ブラウザのローカルで I/O めも

root = @
$.cookie.json = true

storage = root.storage = (strageType) -> 
  switch strageType
    when 'localstorage'
      return {
        setItem: (key, val) -> 
          if arguments.length < 2
            return throw new Error('arguments number is not enough.')
          if not _.isString(val)
            val = JSON.stringify(val)
          localStorage.setItem(key, val)
        getItem: (key) ->
          data = localStorage.getItem(key)
          try
            parseData = JSON.parse(data)
            return parseData
          catch
            return data
        removeItem: (key) -> localStorage.removeItem(key)
      }
    when 'cookie'
      return {
        period: 7
        setItem: (key, val) -> 
          if arguments.length < 2
            return throw new Error('arguments number is not enough.')
          $.cookie(key, val, {expires: period, path: '/'})
        getItem: (key) -> return $.cookie(key)
        removeItem: (key) -> $.removeCookie(key)
      }
    else
      throw new Error('this strageType is invalid.')

## localStorage に user キーでデータを保存
db = storage('localstrage')
db.setItem('user', {'id': 1, 'u_name': 'foo', 'u_items': [1,2,0,3]})

## 取り出し
db.getItem('user')  
## object 型で取り出される
## {'id': 1, 'u_name': 'foo', 'u_items': [1,2,0,3]}

## 削除
db.removeItem('user')

## Boolean 型
db.setItem('flg', true)
db.getItem('flg')

## Number 型で取り出し
db.setItem('counter', 10)
db.getItem('counter')

## cookie を使う
db = storage('cookie')
## 有効期限を 10 日とする.
db.period = 10