QML Plugin QQmlComponent: Component is not ready

[Redman]

Hello,

I'm just starting with QML so bare with me.

I have a client qml application and a qml plugin.

Client Cmake

project(Client)
qt_add_executable(${PROJECT_NAME}
        src/main.cpp
)
qt_standard_project_setup(REQUIRES 6.5)

qt_add_qml_module(${PROJECT_NAME}
    URI ${PROJECT_NAME}
    QML_FILES
        src/qml/application.qml
)

set_target_properties(${PROJECT_NAME} PROPERTIES OUTPUT_NAME ${PROJECT_NAME})

# Link against libraries
target_link_libraries(${PROJECT_NAME} PRIVATE
    Qt${QT_MAJOR_VERSION}::RemoteObjects
    Qt${QT_MAJOR_VERSION}::Gui
    Qt${QT_MAJOR_VERSION}::Quick
    MyPlugin <-- is this actually needed?
)

Client main.cpp

#include <QtQuick>
int
main(int argc, char* argv[]) {
   // Init Gui Application
   QGuiApplication app(argc, argv);
   QQmlEngine engine;
   QQmlComponent component(&engine,
       QUrl("qrc:/qt/qml/Client/src/qml/application.qml"));
   QObject* appWindow = component.create();

application.qml (example application.qml from docs)

//import related modules
import QtQuick 2.15
import QtQuick.Controls

//window containing the application
ApplicationWindow {

    visible: true

    //title of the application
    title: qsTr("Hello World")
    width: 640
    height: 480

    //menu containing two menu items
    menuBar: MenuBar {
        Menu {
            title: qsTr("File")
            MenuItem {
                text: qsTr("&Open")
                onTriggered: console.log("Open action triggered");
            }
            MenuItem {
                text: qsTr("Exit")
                onTriggered: Qt.quit();
            }
        }
    }

    //Content Area

    //a button in the middle of the content area
    Button {
        text: qsTr("Hello World")
        anchors.horizontalCenter: parent.horizontalCenter
        anchors.verticalCenter: parent.verticalCenter
    }
}

This part works fine.

Now to my plugin
MyPlugin Cmake

Project(MyPlugin)

qt_add_qml_module(${PROJECT_NAME}
    URI MyPlugin
    VERSION 1.0
    SOURCES
        src/MyPlugin.h
    QML_FILES
        src/qml/MyPlugin.qml

)

target_sources(${PROJECT_NAME}
  PRIVATE
    src/qml/MyPlugin.qml
)
qt_standard_project_setup()

set_target_properties(${PROJECT_NAME} PROPERTIES
    LIBRARY_OUTPUT_DIRECTORY "${PROJECT_BINARY_DIR}/../../../../../plugins"
)

target_link_libraries(${PROJECT_NAME} PRIVATE
    Qt${QT_MAJOR_VERSION}::Core
    Qt${QT_MAJOR_VERSION}::Gui
    Qt${QT_MAJOR_VERSION}::Quick
)

MyPlugin.h

#ifndef MYPLUGIN_H
#define MYPLUGIN_H

#include <QQmlExtensionPlugin>

class MyPlugin : public QQmlExtensionPlugin {
   Q_OBJECT
   Q_PLUGIN_METADATA(IID QQmlExtensionInterface_iid)
 public:
   void
   registerTypes(const char* uri) {}
};

#endif MYPLUGIN_H

MyPlugin.qml (just some random code I copied)

import QtQuick 2.15
import QtQuick.Controls

Item {
    //a button in the middle of the content area
    Button {
        text: qsTr("Hello World")
        anchors.horizontalCenter: parent.horizontalCenter
        anchors.verticalCenter: parent.verticalCenter
    }
}

Now, when I add the import MyPlugin 1.0 to application.qml I get
QQmlComponent: Component is not ready. If I take it out, there is no error and the application serves as intended.

Ctrl+mouseleft jumps to the correct qml. Dont know if it's because qtcreator is smart or its looking that up in the QML_IMPORT_PATH which indicates at least some succes.

[Redman]

@Redman

https://www.youtube.com/watch?v=5YoEjIbzBA0 followed the steps in this video. Now it works. Missing was the qt_add_library(${PROJECT_NAME} STATIC), RESOURCE_PREFIX myplugin/imports and QQmlEngine engine; engine.addImportPath(":/myplugin/imports");