Struct LuaExtension 

pub struct LuaExtension { /* private fields */ }

A Lua script loaded as a kui Extension.

Load it with LuaExtension::from_file or LuaExtension::from_source, then hand it to a host: kui_native::app(..).extension_as(ns, ext) for a window, or a kui_core::Extensions list for a headless kui_core::Core. The host places the script by declaring a slot named ns/<slot>; the script’s view(env, slot) runs inside the host’s frame and its on_event(ev) hears the events its own nodes emit.

use kui_core::{Core, Extensions, NodeSpec, OriginId, Size, Value};
use kui_lua::LuaExtension;

let script = LuaExtension::from_source("panel.lua", r#"
    slots = { "panel" }
    function view(env, slot)
      return column { pad = 8, text(slot.params.title) }
    end
    function on_event(ev)
      if ev.kind == "pick" then return { kind = "picked" } end
    end
"#)?;

let mut exts = Extensions::new();
exts.push_as("fs", Box::new(script))?;

let mut core = Core::new();
let mut ui = core.frame_with(Size::new(400.0, 300.0), 1.0, &mut exts);
ui.configure_root(NodeSpec::row().fill());
ui.slot_with("fs/panel", &Value::map([("title", "files".into())]));
ui.finish();

// The script's nodes carry its origin, so the host can tell them apart.
let drawn = core.access_tree().nodes.iter().filter(|n| n.origin == OriginId(1)).count();
assert!(drawn > 0);

Implementations

impl LuaExtension

pub fn from_source(name: impl Into<String>, source: &str) -> Result<Self>

Loads a script from its source text; name is what errors call it.

The prelude is injected first, then the script runs once, and its slots and tokens globals are read. A script with no slots global fills "root".

use kui_core::{Core, Extension, Size, Slot};
use kui_lua::LuaExtension;

let mut ext = LuaExtension::from_source("hello.lua", r#"
    function view(env)
      return column { pad = 8, text("hello from Lua") }
    end
"#)?;
assert!(ext.slots().is_empty());

let mut core = Core::new();
let mut ui = core.frame(Size::new(320.0, 240.0), 1.0);
ext.view(&Slot::root(), &mut ui)?;
ui.finish();

pub fn lua(&self) -> &Lua

The script’s own interpreter, for a host that wants to seed a global the script reads: the escape hatch for facts that are neither env nor events.

pub fn from_file(path: impl AsRef<Path>) -> Result<Self>

Loads a script from a file; its file name becomes the script’s name.

Trait Implementations

impl Extension for LuaExtension

fn name(&self) -> &str

fn slots(&self) -> &[String]

The slot names this extension fills; empty means "root". The one entry crate::slot::ANY_SLOT ("*") means every name declared under its namespace, for an extension whose slots are not known when it loads — a Lua host whose init.lua registers views at runtime, one slot per view — and it then gets no unknown-slot warning, since there is no list to check against.

fn view(&mut self, slot: &Slot<'_>, ui: &mut Ui<'_>) -> Result<(), String>

fn on_event(&mut self, ev: &UiEvent) -> Vec<Value>

One of this extension’s events; the values returned are replies to the host, delivered in order.