<template>
  <div>
    <div class="custom-tree-container">
      <div class="block">
        <el-tree
          :data="data"
          show-checkbox
          node-key="id"
          default-expand-all
          :expand-on-click-node="false"
          :render-content="renderContent"
        ></el-tree>
      </div>
    </div>
    
  </div>
</template>
<script>
let id = 1000;
export default {
  data()
  {
    const data = [{
      id: 1,
      label: '一级 1',
      children: [{
        id: 4,
        label: '二级 1-1',
        children: [{
          id: 9,
          label: '三级 1-1-1'
        }, {
          id: 10,
          label: '三级 1-1-2'
        }]
      }]
    }, {
      id: 2,
      label: '一级 2',
      children: [{
        id: 5,
        label: '二级 2-1'
      }, {
        id: 6,
        label: '二级 2-2'
      }]
    }, {
      id: 3,
      label: '一级 3',
      children: [{
        id: 7,
        label: '二级 3-1'
      }, {
        id: 8,
        label: '二级 3-2'
      }]
    }];
    return {
      
      data: JSON.parse(JSON.stringify(data)),
      data: JSON.parse(JSON.stringify(data))
    }
  },
  methods: {
    append(data)
    {
      const newChild = { id: id++, label: 'testtest', 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, 1);
    },

    renderContent(h, { node, data, store })
    {
      return (
        <span class="custom-tree-node">
          <span>{ node.label }</span>
          <span>
            <el-button size="mini" type="text" on-click={ () => this.append(data) }>Append</el-button>
            <el-button size="mini" type="text" on-click={ () => this.remove(node, data) }>Delete</el-button>
          </span>
        </span>);
    }
  }
}
</script>
<style lang="css" scoped>
.custom-tree-node {
  flex: 1;
  display: flex;
  align-items: center;
  justify-content: space-between;
  font-size: 14px;
  padding-right: 8px;
}
</style>