Singleton woes

[GrahamLa]

Hi
I am at loss with singletons - I have been following an example from the web that runs as expected. But when I developed my own it does not work.
I would be grateful if someone could explain why I get
module "MySingleton" is not installed

.pro

QT += qml quick
CONFIG += c++11

# The following define makes your compiler emit warnings if you use
# any Qt feature that has been marked deprecated (the exact warnings
# depend on your compiler). Refer to the documentation for the
# deprecated API to know how to port your code away from it.
DEFINES += QT_DEPRECATED_WARNINGS

# You can also make your code fail to compile if it uses deprecated APIs.
# In order to do so, uncomment the following line.
# You can also select to disable deprecated APIs only up to a certain version of Qt.
#DEFINES += QT_DISABLE_DEPRECATED_BEFORE=0x060000    # disables all the APIs deprecated before Qt 6.0.0

SOURCES += \
        main.cpp

RESOURCES += qml.qrc

# Additional import path used to resolve QML modules in Qt Creator's code model
QML_IMPORT_PATH = MySingleton

# Additional import path used to resolve QML modules just for Qt Quick Designer
QML_DESIGNER_IMPORT_PATH = MySingleton

# Default rules for deployment.
qnx: target.path = /tmp/$${TARGET}/bin
else: unix:!android: target.path = /opt/$${TARGET}/bin
!isEmpty(target.path): INSTALLS += target

main.cpp

#include <QGuiApplication>
#include <QQmlApplicationEngine>

int main(int argc, char *argv[])
{
    QCoreApplication::setAttribute(Qt::AA_EnableHighDpiScaling);

    QGuiApplication app(argc, argv);

    QQmlApplicationEngine engine;
    engine.addImportPath("qrc:/MySingleton");
    engine.load(QUrl(QStringLiteral("qrc:/main.qml")));
    if (engine.rootObjects().isEmpty())
        return -1;

    return app.exec();
}

main.qml

import MySingleton 1.0
import QtQuick 2.9
import QtQuick.Window 2.2


Window {
    visible: true
    width: 640
    height: 480
    title: qsTr("Hello World")
}

MySingleton.qml

pragma Singleton
import QtQuick 2.0
import QtQuick.Window 2.2

QtObject {
    property color labelColor: "white"
}

qmldir

module MySingleton
singleton MySingleton 1.0 MySingleton.qml

[raven-worx]

@GrahamLa said in Singleton woes:

engine.addImportPath("qrc:/MySingleton");

should rather be engine.addImportPath(":/")

Alternatively (considering your current qrc structure) in your main.qml you can also do: import "MySingleton"

[GrahamLa]

@GrahamLa
Ahhhh - thanks

[GrahamLa]

@GrahamLa
However, in Creator my import statement is still reporting module not found, but the application runs - any ideas?

[GrahamLa]

@GrahamLa
In addition if I move MySingleton outside of the qrc it is no longer found??

[raven-worx]

@GrahamLa
my advice: simply ignore it.
QtCreator wont inspect into qrc. But you've set the QML_IMPORT_PATH qmake variable which is responsible for this. This variable should contain the (import-)path - a filesystem path to the folder containing the MySingleton directory.

[raven-worx]

@GrahamLa said in Singleton woes:

In addition if I move MySingleton outside of the qrc it is no longer found??

if you move it you have to let the qml engine know where to find it of course.
I thought this is clear by answering your initial question already where the module couldn't be found?

[GrahamLa]

@raven-worx
Yep - I'm getting the hang of it now
Thanks