TAG Comment on

This is a comment from the W3C Technical Architecture Group on the last 
call working draft: "Web Storage" [1].

The HTML5 Application Cache (AppCache) [2] and Local Storage [1] both 
provide client-side storage that can be used by Web Applications. Although 
the interfaces are different (AppCache has an HTML interface while Local 
Storage has a JavaScript API), and they do seem to have been designed with 
different use cases in mind, they provide somewhat related facilities: both 
cause persistent storage for an application to be created, accessed and 
managed locally at the client. If, for example, the keys in Local Storage 
were interpreted as URIs then Local Storage could be used to store manifest 
files and Web Applications could be written to look transparently for 
manifest files in either the AppCache or in Local Storage. One might also 
envision common facilities for querying the size of or releasing all of the 
local storage for a given application.

At the Offline Web Applications Workshop on Nov 5, 2011 [3] there was a 
request for a JavaScript API for AppCache and talk about coordinating 
AppCache and Local Storage.

The TAG believes it is important to consider more carefully the potential 
advantages of providing a single facility to cover the use cases, of 
perhaps modularizing the architecture so that some parts are shared, or if 
separate facilities are indeed the best design, providing common data 
access and manipulation APIs. If further careful analysis suggests that no 
such integration is practical, then, at a minimum, each specification 
should discuss how it is positioned with respect to the other.

Noah Mendelsohn
For the: W3C Technical Architecture Group

[1] http://www.w3.org/TR/2011/WD-webstorage-20111025/
[2] http://www.w3.org/TR/html5/offline.html#appcache
[3] http://www.w3.org/2011/web-apps-ws/

Received on Tuesday, 15 November 2011 22:06:05 UTC