jsonArray 转 tree

/**
 * * @param data 入口参数data,平行数组
  * @param key id字段
  * @param parentKey 父字段
  * @param map 需要将原始属性名称转换为什么名称 {"text":"title","id":"id0"};
 */export  default  function (data, key, parentKey, map) {
  this.data = data;
  this.key = key;
  this.parentKey = parentKey;
  this.treeParentKey = parentKey; //parentKey要转换成什么属性名称
  this.treeKey = key; //key要转换成什么属性名称
  this.map = map;
  if (map) {
  if (map[key]) this.treeKey = map[key];
  }
  /**
 * 转成tree
 * @returns {Array}
 */  this.toTree = function () {
  let data = this.data;
  let pos = {};
  let tree = [];
  let i = 0;
  while (data.length !== 0) {
  if (data[i][this.parentKey] === 0) {
  let _temp = this.copy(data[i]);
  tree.push(_temp);
  pos[data[i][this.key]] = [tree.length - 1];
  data.splice(i, 1);
  i--;
  } else {
  let posArr = pos[data[i][this.parentKey]];
  if (posArr !== undefined) {
  let obj = tree[posArr[0]];
  for (let j = 1; j < posArr.length; j++) {
  obj = obj.children[posArr[j]];
  }
  let _temp = this.copy(data[i]);
  obj.children.push(_temp);
  pos[data[i][this.key]] = posArr.concat([obj.children.length - 1]);
  data.splice(i, 1);
  i--;
  }
 }  i++;
  if (i > data.length - 1) {
  i = 0;
  }
 }  return tree;
  };
  /**
 * 拷贝
  * @param item
 * @returns {{children: Array}}
 */  this.copy = function (item) {
  let _temp = {
  children: []
 };
  _temp[this.treeKey] = item[this.key];
  for (let _index in item) {
  if (_index !== this.key && _index !== this.parentKey) {
  let _property = item[_index];
  if ((!!this.map) && this.map[_index])
  _temp[this.map[_index]] = _property;
  else
  _temp[_index] = _property;
  }
 }  return _temp;
  }
}