[whatwg] sessionStorage and the Storage event

[Ian Hickson]

On Tue, 27 Oct 2009, Honza Bambas wrote:
>
> The spec says:
> 
> "When the |setItem()
> <http://dev.w3.org/html5/webstorage/#dom-storage-setitem>|, |removeItem()
> <http://dev.w3.org/html5/webstorage/#dom-storage-removeitem>|, and |clear()
> <http://dev.w3.org/html5/webstorage/#dom-storage-clear>| methods are called on
> a |Storage <http://dev.w3.org/html5/webstorage/#storage-0>| object x that is
> associated with a session storage area, if the methods did something, then in
> every |HTMLDocument| object whose |Window| object's |sessionStorage
> <http://dev.w3.org/html5/webstorage/#dom-sessionstorage>| attribute's |Storage
> <http://dev.w3.org/html5/webstorage/#storage-0>| object is associated with the
> same storage area, other than x, a |storage
> <http://dev.w3.org/html5/webstorage/#event-storage>| event must be fired, as
> described below <http://dev.w3.org/html5/webstorage/#event-storage>."
> 
> [http://dev.w3.org/html5/webstorage/#dom-sessionstorage]
> 
> The same applies to localStorage.
> 
> Maybe I read something wrong, but as a sessionStorage object is always 
> unique to its document (it is cloned when a new document with the same 
> origin is created and then independent from the original document's 
> object) it, in my opinion, doesn't make sense to send the event to any 
> other document then the one its storage has been changed. On the other 
> hand, it makes sense to me to not fire the event in the same document 
> where the storage has been changed (as for localStorage), then, I'd say 
> there should be no event for sessionStorage at all. I simply don't a 
> case when two or more documents would share a single sessionStorage 
> object.
> 
> Thanks for clearing this.

You can have multiple (active) documents sharing the same sessionHistory 
using nested browsing contexts, for example in <iframe>, <object>, and 
<frameset>/<frame>.

-- 
Ian Hickson               U+1047E                )\._.,--....,'``.    fL
http://ln.hixie.ch/       U+263A                /,   _.. \   _\  ;`._ ,.
Things that are impossible just take longer.   `._.-(,_..'--(,_..'`-.;.'