logos-app-builder provides the build infrastructure for UI/QML Logos modules and standalone application preview. It delegates C++ plugin compilation to logos-module-builder and layers on QML view bundling, standalone app wrapping, and UI integration tests.

What it provides

Function	Purpose
`mkLogosQmlModule`	Build ui_qml modules (QML-only or QML + C++ backend)
`mkLogosApp`	Add standalone app launching (`nix run`) to any UI module
`mkStandaloneApp`	Lower-level: wrap a plugin into a runnable app
`collectAllModuleDeps`	Resolve transitive module dependencies for bundling

What stays in logos-module-builder

Core/backend module building: mkLogosModule, buildCppPlugin, mkExternalLib, parseMetadata, mkLogosModuleTests, CMake macros, and core module templates.

Usage

QML-only module (no C++ backend)

# flake.nix
{
  inputs.logos-app-builder.url = "github:logos-co/logos-app-builder";

  outputs = inputs@{ logos-app-builder, ... }:
    logos-app-builder.lib.mkLogosQmlModule {
      src = ./.;
      configFile = ./metadata.json;
      flakeInputs = inputs;
    };
}

QML module with C++ backend

# flake.nix
{
  inputs = {
    logos-app-builder.url = "github:logos-co/logos-app-builder";
    some_module.url = "github:logos-co/logos-some-module";
  };

  outputs = inputs@{ logos-app-builder, ... }:
    logos-app-builder.lib.mkLogosQmlModule {
      src = ./.;
      configFile = ./metadata.json;
      flakeInputs = inputs;
    };
}

Legacy UI module (type: "ui") with standalone app

For legacy UI modules built with logos-module-builder.lib.mkLogosModule, use mkLogosApp to add apps output:

# flake.nix
{
  inputs = {
    logos-module-builder.url = "github:logos-co/logos-module-builder";
    logos-app-builder.url = "github:logos-co/logos-app-builder";
  };

  outputs = inputs@{ logos-module-builder, logos-app-builder, ... }:
    let
      module = logos-module-builder.lib.mkLogosModule {
        src = ./.;
        configFile = ./metadata.json;
        flakeInputs = inputs;
      };
      appOutputs = logos-app-builder.lib.mkLogosApp {
        packages = module.packages;
        configFile = ./metadata.json;
        flakeInputs = inputs;
      };
    in module // { inherit (appOutputs) apps; };
}

Templates

Scaffold a new UI module:

# QML-only module
nix flake init -t github:logos-co/logos-app-builder#ui-qml

# QML + C++ backend module
nix flake init -t github:logos-co/logos-app-builder#ui-qml-backend

metadata.json

UI modules use type: "ui_qml" and must specify a view field:

{
  "name": "my_ui_module",
  "version": "1.0.0",
  "type": "ui_qml",
  "view": "qml/Main.qml",
  "main": "my_ui_module_plugin",
  "dependencies": ["some_core_module"]
}

view (required): Path to the QML entry point
main (optional): C++ plugin name. Omit for QML-only modules.
dependencies: Core modules this UI depends on (resolved transitively)

Architecture

logos-app-builder
  ├── lib/
  │   ├── default.nix              # Entry point
  │   ├── mkLogosQmlModule.nix     # QML + optional C++ backend builder
  │   ├── mkLogosApp.nix           # Standalone app output for any UI module
  │   ├── mkStandaloneApp.nix      # Low-level standalone wrapper
  │   ├── collectAllModuleDeps.nix # Transitive dependency resolver
  │   └── parseMetadataInline.nix  # Lightweight metadata parser
  ├── templates/
  │   ├── ui-qml/                  # QML-only template
  │   └── ui-qml-backend/         # QML + C++ backend template
  └── tests/
      ├── test-qml-integration.nix
      ├── test-collectAllModuleDeps.nix
      └── fixtures/

Relationship with logos-module-builder

logos-app-builder takes logos-module-builder as a flake input and accesses its library functions via logos-module-builder.lib. When a QML module has a C++ backend (main is set in metadata.json), mkLogosQmlModule calls logos-module-builder.lib.buildCppPlugin for compilation, then bundles the result with the QML view.