梳理数据---转数型结构

....
this.curriculumTypeData = this.handleData(respond)
...
handleData (data) {
      let allData = this.deepClone(data)
      let l2 = allData.filter(item => { return item.level == '2' })
      let l1 = allData.filter(item => { return item.level == '1' })
      this.classList = this.deepClone(l1)
      this.classList.unshift({ name: '无', id: '' })
      l1.forEach(one => {
        one.children = l2.filter(two => { return one.id == two.parentId })
      })
      return l1
    },
deepClone (obj) {
      return JSON.parse(JSON.stringify(obj))
    },