Static library does not work on iOS

cuongkjm

This is my project structure:
_TestQtSubDir.pro
___TestQtQuick.pro
___TestQtQuickStatic.pro

TEMPLATE = subdirs

SUBDIRS += \
    TestQtQuick \
    TestQtQuickStatic

TestQtQuick.depends = TestQtQuickStatic

"TestQtQuickStatic.pro" is a static library

QT += quick

TEMPLATE = lib
CONFIG += staticlib

CONFIG += c++17

# You can make your code fail to compile if it uses deprecated APIs.
# In order to do so, uncomment the following line.
#DEFINES += QT_DISABLE_DEPRECATED_BEFORE=0x060000    # disables all the APIs deprecated before Qt 6.0.0

SOURCES += \
    TestQtQuickStatic.cpp

HEADERS += \
    TestQtQuickStatic.h

RESOURCES += qml.qrc

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

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

# Default rules for deployment.
unix {
    target.path = $$[QT_INSTALL_PLUGINS]/generic
}
!isEmpty(target.path): INSTALLS += target

TestQtQuickStatic.h

#ifndef TESTQTQUICKSTATIC_H
#define TESTQTQUICKSTATIC_H

#include <QQmlApplicationEngine>

class TestQtQuickStatic
{
public:

    static TestQtQuickStatic* instance();
    void load_main_qml();

private:
    TestQtQuickStatic();

private:
    static TestQtQuickStatic* m_instance;
    QQmlApplicationEngine m_engine;
};

#endif // TESTQTQUICKSTATIC_H

TestQtQuickStatic.cpp

#include "TestQtQuickStatic.h"

TestQtQuickStatic* TestQtQuickStatic::m_instance = nullptr;

TestQtQuickStatic::TestQtQuickStatic()
{
}

TestQtQuickStatic *TestQtQuickStatic::instance()
{
    if (!m_instance)
        m_instance = new TestQtQuickStatic();
    return m_instance;
}

void TestQtQuickStatic::load_main_qml()
{
    const QUrl url(QStringLiteral("qrc:/main.qml"));
    m_engine.load(url);
}

main.qml

import QtQuick 2.15
import QtQuick.Window 2.15

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

    Text {
        id: name
        text: qsTr("Hello World")
        anchors.centerIn: parent
    }
}

TestQtQuick.pro is executable:

QT += quick

# You can make your code fail to compile if it uses deprecated APIs.
# In order to do so, uncomment the following line.
#DEFINES += QT_DISABLE_DEPRECATED_BEFORE=0x060000    # disables all the APIs deprecated before Qt 6.0.0

SOURCES += \
        main.cpp

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

INCLUDEPATH += $$PWD/../TestQtQuickStatic

LIBS += -L$$OUT_PWD/../TestQtQuickStatic -lTestQtQuickStatic

main.cpp

#include <QGuiApplication>
#include "TestQtQuickStatic.h"

int main(int argc, char *argv[])
{
#if QT_VERSION < QT_VERSION_CHECK(6, 0, 0)
    QCoreApplication::setAttribute(Qt::AA_EnableHighDpiScaling);
#endif

    Q_INIT_RESOURCE(qml);

    QGuiApplication app(argc, argv);
    TestQtQuickStatic::instance()->load_main_qml();
    return app.exec();
}

The application works ok on Windows and MacOS. But iOS show the following error:

QQmlApplicationEngine failed to load component
qrc:/main.qml:2:1: module "QtQuick.Window" is not installed
qrc:/main.qml:1:1: module "QtQuick" is not installed
qrc:/main.qml:2:1: module "QtQuick.Window" is not installed
qrc:/main.qml:1:1: module "QtQuick" is not installed

I am using Qt 5.15.2, MacOS Catalina, Xcode 12.4
What did i miss?

KH-219Design

It has been several years since I have targeted the iOS platform, but you might be able to find some hints by looking through a template project maintained by me and my co-workers.

Github Actions are supplying this project with Continuous Integration builds. You can check the actions and see that indeed our project successfully builds for iOS (although this does not prove that it launches on iOS, but I am confident that it does).

https://github.com/219-design/qt-qml-project-template-with-ci

(caveat: the project uses Xcode 11)

Perhaps more interesting is to simply look at the changes we made to our project in order to support iOS:

https://github.com/219-design/qt-qml-project-template-with-ci/pull/34

https://github.com/219-design/qt-qml-project-template-with-ci/pull/35

... actually... as I look back over those changes, I see that what you are likely missing is this special addition:

https://github.com/219-design/qt-qml-project-template-with-ci/blob/master/src/app/imports.qml

cuongkjm

@KH-219Design thank you so much, you save my day.
I add a "Imports.qml" to executable project with these import:

import QtQuick 2.15
import QtQuick.Window 2.15

QtObject {}