Access this.$bvmodal from Vue 2.7 setup syntax

use-modal.ts

/**
 * Usage:
 * const { msgBoxConfirm } = useModal();
 */

import { getCurrentInstance } from 'vue'

export function useModal () {
  const { proxy } = getCurrentInstance() ?? {}
  if (!proxy) {
    throw new Error('No instance in context')
  }
  
  const $bvModal = proxy.$bvModal

  if (!$bvModal) {
    throw new Error('No $bvModal in context')
  }

  const createElement = getCurrentInstance()?.proxy.$createElement
  if (!createElement) {
    throw new Error('No $createElement in context')
  }

  const {
    hide,
    msgBoxConfirm,
    msgBoxOk,
    show
  } = $bvModal

  if (!hide || !msgBoxConfirm || !msgBoxOk || !show) {
    throw new Error('Incomplete $bvModal in context')
  }

  return { 
    hide: hide.bind($bvModal), 
    msgBoxConfirm: msgBoxConfirm.bind($bvModal), 
    msgBoxOk: msgBoxOk.bind($bvModal), 
    show: show.bind($bvModal), 
    createElement: createElement.bind(proxy)
  }
}