Generated Vehicle Config Pages

This page explains how the Vehicle Setup pages (Power, Safety, etc.) are generated from JSON definitions and how to extend them.

For the complete JSON schema reference see tools/generators/config_qml/README.md.

Architecture Overview

The generation pipeline is:

1. JSON page definitions in src/AutoPilotPlugins/APM/VehicleConfig/*.VehicleConfig.json
2. Python generator in tools/generators/config_qml/ (model.py loads the JSON, emit.py renders QML)
3. Generated QML in build/src/AutoPilotPlugins/APM/generated/
4. C++ component class (e.g. APMPowerComponent) loads the generated QML via setupSource()

At build time, CMake runs the generator for the ArduPilot plugin and places generated QML files in the build tree. Those files are compiled into the QGroundControl.AutoPilotPlugins.APM QML module.

Where Generation Is Wired

Generation is configured in the ArduPilot plugin's CMakeLists.txt:

• src/AutoPilotPlugins/APM/CMakeLists.txt — target GenerateConfigQmlAPM

PX4 setup pages are hand-written QML built from row definitions, so PX4 has no generation target.

Each runs:

python -m tools.generators.config_qml.generate_pages \
    --pages-dir <pages_dir> \
    --output-dir <build_gen_dir>

The generator entry point is tools/generators/config_qml/generate_pages.py; model.py loads and validates page definitions and emit.py renders the QML.

Base Class: VehicleComponent

VehicleComponent (in src/AutoPilotPlugins/VehicleComponent.h) provides the C++ side for generated pages. It reads the same JSON file at runtime to:

• Build the sidebar section list (including expanded repeat sections)
• Dynamically filter disabled repeat instances from the sidebar
• Connect signals so the sidebar updates when enable parameters change

Subclasses only need to implement vehicleConfigJson() to return the path to the JSON file and setupSource() to return the generated QML URL.

Adding a New Generated Setup Page

1. Create a new JSON file in the appropriate VehicleConfig/ directory:

   src/AutoPilotPlugins/APM/VehicleConfig/MyFeature.VehicleConfig.json

   See tools/generators/config_qml/README.md for the full JSON schema.

2. Create a minimal C++ component class inheriting VehicleComponent:

   • Implement vehicleConfigJson() to return the JSON path
   • Implement setupSource() to return the generated QML URL

3. Register the component in the firmware plugin's AutoPilotPlugin subclass.

4. Build. CMake picks up the new JSON file and generates its QML automatically:

   cmake --build build --config Debug --target GenerateConfigQmlAPM

Important Notes

• The constants, params, and bindings sections should appear before sections in the JSON file for readability, since sections reference them.
• Constants should use native JSON numbers, not strings (e.g. 0 not "0").
• Inside repeat sections, use parameter postfixes in param fields and _fullParamName() in showWhen expressions.
• The enableParam/disabledParamValue pair is required together — you cannot specify one without the other.