import PropTypes from '../../_util/vue-types'

export default {
  props: {
    children: PropTypes.func.def(() => null),
  },
  methods: {
    getRef (name) {
      return this[name]
    },

    saveRef (name) {
      return (node) => {
        if (node) {
          this[name] = node
        }
      }
    },
  },

  render () {
    // 每次都new一个新的function，避免子节点不能重新渲染
    const saveRef = (name) => this.saveRef(name)
    const getRef = (name) => this.getRef(name)
    return this.children(saveRef, getRef)
  },
}