由于ElementUI目前还未开发树形表格组件,也参阅了网络上部分基于ElementUI表格封装的开源树形组件,如果想进行二次开发的话都不太理想,所以就萌生了自行开发树形表格。
本示例提供开发思路,移除了多余的样式,比较适合新手入门学习,如果应用于实际项目还请自行封装。
目前还仅仅实现了视觉的树结构的层级效果和控制结构的显示隐藏,后续还会进行不断的完善和优化,有必要的话会对组件进行二次封装,有点在重复造论的感觉哈。
效果图
完整代码
页面(tree-table.vue)
<template>
<div>
TreeTable
<el-table :data="list" :row-style="tableRowStyle" border>
<el-table-column type="selection" width="55"></el-table-column>
<el-table-column prop="id" label="ID" width="180">
<template slot-scope="scope">
<span class="collapse"
:class="collapseClass(scope.row)"
:style="tableRowPaddingStyle(scope.row)"
@click="handleCollapseClick(scope.row)">
</span>
<span>{{ scope.row.id }}</span>
</template>
</el-table-column>
<el-table-column prop="name" label="NAME"></el-table-column>
</el-table>
</div>
</template>
<script lang="ts">
import {Component, Vue} from 'vue-property-decorator'
// 引入两个封装好的工具方法
import { arrayToTree } from './utils/array.js'
import { ergodicTree } from './utils/tree.js'
@Component
export default class TreeTable extends Vue {
private list: object[] = [];
private tree: object[] = [];
created() {
// 准备一组含有父子级关系的一维数组方便示例测试
// 在实际项目应用中,理应通过后端接口返回
let _list = [
{
id: 'a',
pid: '',
name: '部门a',
children: []
},
{
id: 'a1',
pid: 'a',
name: '子部门a1',
children: []
},
{
id: 'a2',
pid: 'a',
name: '子部门a2',
children: []
},
{
id: 'a2-1',
pid: 'a2',
name: '子部门a2-1',
children: []
},
{
id: 'a2-2',
pid: 'a2',
name: '子部门a2-2',
children: []
},
{
id: 'a3',
pid: 'a',
name: '子部门a3',
children: []
},
{
id: 'a3-1',
pid: 'a3',
name: '子部门a3-1',
children: []
},
{
id: 'b',
pid: '',
name: '部门b',
children: []
},
{
id: 'b1',
pid: 'b',
name: '子部门b1',
children: []
},
{
id: 'c',
pid: '',
name: '部门c',
children: []
},
];
// 将一维数组转成树形结构并存储于tree变量
this.tree = arrayToTree(_list);
// 考虑到实际应用过程中接口返回的数据是无序的,所以我们对tree进行先序遍历将节点一一插入到list变量
this.list = [];
ergodicTree(this.tree, (node: any) => {
this.list.push(node);
// 遍历过程中并对每个节点挂载open和show属性
// open:控制节点的打开和关闭
// show:控制节点的显示和隐藏
this.$set(node, 'open', true);
this.$set(node, 'show', true)
})
}
// 控制行的显示和隐藏
tableRowStyle(scope: any) {
return {
'display': scope.row.show ? '' : 'none'
}
}
// 通过每个节点的深度,设置行的缩进实现视觉上的层级效果
tableRowPaddingStyle(row: any) {
return {
'margin-left': `${(row._depth - 1) * 24}px`
}
}
// 控制展开按钮的展开和关闭状态
collapseClass(row: any) {
return {
'collapse--open': row.open == false && row.children && row.children.length > 0,
'collapse--close': row.open == true && row.children && row.children.length > 0
}
}
// 处理展开按钮的点击事件
handleCollapseClick(row: any) {
const _open = row.open;
// 通过节点访问路径控制节点的显示隐藏,由于内存指针的关系list和tree的节点操作都会相互影响
ergodicTree(this.tree, (node: any) => {
node._idPath.forEach((pathId: any) => {
if (pathId == row.id) {
this.$set(node, 'show', !_open);
this.$set(node, 'open', !_open)
}
})
});
row.show = true;
row.open = !_open;
}
}
</script>
<style lang="scss" scoped>
.collapse {
display: inline-block;
width: 8px;
cursor: pointer;
margin-right: 8px;
}
.collapse--open:before {
content: '+';
}
.collapse--close:before {
content: '-';
}
</style>
复制代码
工具方法
考虑数组转树和遍历树都是在实际项目中都是非常常用的,所以这边对这两个方法进行了封装。
数组转树结构(./utils/array.ts)
export function arrayToTree(list: object[], props = {id: 'id', pid: 'pid', children: 'children'}) {
let tree: object[] = [];
let map: any = {};
let listLength = list.length;
for (let i = 0; i < listLength; i++) {
let node: any = list[i];
let nodeId: any = node[props.id];
map[nodeId] = node;
}
for (let i = 0; i < listLength; i++) {
let node: any = list[i];
let nodePid: any = node[props.pid];
let parentNode: any = map[nodePid];
if (parentNode) {
parentNode[props.children] = parentNode[props.children] || [];
parentNode[props.children].push(node)
} else {
tree.push(node)
}
}
return tree
}
复制代码
遍历树结构(./utils/tree.ts)
结合实际项目应用,我们采用了先序遍历法对树进行遍历,为了方便在业务代码里的应用,在遍历过程中会对每个节点挂载节点访问路径 _idPath 属性和节点深度 _depth 属性。
export function ergodicTree(tree: object[], callback: any = () => {}, props = {id: 'id', pid: 'pid', children: 'children'}) {
function _ergodicTree(tree: object[], parentIdPath?: any[], depth: number = 0) {
const treeLength = tree.length;
for (let i = 0; i < treeLength; i++) {
let node: any = tree[i];
const _idPath: any[] = parentIdPath ? [...parentIdPath, node[props.id]] : [node[props.id]];
const _depth: number = depth + 1;
node._idPath = _idPath;
node._depth = _depth;
callback(node);
if (node[props.children] && node[props.children] instanceof Array) {
_ergodicTree(node[props.children], _idPath, _depth)
}
}
}
_ergodicTree(tree);
return tree;
}
复制代码