reactive-react-redux/dist/useSelector.js

React Redux binding with React Hooks and Proxy

"use strict";

Object.defineProperty(exports, "__esModule", {
  value: true
});
exports.useSelector = void 0;

var _react = require("react");

var _Provider = require("./Provider");

var _utils = require("./utils");

function _slicedToArray(arr, i) { return _arrayWithHoles(arr) || _iterableToArrayLimit(arr, i) || _nonIterableRest(); }

function _nonIterableRest() { throw new TypeError("Invalid attempt to destructure non-iterable instance"); }

function _iterableToArrayLimit(arr, i) { if (!(Symbol.iterator in Object(arr) || Object.prototype.toString.call(arr) === "[object Arguments]")) { return; } var _arr = []; var _n = true; var _d = false; var _e = undefined; try { for (var _i = arr[Symbol.iterator](), _s; !(_n = (_s = _i.next()).done); _n = true) { _arr.push(_s.value); if (i && _arr.length === i) break; } } catch (err) { _d = true; _e = err; } finally { try { if (!_n && _i["return"] != null) _i["return"](); } finally { if (_d) throw _e; } } return _arr; }

function _arrayWithHoles(arr) { if (Array.isArray(arr)) return arr; }

var isFunction = function isFunction(f) {
  return typeof f === 'function';
};

var defaultEqualityFn = function defaultEqualityFn(a, b) {
  return a === b;
};

var useSelector = function useSelector(selector, eqlFn, opts) {
  var _ref = opts || !isFunction(eqlFn) && eqlFn || {},
      _ref$equalityFn = _ref.equalityFn,
      equalityFn = _ref$equalityFn === void 0 ? isFunction(eqlFn) ? eqlFn : defaultEqualityFn : _ref$equalityFn,
      _ref$customContext = _ref.customContext,
      customContext = _ref$customContext === void 0 ? _Provider.defaultContext : _ref$customContext;

  var _useReducer = (0, _react.useReducer)(function (c) {
    return c + 1;
  }, 0),
      _useReducer2 = _slicedToArray(_useReducer, 2),
      forceUpdate = _useReducer2[1];

  var _useContext = (0, _react.useContext)(customContext),
      state = _useContext.state,
      subscribe = _useContext.subscribe;

  var selected = selector(state);
  var ref = (0, _react.useRef)(null);
  (0, _utils.useIsomorphicLayoutEffect)(function () {
    ref.current = {
      equalityFn: equalityFn,
      selector: selector,
      state: state,
      selected: selected
    };
  });
  (0, _react.useEffect)(function () {
    var callback = function callback(nextState) {
      try {
        if (ref.current.state === nextState || ref.current.equalityFn(ref.current.selected, ref.current.selector(nextState))) {
          // not changed
          return;
        }
      } catch (e) {// ignored (stale props or some other reason)
      }

      forceUpdate();
    };

    var unsubscribe = subscribe(callback);
    return unsubscribe;
  }, [subscribe]);
  return selected;
};

exports.useSelector = useSelector;