url hash和html5 history使用

/**
 * HashHistory
 * @link https://zhuanlan.zhihu.com/p/27588422
 */

// hash的改变会自动添加到浏览器的访问历史记录中。
function pushHash (path) {
  window.location.hash = path
}

// replace()方法与push()方法不同之处在于，它并不是将新路由添加到浏览器访问历史的栈顶，而是替换掉当前的路由
function replaceHash (path) {
  const i = window.location.href.indexOf('#')
  window.location.replace(
    window.location.href.slice(0, i >= 0 ? i : 0) + '#' + path
  )
}

// 用户还可以直接在浏览器地址栏中输入改变路由. SO, 可以为hash的改变添加监听事件
// window.addEventListener("hashchange", funcRef, false)

window.addEventListener('hashchange', () => {
  if (!ensureSlash()) {
    return
  }
  this.transitionTo(getHash(), route => {
    replaceHash(route.fullPath)
  })
})

function ensureSlash (): boolean {
  const path = getHash()
  if (path.charAt(0) === '/') {
    return true
  }
  replaceHash('/' + path)
  return false
}

export function getHash (): string {
  const href = window.location.href
  const index = href.indexOf('#')
  return index === -1 ? '' : href.slice(index + 1)
}

/**
 * HTML5History
 * HTML5开始，History interface提供了两个新的方法：pushState(), replaceState() 使得我们可以对浏览器历史记录栈进行修改
 * @link https://zhuanlan.zhihu.com/p/27588422
 */

// 
// stateObject: 当浏览器跳转到新的状态时，将触发popState事件，该事件将携带这个stateObject参数的副本
// title: 所添加记录的标题
// URL: 所添加记录的URL
window.history.pushState(stateObject, title, URL)
window.history.replaceState(stateObject, title, URL)

// src/util/push-state.js
export function pushState (url?: string, replace?: boolean) {
  saveScrollPosition()
  // try...catch the pushState call to get around Safari
  // DOM Exception 18 where it limits to 100 pushState calls
  const history = window.history
  try {
    if (replace) {
      history.replaceState({ key: _key }, '', url)
    } else {
      _key = genKey()
      history.pushState({ key: _key }, '', url)
    }
  } catch (e) {
    window.location[replace ? 'replace' : 'assign'](url)
  }
}

export function replaceState (url?: string) {
  pushState(url, true)
}

// 在HTML5History中添加对修改浏览器地址栏URL的监听
window.addEventListener('popstate', e => {
  const current = this.current
  this.transitionTo(getLocation(this.base), route => {
    if (expectScroll) {
      handleScroll(router, route, current, true)
    }
  })
})

ensureURL (push?: boolean) {
  if (getLocation(this.base) !== this.current.fullPath) {
    const current = cleanPath(this.base + this.current.fullPath)
    push ? pushState(current) : replaceState(current)
  }
}

export function getLocation (base: string): string {
  let path = window.location.pathname
  if (base && path.indexOf(base) === 0) {
    path = path.slice(base.length)
  }
  return (path || '/') + window.location.search + window.location.hash
}