use-form/lib/hooks/useSubscription.js

use-form

"use strict";
var __importDefault = (this && this.__importDefault) || function (mod) {
    return (mod && mod.__esModule) ? mod : { "default": mod };
};
exports.__esModule = true;
var nest_deep_1 = require("nest-deep");
var react_1 = require("react");
var isEqual_1 = __importDefault(require("../helpers/isEqual"));
function useSubscription(_a) {
    var getState = _a.getState, subscribe = _a.subscribe;
    var _b = react_1.useState(getState()), state = _b[0], setState = _b[1];
    react_1.useEffect(function () {
        var didUnsubscribe = false;
        var checkForUpdates = function () {
            if (didUnsubscribe) {
                return;
            }
            var nextState = getState();
            return setState(function (prevState) {
                if (isEqual_1["default"](nest_deep_1.flatten(state), nest_deep_1.flatten(nextState))) {
                    return prevState;
                }
                return nextState;
            });
        };
        checkForUpdates();
        var unsubscribe = subscribe(checkForUpdates);
        return function () {
            didUnsubscribe = true;
            unsubscribe();
        };
    }, [subscribe]);
    return state;
}
exports["default"] = useSubscription;