launch.io/dist/esm/hooks/useLaunch.js

Launch.IO is an Ultra Hip, Simple, and Fast, Time Traveling React State Management Library

import { useCallback, useLayoutEffect, useRef, useState } from "react";
import ctx from "../utils/context";
import useContextListener from "../utils/useContextListener";
/**
 * A React hook that takes a `selector` function.  The selector function receives a context, containing `state` and `actions`, and it should return object containing Launch.IO state and/or actions.
 *
 * `const selection = useLaunch({ state, actions} => ({ ... }));`
 *
 * `state` is an object that will contain the full application state.
 * These can be accessed via the name of the service along with the associating state property.
 * For example, `state.[ServiceName].[ServiceStateProperty]`
 *
 * `actions` is an object that will contain the full application launch actions.
 * These can be accessed via the name of the service along with the associating action.
 * For example, `actions.[ServiceName].[LaunchAction]`
 *
 */
export const useLaunch = (selector) => {
    const selectedStateRef = useRef();
    const selectorRef = useRef(selector);
    const [selectedState, setSelectedState] = useState(() => selector(ctx.snapshot()));
    useLayoutEffect(() => {
        selectedStateRef.current = selectedState;
        selectorRef.current = selector;
    });
    const onContextChange = useCallback((context) => {
        const newState = selectorRef.current(context);
        if (newState !== selectedStateRef.current) {
            setSelectedState(newState);
        }
    }, []);
    useContextListener(onContextChange);
    return selectedState;
};