Precompiling QML. Can't find modules error

Kory

Hello,

So as some context to the problem, I would like to hide the QML source code whilst meeting LGPL requirements with dynamic linking and it seems like the best strategy for this is to precompile the QML

From what I understand, to precompile QML, I need to add "ENABLE_TYPE_COMPILER" to main project qt_add_qml_module CmakeLists.txt file

https://doc.qt.io/qt-6/qtqml-qml-type-compiler.html

The problem I'm having though is that the moment I add "ENABLE_TYPE_COMPILER", I receive an error that it can't find the modules. Before I used modules, I had include file path directories for the QML components and had a similar error for this. Like it not being able to find stuff

Error: Path/Main.qml:8:1: Warnings occurred while importing module "NameOfModule": [import]
import NameOfModule 1.0
^^^^^^
---
Error: Failed to import NameOfModule. Are your import paths set up properly? [import]
---

Does anybody have experience with precompiling QML for the LGPL version of Qt (so I'm NOT able to use qmlsc, "which is a part of the commercial-only add-on Qt Quick Compiler Extensions."
https://doc.qt.io/qt-6/qtqml-qml-script-compiler.html
But AM able to use qmltc and qmlcachegen
https://doc.qt.io/qt-6/qtqml-qml-type-compiler.html
https://doc.qt.io/qt-6/qtqml-tool-qmlcachegen.html)?

Perhaps you would know why it can find the module without ENABLE_TYPE_COMPILER but not with it. I mean if there's any projects that have done this even a GitHub link would be helpful to see if there's anything they might have had to do to make precompiling QML work.

In the main project Cmake file, I have all the things that I'd expect would be sufficient since it works with this without ENABLE_TYPE_COMPILER included in qt_add_qml_module

# Making our main program module accessible
add_subdirectory(import/qml_module/NameOfModule)

set_property(TARGET appAppName_lib
             PROPERTY QML_IMPORT_PATH "${CMAKE_CURRENT_SOURCE_DIR}/import/qml_module")

Then in the QML file itself, I have what we'd also expect to see

import NameOfModule 1.0

Kory

I forgot to mention that we also have

target_link_libraries(
  appAppName_lib
  PUBLIC nameOfModuleplugin # our external module
     )

Kory

Okay for debugging purposes, I realized I could just use ENABLE_TYPE_COMPILER on the single module only and try to debug it

For one of my pure QML only text modules, it complains

This is my QML file BodyTextBase

import QtQuick
import QtQuick.Layouts

Text {
    readonly property font bodyTextFont: Qt.font({
    "family": "Helvetica",
    "weight": Font.Normal,
    "italic": false,
    "pointSize": 16
    })

    readonly property color bodyTextFontColor: "black"

    font: bodyTextFont
    color: bodyTextFontColor
    wrapMode: Text.Wrap
    Layout.fillWidth: true
}

This was the Cmake file for this child module

# File: import/qml_module/TextModule/CMakeLists.txt

# Define the static library for the QML module
qt_add_library(text_module STATIC)

set_target_properties(text_module PROPERTIES AUTOMOC ON)
target_link_libraries(text_module PRIVATE
    Qt6::Quick
)

list(APPEND MODULE_QML_FILES
    BodyTextBase.qml
    ClickableLinkBase.qml
    Header1Base.qml
    Header2Base.qml
    Header3Base.qml
    Header4Base.qml
    Header5Base.qml
    Header6Base.qml
    ProgramTitleBase.qml
)

# Define the QML module
qt_add_qml_module(text_module
    URI TextModule
    VERSION 1.0
    RESOURCE_PREFIX /
    ENABLE_TYPE_COMPILER
    QML_FILES
        ${MODULE_QML_FILES}
)

It can't find some stuff from the auto-generated code

Issues I see

ChatGPT summary of the the warnings

### Errors in the `TextModule` build process:

1. **Missing Header Files:**
   Several errors are caused by missing files. The following files cannot be found:
   - `private/qquickevents_p_p.h`
   - `private/qquicklayout_p.h`
   - `private/qquickcolorgroup_p.h`

2. **Undeclared Identifiers:**
   In the following files, there are instances of undeclared identifiers:
   - `QQuickText`: This identifier is used but not declared in `bodytextbase.h`.
   - `QQuickLayoutAttached`: The error suggests this might be a typo and should be `QQuickWindowAttached`.

3. **Expected Class Name:**
   In `bodytextbase.h`, there's an issue where the compiler expects a class name, but something else is provided, resulting in an error.

4. **Build Stopped:**
   The build was stopped by `ninja` due to the errors encountered during compilation. 

---

These issues suggest that certain required Qt internal files are missing, and there are some coding or configuration issues related to undeclared or mistyped identifiers. You may need to check the configuration of your Qt environment, verify that all necessary Qt modules are included, and review the mentioned source files for the correct usage of identifiers and header files.