src/core/util/dom.js

import { isFn } from '../util/core'

const cacheNode = {}

/**
 * Get Node
 * @param  {String|Element} el
 * @param  {Boolean} noCache
 * @return {Element}
 */
export function getNode (el, noCache = false) {
  if (typeof el === 'string') {
    if (typeof window.Vue !== 'undefined') {
      return find(el)
    }
    el = noCache ? find(el) : (cacheNode[el] || (cacheNode[el] = find(el)))
  }

  return el
}

export const $ = document

export const body = $.body

export const head = $.head

/**
 * Find element
 * @example
 * find('nav') => document.querySelector('nav')
 * find(nav, 'a') => nav.querySelector('a')
 */
export function find (el, node) {
  return node ? el.querySelector(node) : $.querySelector(el)
}

/**
 * Find all elements
 * @example
 * findAll('a') => [].slice.call(document.querySelectorAll('a'))
 * findAll(nav, 'a') => [].slice.call(nav.querySelectorAll('a'))
 */
export function findAll (el, node) {
  return [].slice.call(node ? el.querySelectorAll(node) : $.querySelectorAll(el))
}

export function create (node, tpl) {
  node = $.createElement(node)
  if (tpl) node.innerHTML = tpl
  return node
}

export function appendTo (target, el) {
  return target.appendChild(el)
}

export function before (target, el) {
  return target.insertBefore(el, target.children[0])
}

export function on (el, type, handler) {
  isFn(type)
    ? window.addEventListener(el, type)
    : el.addEventListener(type, handler)
}

export function off (el, type, handler) {
  isFn(type)
    ? window.removeEventListener(el, type)
    : el.removeEventListener(type, handler)
}

/**
 * Toggle class
 *
 * @example
 * toggleClass(el, 'active') => el.classList.toggle('active')
 * toggleClass(el, 'add', 'active') => el.classList.add('active')
 */
export function toggleClass (el, type, val) {
  el && el.classList[val ? type : 'toggle'](val || type)
}