Introduction

qmlprojectexporter is a tool that allows the automatic generation of C++ code for all the resources and .qml files included in your project. The resources can be Qml files, Images, Font files, Translation files, and C++ interfaces. You need to give a .qmlproject file as the main parameter to qmlprojectexporter. This file defines the project's structure and might depend on other .qmlproject module files.

qmlproject files

The syntax of a .qmlproject file uses the same syntax as Qml documents. The purpose of .qmlproject files is to describe the structure of a project.. Like QML documents, .qmlproject files consist of an import section followed by a hierarchy of nodes or objects, starting from the root Node (Project in this case), with each Node having a predefined set of properties. The import section consists mainly of "import QmlProject 1.3" which indicates that this is a .qmlproject file and specifies the version of the API that you are going to use.

Migration guide

You can migrate an existing project that depends on deprecated CMake APIs to use .qmlproject. Refer to the Migration guide to QmlProject for more information.

Exporting a project with platform sources

You can export a QmlProject together with platform sources using the qmlprojectexporter command-line utility. This simplifies the process of integrating Qt for MCUs into a 3rd party IDE or custom build system. See Exporting a Qt for MCUs project with platform sources for a detailed description of how to use this feature.

Nodes

Each Node configures a specific part of a project (Qml files, Images, Modules, among others). You might have the ability to define some nodes many times in the Project's root node, such as ImageFiles. Others you can only define once, for example, MCU.Module.

Properties

You can consider Properties in .qmlproject files as configuration parameters. Each node has a predefined set of possible configurations.

You have the possibility to assign configurations to all nodes that support them in the project file when you place them in MCU.Config node, and the value defined in MCU.Config will take effect if the respective properties are not found in their default Node (such as ImageFiles). Those configuration properties have the "MCU." prefix. For more information, see MCU.Config.

Nodes

Project

Each qmlproject file has the Project node as its root node. This root node includes all other nodes that give more information about the project.

The qmlproject file structure has a limit of two levels: Project and its children. qmprojectexporter will ignore nodes placed in a third level.

Usage

Project {
    projectRootPath: "..."
    ...
    MCU.Config {...}
    ...
    ImageFiles {...}
    ...
}

following is the list of available properties in the Project node:

QmlFiles

You can use this node to list QML files for a project. with the possibility to use both relative or absolute paths to the QML files.

Usage

QmlFiles {
    files: ["src/other.qml"]
}

following is the list of available properties in the QmlFiles Node:

ImageFiles

The ImageFiles node adds the given image assets to the project.

Additionally, the properties specified in a given node affect how the qulrcc-tool encodes these assets.

You can have more than one ImageFiles in the same project, you will need it when setting different properties per group of images.

If you do not define a given property in an ImageFiles node, qmlprojectexporter will use the default value provided in the MCU.Config node. If not defined there, then it will rely on global default values.

Usage

Project {
    ...
    ImageFiles {
        files: [...]
        MCU.resourceOptimizeForRotation: true
    }
    ...
}

following is the list of available properties in the ImageFiles node:

FontFiles

You can use this node to list font files required in a project. Refer to font formats for supported font file formats.

Usage

Project {
    ...
    FontFiles {
        files: [...]
    }
    ...
}

following is the list of available properties in the FontFiles node:

TranslationFiles

You can use this node to add translation files to a project (.ts).

qmlprojectexporter calls the corresponding tool to convert these translation files into .qm files, which is a binary format used by Qt for managing the translations.

In the QML sources, you can either use qsTr() or qsTrId() to mark the translatable strings. At runtime, the translation system looks for the matching string in the translation file for the current system locale.

Usage

Project {
    ...
    TranslationFiles {
        files: [...]
    }
    ...
}

The following properties are supported in the TranslationFiles node:

InterfaceFiles

This node provides the C++ interface-specific configuration. It is possible to define C++ interfaces and make them visible to Qml, without requiring to import them in a QML file. The qmlprojectexporter generates the QML code based on the header files for these C++ interfaces, so that another QML file in the same project could reference them.

Usage

Project {
    ...
    InterfaceFiles {
        files: [...]
    }
    ...
}

following is the list of available properties in the InterfaceFiles node:

MCU.Config

You can use this node to define default values for the QmlProject file. Properties defined within the context of this node do not need the "MCU." prefix, which you would need to use if the same property was part of a specific node such as ImageFiles, FontFiles, and so on.

Usage

//node1
MCU.Config {
  // Project-wide default value for resourceOptimizeForRotation.
  resourceOptimizeForRotation: true
}

ImageFiles {
  // Here resourceOptimizeForRotation was explicitly defined for a specific ImageFiles node.
  MCU.resourceOptimizeForRotation: false // requires the "MCU."prefix
}

//node2
ImageFiles {
  // MCU.resourceOptimizeForRotation was not defined but the value \c true will be
  // picked from MCU.Config.
}

following is the list of available properties in MCU.Config:

MCU.Module

This node's role is to declare a qmlproject file as a module. Modules can contain assets, interfaces, QML components and translations. A qmlproject-based project can make use of a qmlproject-based module by use of QmlProject's ModuleFiles node.

Usage

// mymodule.qmlproject
import QmlProject 1.3
Project {
  MCU.Module {
    uri: "custom.module"
  }
  QmlFiles {
    files: ["CustomBox.qml"]
  }
}

// CustomBox.qml
// ... some qml code

// main.qmlproject
import QmlProject 1.3
Project {
  QmlFiles {
    files: ["main.qml"]
  }
  ModuleFiles {
    files: ["mymodule.qmlproject"]
  }

// main.qml
import QtQuick 2.15
import custom.module
Rectangle {
  CustomBox {}
}

Qul Modules

Qt Quick Ultralite comes with the following predefined modules that projects can use with ModuleFiles.MCU.qulModules:

• Controls
• ControlsTemplates
• Profiling
• Shapes
• StudioComponents
• Timeline

following is the list of available properties in the MCU.Module node:

ModuleFiles

You can use this node to import QML modules into a project.

Usage

Project {
    ...
    ModuleFiles {
        MCU.qulModules: [...]
        ...
    }
    ...
}

following is the list of available properties in the ModuleFiles node:

Command line reference

qmlprojectexporter

Use the qmlprojectexporter to export the QML sources, image assets and fonts into compilable c++ code. It parses a .qmlproject file listing the assets with exporting options. In addition, qmlprojectexporter also exports plain-text lists of the imported and exported files, for convenient automatic use by a 3rd party build system, such as CMake.

Usage of qmlprojectexporter in a CMake project

Using qmlprojectexporter with a CMake build system is straightforward and the custom CMake macro qul_add_target already takes care of calling qmlprojectexporter with the right parameters, and it requires defining the QML_PROJECT argument followed by a qmlproject file as shown next.

// Adding the \l GENERATE_ENTRYPOINT option will generate an application entrypoint automatically,
// but it requires setting the \l Project.mainFile property
qul_add_target(my_project QML_PROJECT my_project.qmlproject GENERATE_ENTRYPOINT)

// Note for a working Qul application with CMake it is still required to call \l app_target_setup_os macro
// after adding the qmlproject target.
app_target_setup_os(myproject)

When using qmlprojectexporter, the following CMake macros are not needed as calling qmlprojectexporter implies performing the same function.

• qul_target_qml_sources
• qul_target_generate_interfaces
• qul_target_embed_translations
• qul_add_qml_module

All CMake flags replaced by a QmlProject alternative are marked as deprecated in CMake Manual.

Using standalone qmlprojectexporter

When using a build system other than CMake it is still possible to use qmlprojectexporter directly. You can use the generated assets files in a build system of choice.

qmlprojectexporter --outdir output_directory myproject.qmlproject

Here is the extended list of qmlprojectexporter's command-line arguments:

qmlprojectexporter's generated files

The files generated in the output directory vary depending on which command line arguments you are using. To better understand what role qmlprojectexporter plays in the project build process see Qt Quick Ultralite tools Following is the list of possible generated files depending on the next example:

Considering the following startup project files:

No Export

qmlprojectexporter --no-export-cpp --no-export-modules --no-export-configuration --outdir output my_project.qmlproject

Running this command will create the output directory but no files within it, as the command disables all exports.

Export Configurations

qmlprojectexporter --no-export-cpp --no-export-modules --outdir output my_project.qmlproject

Removing the --no-export-configuration argument will result in the following files :

The earlier command gives the possibility to fetch information on what resources or configurations the project expects without the overhead of generating the files.

Export CPP files

qmlprojectexporter --no-export-modules --outdir output my_project.qmlproject

While removing --no-export-configuration will list the configurations, removing --no-export-cpp will generate all the actual CPP files for the project. Qt Quick Ultralite tools gives an introduction to which tools are responsible for which files.

Export Modules

qmlprojectexporter --outdir output my_project.qmlproject

Running qmlprojectexporter on the earlier example without the --no-export-modules will not have a big effect on the output folder as the example does not use any module file. however two files will show up on the output directory used by 3rd party tools when the project is fully exported with its modules, those files are:

To see the main effect of --no-export-modules consider the new project files

Running the earlier qmlprojectexporter command with the new files will result in the following

qmlprojectexporter will generate configuration txt files if you omit --no-export-modules and use --no-export-cpp.

Export Modules

The generated files in the next step are not required when you have an existing entrypoint. Considering the following command.

//[1]
qmlprojectexporter --generate-entrypoint --target-type executable --outdir output my_project.qmlproject
//[2]
qmlprojectexporter --generate-entrypoint --target-type static_library --outdir output my_project.qmlproject

qmlprojectexporter introduces new files to the list of generated files depending on the --target-type flag. When using executable:

When using static_library: