store.js exposes a simple API for cross browser local storage

// Store 'marcus' at 'username'
store.set('username', 'marcus')

// Get 'username'
store.get('username')

// Remove 'username'
store.remove('username')

// Clear all keys
store.clear()

// Store an object literal - store.js uses JSON.stringify under the hood
store.set('user', { name: 'marcus', likes: 'javascript' })

// Get the stored object - store.js uses JSON.parse under the hood
var user = store.get('user')
alert(user.name + ' likes ' + user.likes)

store.js depends on JSON for serialization.

This fork of marcuswestin's store.js aims at working around IE6 and IE7 "same directory" policy. To do so, the plugin is loaded from a page (usually) hosted at the root of your website, by an iframe.

The code to use to load the plugin is the following:

<!--[if lt IE 8 ]>
<iframe frameborder="0" width="0" height="0" src="/store.iframe.html"></iframe>
<![endif]-->
<!--[if (gte IE 8)|!(IE)]><!--> 
<script src="http://ajax.cdnjs.com/ajax/libs/json2/20110223/json2.js"></script>
<script src="store.js"></script>
<!--<![endif]-->

This has the following consequences:

• the "same folder" policy is no longer a problem,
• splitting the plugin into browser-specific parts results in a smaller filesize,
• the store.iframe.html file has to be hosted on the same domain as your pages (CDNs are not an option),
• it is harder to load the script using a script loader (but probably possible with some tweaks).

The IE6/7 part of the plugin doesn't have to be loaded from the root of your website. Loading it from any level in the folder hierarchy makes it possible for pages in subfolders to access the same items.

Storage size in IE6 and IE7 is still limited to 128KB, see http://msdn.microsoft.com/en-us/library/ms531424%28v=VS.85%29.aspx

store.js uses localStorage when available, and falls back on globalStorage for earlier versions of Firefox and the userData behavior in IE6 and IE7. No flash to slow down your page load. No cookies to fatten your network requests.

localStorage, when used without store.js, calls toString on all stored values. This means that you can't conveniently store and retrieve numbers, objects or arrays:

localStorage.myage = 24
localStorage.myage != 24
localStorage.myage == '24'

localStorage.user = { name: 'marcus', likes: 'javascript' }
localStorage.user == "[object Object]"

localStorage.tags = ['javascript', 'localStorage', 'store.js']
localStorage.tags.length == 32
localStorage.tags == "javascript,localStorage,store.js"

What we want (and get with store.js) is

store.set('myage', 24)
store.get('myage') == 24

store.set('user', { name: 'marcus', likes: 'javascript' })
alert("Hi my name is " + store.get('user').name + "!")

store.set('tags', ['javascript', 'localStorage', 'store.js'])
alert("We've got " + store.get('tags').length + " tags here")

The native serialization engine of javascript is JSON. Rather than leaving it up to you to serialize and deserialize your values, store.js uses JSON.stringify() and JSON.parse() on each call to store.set() and store.get(), respectively.

Some browsers do not have native support for JSON. For those browsers you should include JSON.js (non-minified copy is included in this repo).

Go to test.html in your browser

• Tested in Firefox 2.0
• Tested in Firefox 3.0
• Tested in Firefox 3.5
• Tested in Firefox 3.6
• Tested in Chrome 5
• Tested in Safari 4
• Tested in Safari 5
• Tested in IE6
• Tested in IE7
• Tested in IE8
• Tested in Opera 10
• Opera 10.54

• Chrome 4
• Opera 10.10

• Firefox 1.0: no means (beside cookies and flash)
• Safari 2: no means (beside cookies and flash)
• Safari 3: no synchronous api (has asynch sqlite api, but store.js is synch)
• Opera 9: don't know if there is synchronous api for storing data locally
• Firefox 1.5: don't know if there is synchronous api for storing data locally

• original repository: https://github.com/marcuswestin/store.js
• Sans JSON support (simple key/values only): https://github.com/cloudhead/store.js
• jQueryfied version: https://github.com/whitmer/store.js
• Lint.js passing version (with semi-colons): https://github.com/StevenBlack/store.js

• I believe underlying APIs can throw under certain conditions. Where do we need try/catch?
• Test different versions of Opera 10.X explicitly