svelte
Version:
Cybernetically enhanced web apps
81 lines (63 loc) • 1.87 kB
JavaScript
/** @import { TemplateNode, Dom, Effect } from '#client' */
/** @import { Batch } from '../../reactivity/batch.js'; */
import { EFFECT_TRANSPARENT } from '#client/constants';
import { block, branch, pause_effect } from '../../reactivity/effects.js';
import { current_batch } from '../../reactivity/batch.js';
import { hydrate_next, hydrate_node, hydrating } from '../hydration.js';
import { create_text, should_defer_append } from '../operations.js';
/**
* @template P
* @template {(props: P) => void} C
* @param {TemplateNode} node
* @param {() => C} get_component
* @param {(anchor: TemplateNode, component: C) => Dom | void} render_fn
* @returns {void}
*/
export function component(node, get_component, render_fn) {
if (hydrating) {
hydrate_next();
}
var anchor = node;
/** @type {C} */
var component;
/** @type {Effect | null} */
var effect;
/** @type {DocumentFragment | null} */
var offscreen_fragment = null;
/** @type {Effect | null} */
var pending_effect = null;
function commit() {
if (effect) {
pause_effect(effect);
effect = null;
}
if (offscreen_fragment) {
// remove the anchor
/** @type {Text} */ (offscreen_fragment.lastChild).remove();
anchor.before(offscreen_fragment);
offscreen_fragment = null;
}
effect = pending_effect;
pending_effect = null;
}
block(() => {
if (component === (component = get_component())) return;
var defer = should_defer_append();
if (component) {
var target = anchor;
if (defer) {
offscreen_fragment = document.createDocumentFragment();
offscreen_fragment.append((target = create_text()));
}
pending_effect = branch(() => render_fn(target, component));
}
if (defer) {
/** @type {Batch} */ (current_batch).add_callback(commit);
} else {
commit();
}
}, EFFECT_TRANSPARENT);
if (hydrating) {
anchor = hydrate_node;
}
}