小例子-组织树加上右键菜单添加删除组织，vue2，el-tree

<template>
  <div>
    <el-tree
      :data="treeData"
      node-key="id"
      :props="defaultProps"
      @node-contextmenu="openMenu"
      @node-click="handleNodeClick"
    >
      <!-- Custom tree node -->
      <span class="custom-tree-node" slot-scope="{ node, data }">
        <span>{{ node.label }}</span>
        <span>
          <el-button
            type="text"
            size="mini"
            @click="() => append(data)"
          >
            添加
          </el-button>
          <el-button
            type="text"
            size="mini"
            @click="() => remove(node, data)"
          >
            删除
          </el-button>
        </span>
      </span>
    </el-tree>

    <!-- Context menu -->
    <div
      v-show="menuVisible"
      :style="{ top: menuTop + 'px', left: menuLeft + 'px' }"
      class="contextmenu"
    >
      <el-button @click="add">添加</el-button>
      <el-button @click="del">删除</el-button>
    </div>
  </div>
</template>

<script>
export default {
  data() {
    return {
      menuVisible: false,
      menuTop: 0,
      menuLeft: 0,
      treeData: [
        {
          id: 1,
          label: '组织1',
          children: [
            {
              id: 2,
              label: '组织1-1'
            }
          ]
        }
      ],
      defaultProps: {
        children: 'children',
        label: 'label'
      }
    };
  },
  methods: {
    openMenu(event, data, node, element) {
      this.menuVisible = true;
      this.menuTop = event.clientY;
      this.menuLeft = event.clientX;
    },
    handleNodeClick(data) {
      console.log(data);
    },
    append(data) {
      const newChild = { id: id++, label: `组织${id}`, children: [] };
      if (!data.children) {
        this.$set(data, 'children', []);
      }
      data.children.push(newChild);
    },
    remove(node, data) {
      const parent = node.parent;
      const children = parent.data.children || parent.data;
      const index = children.findIndex(d => d.id === data.id);
      children.splice(index,