add-slots.js

// @flow

import { compileToFunctions } from 'vue-template-compiler'

function startsWithTag (str) {
  return str && str.trim()[0] === '<'
}

function createVNodesForSlot (
  h: Function,
  slotValue: SlotValue,
  name: string
): VNode | string {
  if (typeof slotValue === 'string' &&
  !startsWithTag(slotValue)) {
    return slotValue
  }

  const el = typeof slotValue === 'string'
    ? compileToFunctions(slotValue)
    : slotValue

  const vnode = h(el)
  vnode.data.slot = name
  return vnode
}

export function createSlotVNodes (
  h: Function,
  slots: SlotsObject
): Array<VNode | string> {
  return Object.keys(slots).reduce((acc, key) => {
    const content = slots[key]
    if (Array.isArray(content)) {
      const nodes = content.reduce((accInner, slotDef) => {
        return accInner.concat(createVNodesForSlot(h, slotDef, key))
      }, [])
      return acc.concat(nodes)
    } else {
      return acc.concat(createVNodesForSlot(h, content, key))
    }
  }, [])
}