@antv/f2/es/children.js

import _objectSpread from "@babel/runtime/helpers/esm/objectSpread2";
import { isArray, isNil } from '@antv/util';

function cloneElement(element, props) {
  if (!element) return element;
  return _objectSpread(_objectSpread({}, element), {}, {
    props: _objectSpread(_objectSpread({}, element.props), props)
  });
}

function map(children, fn) {
  if (!children) {
    return fn(children);
  }

  if (isArray(children)) {
    return children.map(function (child) {
      return map(child, fn);
    });
  }

  return fn(children);
}

function compareArray(nextElements, lastElements, callback) {
  var keyed = {};
  var nextLength = nextElements.length;
  var lastLength = lastElements.length;

  for (var i = 0, len = lastLength; i < len; i++) {
    var element = lastElements[i];

    if (element && !isNil(element.key)) {
      var key = element.key;
      keyed[key] = element;
    }
  } // 比较元素


  for (var _i = 0, _len = Math.max(nextLength, lastLength); _i < _len; _i++) {
    var _element = nextElements[_i];

    if (!_element) {
      compare(_element, lastElements[_i], callback);
      continue;
    }

    var _key = _element.key; // 有key值定义

    if (!isNil(_element.key)) {
      var lastElement = keyed[_key];
      if (lastElement) delete keyed[_key];
      compare(_element, lastElement, callback);
      continue;
    }

    compare(_element, lastElements[_i], callback);
  } // 说明是删除的元素


  Object.keys(keyed).forEach(function (key) {
    compare(null, keyed[key], callback);
  });
} // 比较2棵树


function compare(nextElement, lastElement, callback) {
  // 有一个为空
  if (!nextElement || !lastElement) {
    callback(nextElement, lastElement);
    return;
  }

  if (isArray(nextElement) || isArray(lastElement)) {
    var nextElementArray = isArray(nextElement) ? nextElement : [nextElement];
    var lastElementArray = isArray(lastElement) ? lastElement : [lastElement];
    compareArray(nextElementArray, lastElementArray, callback);
    return;
  }

  callback(nextElement, lastElement);
}

function toArray(element) {
  if (!element) {
    return element;
  }

  if (!isArray(element)) {
    return [element];
  }

  var newArray = [];

  for (var i = 0, len = element.length; i < len; i++) {
    var item = element[i];

    if (isArray(item)) {
      // @ts-ignore
      newArray = newArray.concat(toArray(item));
    } else {
      newArray.push(item);
    }
  }

  return newArray;
}

var Children = {
  cloneElement: cloneElement,
  map: map,
  toArray: toArray,
  compare: compare
};
export default Children;