RE: URI schemes - is widget: OK, but xri: not?

Hello Marty,

> Does the TAG consider a new scheme for widget: to be justified?

Personal opinion for my part is "no". Personnally I am not convinced that a URI scheme for wigets is the correct approach. I think that my responses on that topic [1,2,3] have been fairly consistent about that.

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> -----Original Message-----
> From: []
> On Behalf Of Schleiff, Marty
> Sent: 07 August 2008 23:08
> To:
> Subject: URI schemes - is widget: OK, but xri: not?
> Hi All,
> I haven't seen any messages complaining about a URI scheme
> for widget:. I've seen plenty of messages complaining about a
> URI scheme for xri:.
> Does the TAG consider a new scheme for widget: to be justified?
> If so, then could someone please explain why a widget: scheme
> is justifiable, but an xri: scheme is not?
> Thanks,
> Associate Technical Fellow - Cyber Identity Specialist
> Information Security - Technical Controls
> (206) 679-5933
> -----Original Message-----
> From: Marcos Caceres []
> Sent: Thursday, August 07, 2008 1:20 AM
> To: Krzysztof Maczyński; Williams, Stuart (HP Labs, Bristol);
> Subject: Re: Comments on Widgets 1.0: Requirements LCWD
> Hi Stuart, All,
> This email is a continuation of the discussion about the
> Widget URI scheme we've had in the past [1]. WebApps is
> trying to draft the final text for the Widget Requirements
> document regarding a URI scheme for widgets and we would
> again appreciate some input from the TAG. WebApps WG believes
> that we share similar (if not the same) objective to
> resolving the TAG's issue number 61 (URI Based Access to Packaged
> Items) [2].
> Regarding URI based access to packaged items, the Widgets 1.0
> Requirements document [3] contains the following Requirement:
> ------
> R6. Addressing Scheme
> A conforming specification MUST specify or recommend an
> addressing scheme to address the individual resources within
> the widget resource at runtime. The addressing scheme MUST be
> able to address individual widget instances, while
> potentially allowing widgets to address each other. The
> addressing scheme MUST NOT expose the underlying file system
> to the instantiated widget and an instantiated widget MUST
> NOT be able to address resources outside the widget resource
> via the addressing scheme. The addressing scheme SHOULD be
> one that web authors would feel comfortable using or to which
> they are already accustomed.
> Motivation:
>     Ease of use, compatibility with other standards, current
> development practice or industry best-practices, security.
> Rationale:
>     To allow resources to be resolved and normalized within
> DOM attributes. To make it easy for authors to address and
> load resources into their instantiated widgets, either
> declaratively or programmatically. For example, addressing a
> resource via an IRI (e.g.
> <img src="images/bg.png'/> where the src attribute resolves
> to something akin to "widget://myWidget/images/bg.png")).
> -------
> However, Krzysztof Maczyński has suggested we change the text
> above based on the following reasoning:
> >On 2008/7/26 Krzysztof Maczyński <> wrote:
> >> must not be able to address resources outside the widget
> resource via
> >> the addressing scheme
> > Such ability may be useful (in some future version or even
> in this one), although I can see the concerns. But it seems
> harmless, for example, to use URNs (with semantics handled by
> widget user agent, such as accessing the default instance
> (forms in older versions of VB have those) or some operating
> environment motives and artifacts - these are "outside the
> widget resource", right?). I presume there will be places
> where IRIs unconstrained by this addressing scheme can be
> used to allow such usage. Still, I think this must not cannot
> be enforced syntactically without disallowing relative IRI
> references (and I can see no reason for disallowing them).
> Another issue with this is that other instances of the same
> widget are themselves "resources outside the widget resource"
> (but not widget resources). Even though R5 currently only
> provides for addressing resources contained in the widget
> resource associated withj a given instance of the widget, I
> believe the goal is (or should be) to enable addressing the
> instances themselves as well. I would therefore suggest the
> wording given below for the entire paragraph. Also please
> clarify that "addressing scheme" means some recipe for
> minting URIs, not necessarily a URI scheme (which may or may
> not result from ongoing discussion as the best solution).
> > --
> > A conforming specification must specify an addressing
> scheme (a new URI scheme or some prescribed use of an
> existing one) which must or should be used to address at
> runtime the individual resources within the widget resource
> in association with the current or another instance of the
> widget, as well as these instances themselves. This does not
> preclude allowing use of arbitrary IRI references in some
> contexts defined by a conforming specification. When the
> addressing scheme is used, the widget user agent must be
> required not to expose any other resources to the widget
> instance. For this purpose a conforming specification may
> require that accessing resources identified by IRIs using the
> addressing scheme which leave the allowed space described
> above must fail. If addressing resources outside the allowed
> set described above is possible with the addressing scheme,
> determining that this is the case for a given IRI reference
> should be easy for the author, at least for absolute IRI
> references. The addressing scheme should be one that web
> authors would feel comfortable using or are already accustomed to.
> Any thoughts or comments from WebApps members or the TAG are welcomed.
> [1]
> [2]
> [3]
> --
> Marcos Caceres

Received on Friday, 8 August 2008 08:44:24 UTC