Element树形控件el-tree懒加载并设置默认展开和选中的效果

<el-tree
      :load="loadNode"
      node-key="org_id"
      is-connection-line
      show-checkbox
      lazy
      :default-checked-keys="defaultSelectCids"
      :default-expanded-keys="defaultExpandedCids"
      :props="defaultProps"
      @check-change="handleCheckChange"
      ref="orgTreeData"
    >
      <span class="custom-tree-node" slot-scope="{ node, data }">
        <span>{{ node.label }}</span>
        <span style="padding-left: 10px"> {{ data.in_service.count }} </span>
      </span>
    </el-tree>

dataTree = [];
  defaultProps = {
    children: 'child',
    label: 'org_name',
    isLeaf: data => {
      return !data.has_child;
    },
  };
  defaultExpandedCids = []; // 选出所有pid为0的 cid节点
  defaultSelectCids = []; // 选出所有cid

async loadNode(node, resolve) {
    if (!node.data) {
      const res = await this.getOrg(null);
      if (res && Array.isArray(res)) {
        res.forEach(item => {
          if (item.has_child && item.parent.id === 0) {
            this.defaultExpandedCids.push(item.org_id);
          }
          this.defaultSelectCids.push(item.org_id);
        });
      }
      resolve(res);
    } else {
      resolve(await this.getOrg(node.data.org_id));
    }
  }
  handleCheckChange(data, checked, indeterminate) {
    console.log(data, checked, indeterminate, this.$refs.orgTreeData.getCheckedKeys());
  }
  async getOrg(orgId) {
    
    this.orgTreeLoading = true;
    const {
      data: { tree_data = {} },
      error,
    } = await http.API();
    if (!error) {
      this.orgTreeLoading = false;
      return new Promise(resolve => {
        resolve(tree_data);
      });
    }
  }