Bevy Scripting

LADfiles

BMS provides a custom Language Agnostic Declaration format (LAD), which can be used to integrate with other tooling.

If you use #[script_bindings] macros, these files will magically contain your code comments, bindings as well as everything else required to drive other powerful integrations.

The declaration file is generated from the type registry and serves as a light abstraction layer simplifying the traversal of all available types and globals as well as functions.

You can customize how / where and if these files are stored using the main BMS plugin group:

    app.add_plugins(BMSPlugin.set::<ScriptingFilesGenerationPlugin>(
        ScriptingFilesGenerationPlugin::new(
            true, // enabled, you can use a compilation feature to disable this here
            PathBuf::from("assets").join("definitions"),
            Some(PathBuf::from("bindings.lad.json")), // do also save the ladfile itself
            "Core BMS framework bindings",
            true,
            true,
        ),
    ));

This plugin is only available when one of the sub features (like lua_language_server_files) mentioned in this chapter is enabled.

You might not want to run this pipeline in your final binary, but rather bundle some of the generated files into some sort of development pack for modding. You can use compiler flags like #[cfg(not(debug_assertions))] to disable ladfile generation at runtime, or simply disable the lower level features within BMS to avoid compiling related dependencies too.

Lua Language Server

Luals or LLS, is an open source language server which integrates with many IDE's.

It is powered by lua specific annotation or definition files which BMS can generate directly from its own LADfiles.

To enable this simply enable the lua_language_server_files feature, and a bindings.lua definition file will be generated in the LADfile output directory in the Startup schedule.

Script writers can then use this generated file by pointing their .luarc.json file to these definitions:

{
    "$schema": "https://raw.githubusercontent.com/LuaLS/vscode-lua/master/setting/schema.json",
    "workspace.library": [
        "assets/definitions"
    ],
    "runtime.version": "Lua 5.4",
    "hint.enable": false,
}