left: btnDptData.left
            top: btnHdgData.bottom
            topMargin: 4
        }
        onClicked: {
            if ( dptTestDataEnabled == true ) {
                btnDptTestData.clicked()
            }
            if ( hdgTestDataEnabled == true ) {
                btnHdgTestData.clicked()
            }
            var api = dpt.api
            api.setInterfaceStatus(false)
            if ( dptTestDataEnabled == true ) {
                btnDptTestData.clicked()
            }
            api = hdg.api
            api.setInterfaceStatus(false)
            if ( hdgTestDataEnabled == true ) {
                btnHdgTestData.clicked()
            }
            btnDeviceFailure.enabled = false
        }
    }
    Button {
        id: btnClearDevFailure
        text: "Clr Device Failure"
        enabled: !btnDeviceFailure.enabled
        anchors {
            left: btnDeviceFailure.right
            top: btnDeviceFailure.top
            leftMargin: 4
        }
        onClicked: {
            var api = dpt.api
            api.setInterfaceStatus(true)
            api = hdg.api
            api.setInterfaceStatus(true)
            btnDeviceFailure.enabled = true
        }
    }
    DataModel {
        id: dpt
        anchors {
            right: parent.right
            top: parent.top
        }
        dataRef: "testData.testLink"
        device: "simulation"
        dataTag: dptTag
        logData: true
        ptszFont: 18
        strDefault: "N/A"
        strLabel: dptTag
        strUnits: "M"
        textWidth: 256
    }
    DataModel {
        id: hdg        
        anchors {
            right: parent.right
            top: parent.top
            topMargin: 80
        }
        dataTag: hdgTag
        device: "simulation"
        logData: true
        ptszFont: dpt.ptszFont
        strDefault: "N/A"
        strLabel: hdgTag
        strUnits: "\xB0"
        textWidth: dpt.textWidth
    }
}

DataModel.qml:

import QtQuick 2.0
import QtQuick.Controls 2.15
import QtQuick.Controls.Styles 1.4
import QtQuick.Layouts 1.3
import QtQuick.Extras 1.4
import QtQuick.Window 2.12
import Qt.DMngrSingleton 1.0

Item {
    id: root
    readonly property alias api           : datahlpr
    property int someValue                : DataMngr.someProperty
    property string argbData              : "#FF000000"
    property string argbLabel             : argbData
    property string argbStale             : "#FF777777"
    property string argbUnits             : argbData
    property bool logData                 : false
    readonly property string cstrInvalid  : "qrc:/images/invalid.svg"
    readonly property string cstrStale    : "qrc:/images/stale.svg"
    readonly property string cstrLinkFail : "qrc:/images/link-fail.svg"
    property bool blnValid                : false
    property var dataRef
    property var dataTag
    property string device
    property int intDecimalPlaces         : 4
    property int ptszFont                 : 14
    property int ptszData                 : 16
    property int ptszLabel                : 10
    property int ptszUnits                : 14
    property string strDefault            : ""
    property string strLabel              : ""
    property string strUnits              : ""
    property double textWidth             : 80
    property double timeout               : 5000
    property double timestamp

    Component.onCompleted: {
        console.log("HELLO FROM DataModel.qml")
        console.log(DataMngr.doSomething())

        if ( typeof root.dataTag === "string" ) {
            api.dataTag = root.dataTag
        }
        if ( typeof root.dataRef !== "undefined" ) {
            api.dataRef = root.dataRef
        }        
    }
/*
    onDeviceChanged: {
        api.device = root.device
    }
    function getValue(value, blnFormatOnly) {
        if ( typeof value === "undefined" && api.valid() ) {
            value = api.value
        }
        value = Number(value).toFixed(root.intDecimalPlaces)
        if ( typeof blnFormatOnly !== "undefined" ) {
            logMessage("getValue, typeof value: " + (typeof value) + ", value: " + value)
        }
        return value
    }
    function logMessage(strMsg) {
        if ( logData !== true || typeof strMsg !== "string" || strMsg.length === 0 ) {
            return
        }
        const dtNow = new Date()
        console.log(dtNow.toLocaleString() + " " + root.strLabel + " " + strMsg)
    }
    function setValue(newValue) {
        if ( api.value !== newValue ) {
            api.value = newValue
        }
    }
    Label {
        id: rUnits
        anchors.right: root.right
        anchors.top: root.top
        color: root.argbUnits
        font.pointSize: root.ptszUnits
        horizontalAlignment: Text.AlignRight
        verticalAlignment: Text.AlignTop
        text: {
            root.strUnits
                ? String(root.strUnits)
                : ""
        }
        visible: root.strUnits && root.strUnits.length > 0
    }
    Text {
        id: rText
        anchors {
            right: root.right
            rightMargin: rUnits.visible ? 24 : 0
            top: root.top
        }
        color: root.argbData
        font.pointSize: root.ptszData
        horizontalAlignment: Text.AlignRight
        text: root.strDefault
        verticalAlignment: Text.AlignTop
        width: root.textWidth
    }
    Label {
        id: rLabel
        anchors.right: rText.right
        anchors.top: rText.bottom
        color: root.argbLabel
        font.pointSize: root.ptszLabel
        horizontalAlignment: Text.AlignRight
        text: root.strLabel
        verticalAlignment: Text.AlignTop
    }
    Image {
        id: rImage
        visible: true
        anchors {
            right: rLabel.left
            verticalCenter: rLabel.verticalCenter
            verticalCenterOffset: 5
        }
        MouseArea {
            id: ma
            anchors.fill: parent
            hoverEnabled: true
            onContainsMouseChanged: {
                api.stale()
            }
        }
    }
    Timer {
        interval: 250
        running: true
        repeat: true
        onTriggered: {
            api.stale()
        }
    }
*/
    DataMngr {
        id: datahlpr
/*
        onDataChanged: {
            rText.text = root.getValue(dblData_, true)
        }
        onInterface: {
            logMessage(", Interface Status: " + blnState_)
        }
        onToolTip: {
            if ( api.valid() !== true ) {
                return
            }
            var blnVisible = (typeof strToolTip_ === "string" && strToolTip_.length > 0)
            if ( blnVisible === true ) {
                var strTagName = root.strLabel
                rText.color = root.argbStale
                rImage.ToolTip.text = strToolTip_
                if ( api.valid(root.strLabel) !== true ) {
                    rImage.source = cstrInvalid
                } else if (api.interfaceStatus() === true) {
                    rImage.source = cstrStale
                } else {
                    rImage.source = cstrLinkFail
                }
            } else {
                rText.color = root.argbData
            }
            rImage.ToolTip.visible = blnVisible && ma.containsMouse
            rImage.visible = blnVisible
        }
*/
    }
}

The singleton class:

class staledataSingleton_t;
typedef staledataSingleton_t DataMngrSingleton;   //For QML acccess
class staledataSingleton_t  : public QObject {
    Q_OBJECT
    Q_PROPERTY(int someProperty READ someProperty WRITE setSomeProperty NOTIFY somePropertyChanged)

public:
    explicit staledataSingleton_t(QObject* pParent = nullptr) : QObject(pParent) {}

    Q_INVOKABLE int doSomething() {
        setSomeProperty(5);
        return m_someProperty;
    }

    int someProperty() const { return m_someProperty; }
    void setSomeProperty(int val) {
        if (m_someProperty != val) {
            m_someProperty = val;
            emit somePropertyChanged(val);
        }
    }

signals:
    void somePropertyChanged(int newValue);

private:
    int m_someProperty = 0;
};

Registration:

    QCoreApplication::setAttribute(Qt::AA_EnableHighDpiScaling);
        QGuiApplication app(argc, argv);
    
        QScopedPointer<DataMngrSingleton> DMngrSingleton(new DataMngrSingleton);
        QQmlApplicationEngine engine;
    
        qmlRegisterSingletonInstance("Qt.DMngrSingleton", 1, 0, "DataMngr", DMngrSingleton.get());

This is very much a work in progress.

[J.Hilk]

@SPlatten said in Ongoing problem, trying to create manager in singleton...:

you have the singleton instance DataMngr and this one

 DataMngr {
         id: datahlpr

this is a naming conflict,

[SPlatten]

@J-Hilk , sorry, I was just going to delete this post, I've fixed the issue now. DataMngr was left in from the previous model, not required for this implementation.

[SPlatten]

@J-Hilk , is there a way to get the id of the instance of the QML document being created?

For example, I have DataModel.qml which internally has an id of root. Another QML document has two instances of this, each with an unique id for the instance.

Is there a way in the DataModel.qml to get the id that instantiates DataModel.qml ? or do I have to create another property and reference that?

[J.Hilk]

@SPlatten said in Ongoing problem, trying to create manager in singleton...:

or do I have to create another property and reference that

this one, ID is only available in the actual qml file

from the documentation:

An object can be referred to by its id from anywhere within the component scope in which it is declared. Therefore, an id value must always be unique within its component scope.

...

Once an object instance is created, the value of its id attribute cannot be changed. While it may look like an ordinary property, the id attribute is not an ordinary property attribute, and special semantics apply to it

[SPlatten]

@J-Hilk , so how can I determine in the singleton what the id of the object that is using it?

[J.Hilk]

@SPlatten via a custom property ? that you tell the manger