one/dist/cjs/background/useBackgroundComputation.cjs

One is a React framework for web, iOS, and Android apps.

var __defProp = Object.defineProperty;
var __getOwnPropDesc = Object.getOwnPropertyDescriptor;
var __getOwnPropNames = Object.getOwnPropertyNames;
var __hasOwnProp = Object.prototype.hasOwnProperty;
var __export = (target, all) => {
	for (var name in all) __defProp(target, name, {
		get: all[name],
		enumerable: true
	});
};
var __copyProps = (to, from, except, desc) => {
	if (from && typeof from === "object" || typeof from === "function") {
		for (let key of __getOwnPropNames(from)) if (!__hasOwnProp.call(to, key) && key !== except) __defProp(to, key, {
			get: () => from[key],
			enumerable: !(desc = __getOwnPropDesc(from, key)) || desc.enumerable
		});
	}
	return to;
};
var __toCommonJS = (mod) => __copyProps(__defProp({}, "__esModule", { value: true }), mod);
var useBackgroundComputation_exports = {};
__export(useBackgroundComputation_exports, { useBackgroundComputation: () => useBackgroundComputation });
module.exports = __toCommonJS(useBackgroundComputation_exports);
var import_react = require("react");
var import_createLatestComputation = require("./createLatestComputation.cjs");
function useBackgroundComputation(definition, input) {
	const [state, setState] = (0, import_react.useState)({
		phase: "idle",
		revision: 0
	});
	const owner = (0, import_react.useRef)(null);
	const submitted = (0, import_react.useRef)(null);
	const active = input !== null;
	(0, import_react.useLayoutEffect)(() => {
		if (!active) return;
		const computation = (0, import_createLatestComputation.createLatestComputation)(definition, (changed) => {
			setState(changed.phase === "ready" ? {
				phase: "ready",
				revision: changed.result.revision
			} : changed);
		});
		owner.current = computation;
		return () => {
			owner.current = null;
			submitted.current = null;
			computation.dispose();
		};
	}, [active, definition]);
	(0, import_react.useLayoutEffect)(() => {
		if (input === null) return;
		submitted.current = {
			input,
			factory: definition
		};
		owner.current?.update(input);
	}, [
		active,
		definition,
		input
	]);
	const getCurrent = (0, import_react.useCallback)(() => owner.current?.getCurrent() ?? null, []);
	const matches = active && submitted.current?.input === input && submitted.current.factory === definition;
	if (matches && state.phase === "failed") throw state.error;
	const current = owner.current?.getCurrent();
	const result = matches && state.phase === "ready" && current && state.revision === current.revision ? current : null;
	return {
		result,
		getCurrent
	};
}