malevic/state.mjs

Malevič.js - minimalistic reactive UI library

/* malevic@0.20.2 - Aug 10, 2024 */
import { getContext } from 'malevic/dom';

let currentUseStateFn = null;
function useState(initialState) {
    if (!currentUseStateFn) {
        throw new Error('`useState()` should be called inside a component');
    }
    return currentUseStateFn(initialState);
}
function withState(type) {
    const Stateful = (props, ...children) => {
        const context = getContext();
        const useState = (initial) => {
            if (!context) {
                return { state: initial, setState: null };
            }
            const { store, refresh } = context;
            store.state = store.state || initial;
            const setState = (newState) => {
                if (lock) {
                    throw new Error('Setting state during unboxing causes infinite loop');
                }
                store.state = Object.assign(Object.assign({}, store.state), newState);
                refresh();
            };
            return {
                state: store.state,
                setState,
            };
        };
        let lock = true;
        const prevUseStateFn = currentUseStateFn;
        currentUseStateFn = useState;
        let result;
        try {
            result = type(props, ...children);
        }
        finally {
            currentUseStateFn = prevUseStateFn;
            lock = false;
        }
        return result;
    };
    return Stateful;
}

export { useState, withState };