storage.js

/*
* @Author: baosheng
* @Date:   2018-04-02 22:28:51
* @Last Modified by:   baosheng
* @Last Modified time: 2018-04-02 22:32:17
*/
const storage = { version: '1.3.17' }

storage.has = key => storage.get(key) !== undefined

storage.transact = (key, defaultVal, transactionFn) => {
  let val = ''

  if (transactionFn === null) {
    transactionFn = defaultVal
    defaultVal = null
  }
  if (defaultVal === null) {
    defaultVal = {}
  }
  val = storage.get(key, defaultVal)
  transactionFn(val)
  storage.set(key, val)
}

storage.serialize = value => JSON.stringify(value)
storage.deserialize = value => {
  if (typeof value !== 'string') { return undefined }
  try {
    return JSON.parse(value)
  } catch (e) {
    return value || undefined
  }
}

storage.set = (key, val) => {
  if (val === undefined) { return storage.remove(key) }
  localStorage.setItem(key, storage.serialize(val))
  return val
}
storage.get = (key, defaultVal) => {
  const val = storage.deserialize(localStorage.getItem(key))

  return (val === undefined ? defaultVal : val)
}
storage.remove = key => localStorage.removeItem(key)
storage.clear = () => localStorage.clear()
storage.getAll = () => {
  const ret = {}

  storage.forEach((key, val) => {
    ret[key] = val
  })
  return ret
}
storage.forEach = callback => {
  let i = 0
  let key = ''

  for (i = 0; i < localStorage.length; i++) {
    key = localStorage.key(i)
    callback(key, storage.get(key))
  }
}

export default storage