轻松实现可扩展的树形表格

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,都没有找的太理想可进行二次开发的开源项目,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

《轻松实现可扩展的树形表格》

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>

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
        }

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;
        }
    原文作者:shenjx
    原文地址: https://segmentfault.com/a/1190000018829745
    本文转自网络文章,转载此文章仅为分享知识,如有侵权,请联系博主进行删除。
点赞