HTML 5 Storage's same origin policy

I've tried with Firefox 4.0 to use the localStor开发者_C百科age object to save a few values used to fill the form at http://host1.example.com/index.html and to fetch those values to automatically fill the same form at http://host2.example.com/index.html but it doesn't work.

Does the same origin policy applies to the url instead of the domain?

No, it applies to hosts. You could try setting document.domain before you create or retrieve your localStorage objects:

document.domain = "example.com";

--edit

OK, though you can set document.domain that has no impact on localStorage. It is possible to hack together a solution using iframe and cross document messaging: Cross-domain localStorage

you're out of luck. localStorage cannot be shared between different domains.

So for example I could set localStorage data at dev.blah.com, and retrieve it from prod.blah.com, as long as I set the document.domain = "blah.com"; ?

You can't use localStorage or sessionStorage cross the domains or sub-domains just with the original API. You can use some libraries to help sending message between different domains.