ECMQmlModule

This file contains helper functions to make it easier to create QML modules. It takes care of a number of things that often need to be repeated. It also takes care of special handling of QML modules between shared and static builds. When building a static version of a QML module, the relevant QML source files are bundled into the static library. When using a shared build, the QML plugin and relevant QML files are copied to the target’s RUNTIME_OUTPUT_DIRECTORY to make it easier to run things directly from the build directory.

Since 6.0.0, when using Qt 6, most functionality of this module has been implemented by upstream Qt. Most of the functions here will now forward to the similar Qt functions.

Example usage:

ecm_add_qml_module(ExampleModule URI "org.example.Example")

target_sources(ExampleModule PRIVATE ExamplePlugin.cpp)
target_link_libraries(ExampleModule PRIVATE Qt::Quick)

ecm_target_qml_sources(ExampleModule SOURCES ExampleItem.qml) # This will have 1.0 as the default version
ecm_target_qml_sources(ExampleModule SOURCES AnotherExampleItem.qml VERSION 1.5)

ecm_finalize_qml_module(ExampleModule DESTINATION ${KDE_INSTALL_QMLDIR})

ecm_add_qml_module(<target name>
    URI <module uri>
    [VERSION <module version>]
    [NO_PLUGIN] # Deprecated since 6.0.0 when using Qt 6
    [CLASSNAME <class name>] # Deprecated since 6.0.0 when using Qt 6, use CLASS_NAME instead
    [QT_NO_PLUGIN] # Since 6.0.0, when using Qt 6
    [GENERATE_PLUGIN_SOURCE] # Since 6.0.0, when using Qt 6
)

This will declare a new CMake target called <target name>. The URI argument is required and should be a proper QML module URI. The URI is used, among others, to generate a subdirectory where the module will be installed to.

If the VERSION argument is specified, it is used to initialize the default version that is used by ecm_target_qml_sources when adding QML files. If it is not specified, a default of 1.0 is used. Additionally, if a version greater than or equal to 2.0 is specified, the major version is appended to the Qt5 installation path of the module. In case you don’t specify and version, but specify a version for the individual sources, the latest will be set as the resulting version for this plugin. This will be used in the ECMFindQmlModule module.

If the option NO_PLUGIN is set, a target is declared that is not expected to contain any C++ QML plugin.

If the optional CLASSNAME argument is supplied, it will be used as class name in the generated QMLDIR file. If it is not specified, the target name will be used instead.

You can add C++ and QML source files to the target using target_sources and ecm_target_qml_sources, respectively.

Since 5.91.0

Since 6.0.0, when used with Qt 6, this will forward to qt_add_qml_module. Any extra arguments will be forwarded as well. The NO_PLUGIN argument is deprecated and implies GENERATE_PLUGIN_SOURCE, since modules in Qt 6 always require a plugin or backing target. If you want to use Qt’s behaviour for NO_PLUGIN, use QT_NO_PLUGIN instead. Additionally, to maintain backward compatibility, by default we pass NO_GENERATE_PLUGIN_SOURCE to qt_add_qml_module. To have Qt generate the plugin sources, pass GENERATE_PLUGIN_SOURCE.

ecm_add_qml_module_dependencies(<target> DEPENDS <module string> [<module string> ...])

Add the list of dependencies specified by the DEPENDS argument to be listed as dependencies in the generated QMLDIR file of <target>.

Since 5.91.0

Since 6.0.0, this is deprecated and ignored when using Qt 6, instead use the DEPENDENCIES and IMPORTS arguments to ecm_add_qml_module.

ecm_target_qml_sources(<target> SOURCES <source.qml> [<source.qml> ...] [VERSION <version>] [PATH <path>] [PRIVATE])

Add the list of QML files specified by the SOURCES argument as source files to the QML module target <target>.

If the optional VERSION argument is specified, all QML files will be added with the specified version. If it is not specified, they will use the version of the QML module target.

If the optional PRIVATE argument is specified, the QML files will be included in the target but not in the generated qmldir file. Any version argument will be ignored.

The optional PATH argument declares a subdirectory of the module where the files should be copied to. By default, files will be copied to the module root.

This function will fail if <target> is not a QML module target or any of the specified files do not exist.

Since 5.91.0

Since 6.0.0, when used with Qt 6, this will forward to qt_target_qml_sources(). The SOURCES argument will be translated to QML_SOURCES. VERSION and PRIVATE will set Qt’s QT_QML_SOURCE_VERSIONS and QT_QML_INTERNAL_TYPE properties on SOURCES before calling qt_target_qml_sources(). Since Qt includes the path relative to the current source dir, for each source file a resource alias will be generated with the path stripped. If the PATH argument is set, it will be prefixed to the alias. Any additional arguments will be passed to qt_target_qml_sources().

ecm_finalize_qml_module(<target>
    [DESTINATION <QML install destination>] # Optional since 6.0
    [VERSION <Project Version>] # Added for 6.0 when using Qt 6
)

Finalize the specified QML module target. This must be called after all other setup (like adding sources) on the target has been done. It will perform a number of tasks:

  • It will generate a qmldir file from the QML files added to the target. If the module has a C++ plugin, this will also be included in the qmldir file.

  • If BUILD_SHARED_LIBS is off, a QRC file is generated from the QML files added to the target. This QRC file will be included when compiling the C++ QML module. The built static library will be installed in a subdirection of DESTINATION based on the QML module’s uri. If this value is not set, KDE_INSTALL_QMLDIR will be used. Note that if NO_PLUGIN is set, a C++ QML plugin will be generated to include the QRC files.

  • If BUILD_SHARED_LIBS in on, all generated files, QML sources and the C++ plugin will be installed in a subdirectory of DESTINATION based upon the QML module’s uri. In addition, these files will also be copied to the target’s RUNTIME_OUTPUT_DIRECTORY in a similar subdirectory.

This function will fail if <target> is not a QML module target.

Since 5.91.0

Since 6.0.0, when using Qt 6, this will instead install the files generated by qt_add_qml_module. The optional VERSION argument was added that will default to PROJECT_VERSION and which will write a file that is used by ECMFindQmlModule to detect the version of the QML module.

Since 6.1.0

Enabling the option VERBOSE_QML_COMPILER will activate verbose output for qmlcachegen.