转换后台传来的tree格式

后台返回的格式是parentId+id,children:[],可以忽略，需要前端手动转化成children是嵌套的elementui的标准格式

• 非ts和eslint模式，如果开启eslint，还需修改一些配置如== 等

/**
 * 构造树型结构数据
 * @param {*} data 数据源
 * @param {*} id id字段 默认 'id'
 * @param {*} parentId 父节点字段 默认 'parentId'
 * @param {*} children 孩子节点字段 默认 'children'
 */
export function handleTree(data, id, parentId, children) {
	let config = {
		id: id || 'id',
		parentId: parentId || 'parentId',
		childrenList: children || 'children'
	};

	var childrenListMap = {};
	var nodeIds = {};
	var tree = [];

	for (let d of data) {
		let parentId = d[config.parentId];
		if (childrenListMap[parentId] == null) {
			childrenListMap[parentId] = [];
		}
		nodeIds[d[config.id]] = d;
		childrenListMap[parentId].push(d);
	}

	for (let d of data) {
		let parentId = d[config.parentId];
		if (nodeIds[parentId] == null) {
			tree.push(d);
		}
	}

	for (let t of tree) {
		adaptToChildrenList(t);
	}

	function adaptToChildrenList(o) {
		if (childrenListMap[o[config.id]] !== null) {
			o[config.childrenList] = childrenListMap[o[config.id]];
		}
		if (o[config.childrenList]) {
			for (let c of o[config.childrenList]) {
				adaptToChildrenList(c);
			}
		}
	}
	return tree;
}

在vue的element项目中使用main.js中配置

import { handleTree } from "@/utils/xxxx";

// 全局方法挂载
Vue.prototype.handleTree = handleTree

//调用handletree，把格式改为children嵌套的符合element的格式；
fetch('http://localhost:3000/9.json').then(res=>res.json()).then(response=>{
        this.deptList = this.handleTree(response.data, "deptId");
        this.loading = false;
})