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vacuum-wall/webui/static/hoover/component.js
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JavaScript

/**
* Hoover — component.js
*
* Component wrapper: definePage, lifecycle hooks, state caching.
*
* definePage wraps a page definition into a renderer function compatible
* with hoover's render engine. Handles reactive state creation, WS
* subscription registration on mount, and cleanup on unmount.
*
* Usage:
* export default definePage({
* init() { return { data: null, loading: true, error: null }; },
* subscribe: ['*'], // WS topics to subscribe to
* async load(state) { ... }, // called on mount
* render(state) { return [vnodes],
* });
*/
import { reactive } from './reactivity.js';
import { h } from './vdom.js';
import { _compExpandedCache } from './render.js';
/**
* Registry of mounted components: key → { state, subscriptions, loadAbort, entry }
*/
const _mounted = new Map();
/**
* External subscribe function from websocket.js.
* Set via setSubscribeFn() when the websocket module initializes.
*/
let _subscribeFn = null;
export function setSubscribeFn(fn) {
_subscribeFn = fn;
}
/**
* Define a page component.
*
* @param {object} def — Page definition
* @param {function} def.init — Return initial state object
* @param {string[]} [def.subscribe] — WS topics to subscribe to on mount
* @param {function} def.load — Async function to load data into state
* @param {function} def.render — Render function that returns vnodes
* @returns {object} — Component renderer compatible with h('#comp', ...)
*/
export function definePage(def) {
const state = reactive(def.init());
const renderer = () => {
return def.render(state);
};
renderer._pageDef = {
state,
subscribe: def.subscribe || [],
load: def.load || null,
onUnmount: def.onUnmount || null,
};
return renderer;
}
/**
* Mount a page component. Called by the render engine when a #comp vnode
* enters the tree for the first time.
*/
export function mountComponent(key, renderer) {
// Prevent duplicate mounts when normalization loses #comp tracking
if (_mounted.has(key)) return;
const pd = renderer._pageDef;
if (!pd) return;
const entry = {
state: pd.state,
subscriptions: [],
loadAbort: null,
};
_mounted.set(key, entry);
// Fire load
if (pd.load) {
const abortController = new AbortController();
entry.loadAbort = abortController;
pd.load(pd.state, abortController);
}
// Register WS subscriptions
if (_subscribeFn && pd.subscribe.length) {
for (const topic of pd.subscribe) {
const unsub = _subscribeFn(renderer, topic, pd.load, pd.state);
if (unsub) entry.subscriptions.push(unsub);
}
}
}
/**
* Unmount a page component. Called by the render engine when a #comp vnode
* is removed from the tree.
*/
export function unmountComponent(key, renderer) {
const entry = _mounted.get(key);
if (!entry) return;
const pd = renderer._pageDef;
// Cancel load
if (entry.loadAbort) {
entry.loadAbort.abort();
}
// Unsubscribe from WS
for (const unsub of entry.subscriptions) {
try { unsub(); } catch (_) {}
}
// Fire custom onUnmount
if (pd.onUnmount) {
try { pd.onUnmount(entry.state); } catch (_) {}
}
_compExpandedCache.delete(key);
_mounted.delete(key);
}
/**
* Get the state of a mounted component.
*/
export function getComponentState(key) {
const entry = _mounted.get(key);
return entry ? entry.state : null;
}
/**
* Create a component vnode that the render engine will wire up to lifecycle.
*/
export function hComp(renderer, key) {
return h('#comp', { component: renderer, key }, []);
}