@shoutem/redux-composers/lib/mapReducers.js

Reducers you can use for composing reducer hierarchy like with combineReducers from redux

"use strict";

Object.defineProperty(exports, "__esModule", {
  value: true
});
exports.TARGET_ALL_REDUCERS = exports.TARGET_ALL_OPTION_KEY = void 0;
exports.applyToAll = applyToAll;
exports["default"] = mapReducers;
exports.isTargetAllAction = isTargetAllAction;
exports.isTargetAllKey = isTargetAllKey;
exports.mapReducer = mapReducer;
exports.mapReducerFactory = mapReducerFactory;

var _identity2 = _interopRequireDefault(require("lodash/identity"));

var _mapValues2 = _interopRequireDefault(require("lodash/mapValues"));

var _get2 = _interopRequireDefault(require("lodash/get"));

var _isEmpty2 = _interopRequireDefault(require("lodash/isEmpty"));

var _isString2 = _interopRequireDefault(require("lodash/isString"));

var _isFunction2 = _interopRequireDefault(require("lodash/isFunction"));

var _shallowequal = _interopRequireDefault(require("shallowequal"));

var _actionOptions = require("./actionOptions");

function _interopRequireDefault(obj) { return obj && obj.__esModule ? obj : { "default": obj }; }

function ownKeys(object, enumerableOnly) { var keys = Object.keys(object); if (Object.getOwnPropertySymbols) { var symbols = Object.getOwnPropertySymbols(object); if (enumerableOnly) { symbols = symbols.filter(function (sym) { return Object.getOwnPropertyDescriptor(object, sym).enumerable; }); } keys.push.apply(keys, symbols); } return keys; }

function _objectSpread(target) { for (var i = 1; i < arguments.length; i++) { var source = arguments[i] != null ? arguments[i] : {}; if (i % 2) { ownKeys(Object(source), true).forEach(function (key) { _defineProperty(target, key, source[key]); }); } else if (Object.getOwnPropertyDescriptors) { Object.defineProperties(target, Object.getOwnPropertyDescriptors(source)); } else { ownKeys(Object(source)).forEach(function (key) { Object.defineProperty(target, key, Object.getOwnPropertyDescriptor(source, key)); }); } } return target; }

function _defineProperty(obj, key, value) { if (key in obj) { Object.defineProperty(obj, key, { value: value, enumerable: true, configurable: true, writable: true }); } else { obj[key] = value; } return obj; }

// Action marked as TARGET_ALL_OPTION_KEY bypass key:reducer relationship at map reducers
// and dispatch action to all mapped reducers.
var TARGET_ALL_OPTION_KEY = 'targetAll'; // If key selector returns TARGET_ALL_REDUCERS value, all mapped reducers will be activated

exports.TARGET_ALL_OPTION_KEY = TARGET_ALL_OPTION_KEY;
var TARGET_ALL_REDUCERS = 'TARGET_ALL';
exports.TARGET_ALL_REDUCERS = TARGET_ALL_REDUCERS;

function validateKeySelector(keySelector) {
  if (!(0, _isFunction2["default"])(keySelector)) {
    if (!(0, _isString2["default"])(keySelector)) {
      throw new Error('KeySelector argument should be a function or a string');
    }

    if ((0, _isEmpty2["default"])(keySelector)) {
      throw new Error('KeySelector argument is empty string.');
    }
  }
}

function resolveKey(action, keySelector) {
  var resolvedKey = (0, _isFunction2["default"])(keySelector) ? keySelector(action) : (0, _get2["default"])(action, keySelector);
  return resolvedKey || TARGET_ALL_REDUCERS;
}
/**
 * Calculates new state for all keys applying reducer resolved based on key,
 * if state is not modified returns same state instance
 * @param state - redux state
 * @param action - redux action
 * @param resolveReducer - returns reducer based on state key
 * @returns {*} state - new or identical instance based on changes
 */


function calculateNewStateForAllKeys(state, action, resolveReducer) {
  var newState = (0, _mapValues2["default"])(state, function (stateForKey, key) {
    var reducer = resolveReducer(key) || _identity2["default"];

    return reducer(stateForKey, action);
  });

  if ((0, _shallowequal["default"])(state, newState)) {
    return state;
  }

  return newState;
}
/**
 * Calculates new state applying reducer on substate
 * based on provided key if state is not modified
 * returns same state instance
 * @param state - redux state
 * @param action - redux action
 * @param key - select substate to apply reducer
 * @param reducer - redux reducer function
 * @returns {*} state - new or identical instance based on changes
 */


function calculateNewStateForSingleKey(state, action, key, reducer) {
  var stateForKey = state[key];
  var newStateForKey = reducer(stateForKey, action);

  if (stateForKey === newStateForKey) {
    return state;
  }

  return _objectSpread(_objectSpread({}, state), {}, _defineProperty({}, key, newStateForKey));
}

function isTargetAllAction(action) {
  var actionOptions = (0, _actionOptions.getActionOptions)(action);
  return (0, _get2["default"])(actionOptions, TARGET_ALL_OPTION_KEY);
}

function applyToAll(action) {
  return (0, _actionOptions.setActionOption)(action, TARGET_ALL_OPTION_KEY, true);
}

function isTargetAllKey(keyValue) {
  return keyValue === TARGET_ALL_REDUCERS;
}

function mapReducer(keySelector, reducer) {
  validateKeySelector(keySelector);
  return function () {
    var state = arguments.length > 0 && arguments[0] !== undefined ? arguments[0] : {};
    var action = arguments.length > 1 ? arguments[1] : undefined;
    var key = resolveKey(action, keySelector);

    if (!key) {
      return state;
    }

    var targetAllKey = isTargetAllKey(key);
    var targetAllAction = isTargetAllAction(action);

    if (targetAllAction || targetAllKey) {
      return calculateNewStateForAllKeys(state, action, function () {
        return reducer;
      });
    }

    return calculateNewStateForSingleKey(state, action, key, reducer);
  };
}

function mapReducerFactory(keySelector, reducerFactory) {
  var reducers = {};
  validateKeySelector(keySelector);
  return function () {
    var state = arguments.length > 0 && arguments[0] !== undefined ? arguments[0] : {};
    var action = arguments.length > 1 ? arguments[1] : undefined;
    var key = resolveKey(action, keySelector);

    if (!key) {
      return state;
    }

    var targetAllKey = isTargetAllKey(key);
    var targetAllAction = isTargetAllAction(action);

    if (targetAllAction || targetAllKey) {
      return calculateNewStateForAllKeys(state, action, function (stateKey) {
        return reducers[stateKey] || reducerFactory(stateKey);
      });
    }

    reducers[key] = reducers[key] || reducerFactory(key);
    var reducer = reducers[key];
    return calculateNewStateForSingleKey(state, action, key, reducer);
  };
}
/**
 * MapReducers is composer that enables applying reducer on substate that is selected based
 * on key. Key is selected from action based on keySelector. It allows for one reducer to be
 * applied to substate depending on key in action or to dynamically create reducer for each
 * key and apply it on substate.
 * @param keySelector is function that returns key or path to key in action
 * @param reducer can be normal redux reducer or reducer factory. In either way defined or
 * created reducer is applied to part of state under key defined in action. Reducer factory
 * is function that receives key and returns reducer function. In that way enabling to create
 * dynamic reducers for different keys.
 * @returns {Function}
 */


function mapReducers(keySelector, reducer) {
  var result = reducer(undefined, {});

  if ((0, _isFunction2["default"])(result)) {
    return mapReducerFactory(keySelector, reducer);
  }

  return mapReducer(keySelector, reducer);
}