semantic-ui-react/dist/commonjs/modules/Transition/utils/childMapping.js

The official Semantic-UI-React integration.

"use strict";

var _interopRequireDefault = require("@babel/runtime/helpers/interopRequireDefault");

exports.__esModule = true;
exports.mergeChildMappings = exports.getChildMapping = void 0;

var _has2 = _interopRequireDefault(require("lodash/has"));

var _keys2 = _interopRequireDefault(require("lodash/keys"));

var _forEach2 = _interopRequireDefault(require("lodash/forEach"));

var _filter2 = _interopRequireDefault(require("lodash/filter"));

var _keyBy2 = _interopRequireDefault(require("lodash/keyBy"));

var _react = require("react");

/**
 * Given `this.props.children`, return an object mapping key to child.
 *
 * @param {object} children Element's children
 * @return {object} Mapping of key to child
 */
var getChildMapping = function getChildMapping(children) {
  return (0, _keyBy2.default)((0, _filter2.default)(_react.Children.toArray(children), _react.isValidElement), 'key');
};

exports.getChildMapping = getChildMapping;

var getPendingKeys = function getPendingKeys(prev, next) {
  var nextKeysPending = {};
  var pendingKeys = [];
  (0, _forEach2.default)((0, _keys2.default)(prev), function (prevKey) {
    if (!(0, _has2.default)(next, prevKey)) {
      pendingKeys.push(prevKey);
      return;
    }

    if (pendingKeys.length) {
      nextKeysPending[prevKey] = pendingKeys;
      pendingKeys = [];
    }
  });
  return [nextKeysPending, pendingKeys];
};

var getValue = function getValue(key, prev, next) {
  return (0, _has2.default)(next, key) ? next[key] : prev[key];
};
/**
 * When you're adding or removing children some may be added or removed in the same render pass. We want to show *both*
 * since we want to simultaneously animate elements in and out. This function takes a previous set of keys and a new set
 * of keys and merges them with its best guess of the correct ordering.
 *
 * @param {object} prev Prev children as returned from `getChildMapping()`
 * @param {object} next Next children as returned from `getChildMapping()`
 * @return {object} A key set that contains all keys in `prev` and all keys in `next` in a reasonable order
 */


var mergeChildMappings = function mergeChildMappings(prev, next) {
  if (prev === void 0) {
    prev = {};
  }

  if (next === void 0) {
    next = {};
  }

  var childMapping = {};

  var _getPendingKeys = getPendingKeys(prev, next),
      nextKeysPending = _getPendingKeys[0],
      pendingKeys = _getPendingKeys[1];

  (0, _forEach2.default)((0, _keys2.default)(next), function (nextKey) {
    if ((0, _has2.default)(nextKeysPending, nextKey)) {
      (0, _forEach2.default)(nextKeysPending[nextKey], function (pendingKey) {
        childMapping[pendingKey] = getValue(pendingKey, prev, next);
      });
    }

    childMapping[nextKey] = getValue(nextKey, prev, next);
  });
  (0, _forEach2.default)(pendingKeys, function (pendingKey) {
    childMapping[pendingKey] = getValue(pendingKey, prev, next);
  });
  return childMapping;
};

exports.mergeChildMappings = mergeChildMappings;