elm-storage

This module provides a unified interface for accessing and modifying LocalStorage, SessionStorage and Cookies.

Installation

Add gdotdesign/elm-storage to your dependencies:

"dependencies": {
  "gdotdesign/elm-storage": "1.0.0 <= v < 2.0.0"
}

And install with elm-github-install using the elm-install command.

Usage

The following functions are available for Storage.Local, Storage.Session:

-- Asynchronous
get : String -> Task Error (Maybe String)
set : String -> String -> Task Error ()
remove : String -> Task Error ()
keys : Task Error (List String)
length : Task Error Int
clear : Task Error ()

-- Synchronous
getSync : String -> Result Error (Maybe String)
setSync : String -> String -> Result Error ()
keysSync : () -> Result Error (List String)
removeSync : String -> Result Error ()
length : () -> Result Error Int
clear : () -> Result Error ()

and a slightly different version for Storage.Cookie:

-- Asynchronous
set : String -> String -> SetOptions -> Task Error ()
remove : String -> RemoveOptions -> Task Error ()
get : String -> Task Error (Maybe String)
clear : RemoveOptions -> Task Error ()
keys : Task Error (List String)
length : Task Error Int

-- Synchronous
setSync : String -> String -> SetOptions -> Result Error ()
removeSync : String -> RemoveOptions -> Result Error ()
getSync : String -> Result Error (Maybe String)
keysSync : () -> Result Error (List String)
clear : RemoveOptions -> Result Error ()
length : () -> Result Error Int

-- Options
type alias SetOptions =
  { domain : String
  , expires : Float
  , secure : Bool
  , path : String
  }

type alias RemoveOptions =
  { domain : String
  , path : String
  }

Testing

The module contains steps and assertions to use with elm-spec. Check out the specs on how to use them, and here is a quick example:

import Spec exposing (..)

import Storage.Spec.Local exposing (localStorage)

tests : Node
tests =
  describe "Local Storage"
    [ it "should be testable"
      [ localStorage.clear
      , localStorage.set "user" "yoda"
      , localStorage.hasItem "user"
      , localStorage.valueEquals "user" "yoda"
      , localStorage.haveNumberOfItems 1
      , localStorage.haveItems ["user"]
      ]
    ]

main =
  run tests