Re: [widgets] Widgets URI scheme

On Fri, 23 May 2008 13:07:50 +0200, Dan Brickley <> wrote:

> Marcos Caceres wrote:
>> Dear TAG,
>> The WAF working group is seeking advice on the creation of a Widget
>> URI scheme.
> If you really can't live with http: URIs, have you considered using the  
> tag: URI scheme, see

Some considerations here:

1. Widgets, or other locally installed web applications may have multiple  
instances served from an arbitrary origin: Preinstalled on devices, beamed  
over bluetooth/IR, installed from a local file system, or over HTTP. Also
2. In general, the resources do need to resolve, as the DOM attributes are  
resolved, and normalized, so "DSC0201.jpg" - when loaded from the local  
filesystem - becomes for instance file://localhost/path/to/DSC0201.jpg".  
The tag: URI scheme specifically says this:

    Unlike most other URIs, tags can only be used as identifiers, and are  
    designed to support resolution.
3. It is desired to shield the widget from the file system of the runtime  
(e.g. a widget should not be able to discern information about the file  
system by examining files loaded from within the widget.
4. Widgets should not be able to have unchecked access to resources  
outside of itself.  Use of the file: scheme makes this (more) difficult.

Arve Bersvendsen

Developer, Opera Software ASA,

Received on Friday, 23 May 2008 11:53:16 UTC