@alshdavid/reactive/preact/index.module.js

Generic object mutation observation

import { useState, useMemo, useEffect } from 'preact/hooks';
import { create } from '../reactive/create.module.js';
import { observe } from '../reactive/observe.module.js';
import '../reactive/index.module.js';

const isConstructor = (f) => {
    try {
        Reflect.construct(String, [], f);
    }
    catch (e) {
        return false;
    }
    return true;
};
const useViewModel = (ctor, args = []) => {
    const [, forceUpdate] = useState(false);
    const vm = useMemo(() => {
        if (isConstructor(ctor)) {
            const $Ctor = create(ctor);
            return new $Ctor(...args);
        }
        else {
            return create(ctor());
        }
    }, [window]);
    useEffect(() => {
        if (vm.onInit) {
            vm.onInit();
        }
        const sub = observe(vm).subscribe(() => forceUpdate(s => !s));
        return () => {
            sub.unsubscribe();
            if (vm.onDestroy) {
                vm.onDestroy();
            }
        };
    }, [window]);
    return vm;
};

export default useViewModel;
export { useViewModel };