Summary of Boston Face to Face 8-10 November 2007

The face to face meeting of the Ubiquitous Web Applications working
group took place at the Hyatt Regency in Cambridge Massachusetts, as
part of the combined Technical Plenary and Advisory Committee
Meetings.

Thursday 8 November 2007:

DISelect/XAF:

Rhys has prepared a test suite for DISelect/XAF as well as a couple
of implementations, one of which is implemented in JavaScript.
Stephane tracking down Max's implementation. Dave will check with
JustSystems about the possibility of an XSLT+JavaScript based
implementation, based on allowing XSLT to access the delivery
context via XAF. We hope to move DISelect/XAF to PR by early next
year.


UWA Wiki/Blog:

Dave is planning on reorganizing the entry page for the wiki and
asks for suggestions on what is needed. We would like to explore
using the Wiki for preparing W3C Notes and Working Drafts, and Dave
will ask Sandro Hawke for advice on techiniques for achieving that.
Rhys has a tool for offline editing of the wiki in Eclipse.

The UWA home page is based on a blog (b2evolution) and Dave is
hoping to improve the UI to enable browsing blog entries by tag. The
current tags are News and Minutes. Dave also wants to exploit the
blog to promote the UWA vision and roadmap, and invites working
group members to help with this.

Dave will update the wiki/roadmap with instructions for how to
maintain a stable URI for the latest version of editors drafts.


Coordination with other groups:

We held a joint session with the Device Description working group,
and with a representative of the OMA DCAP group (Bennett Marks). We
mostly discussed the Delivery Context Ontology and coordination
across groups. The ontology is being maintained using "Protege", and
currently focuses on mobile devices, but we intend to broaden this
to printers and cameras etc.

Rhys has a nice diagram showing the relationship between DCCI, DPE
and the DD APIs. He will add this to the Wiki as part of an FAQ for
the delivery context, and drawing on the questions raised by a
number of people at the face to face.

DCCI is a client side interface to the delivery context, while DPE
and DD are server-side interfaces. DD is limited to static
properties for models of devices rather than specific devices. DPE
provides dynamic access to the delivery context in a specific
device using a bandwidth/latency optimizing protocol.

The ontology describes the data model at a level above that of
individual APIs and forms the basis for obtaining broad concensus
across different groups. Recent work on screen orientation involved
coordination across W3C, OMA and 3GPP.

We envision a regular cycle of updates to the ontology, using the
last call process to address coordination with other groups. The
first public working draft is expected by the end of 2007.

We hope to cover richer access to device capabilities in the
ontology, e.g. device location, address book and calendar, drawing
upon existing work (e.g. vCard, vCal and iCalendar).

Friday 9 September 2007:

Location:

We started with a discussion on exposing device location to web
applications. Location involves privacy issues and we need to
collect information on how location is being used in different parts
of the world along with the associated regulatory environment. In
countries like Japan, there are strict legal constraints on location
based services.

Wider use of location and other privacy-related services is
dependent on addressing the associated security and trust issues.
W3C plans to hold a workshop on access control and trust models in
2Q'08 (probably June) to address these issues. This may lead to a
new working group in the W3C Security Activity. Some further
background is given at:

     http://www.w3.org/2007/uwa/wiki/Trust_models

Another issue that came up in discussion is the nature of the
business models for location based services and how this changes
when location is exposed directly to web applications as opposed to
locally installed applications, e.g. are subscription-based models
viable if you can create location-based mashups with free mapping
data? The answer would seem to depend on the value added through
combining such maps with other data.

We reviewed JSR179 (J2ME interface for location) and Bennett
suggested also looking at GPX, an XML based format for exchanging
location data. It looks like it will be quite straightforward to add
a numerical treatment of location to the delivery context ontology,
see

     http://www.w3.org/2007/uwa/wiki/Leveraging_JSR179

However, textual or semantic representations look like being harder
to reach a global concensus on, and perhaps best left to web
applications to deal with, e.g. via Ajax.

DCCI:

A CR transition meeting is tentatively scheduled for mid-December.
Keith Rosenblatt accepted an action to package up and submit the
test assertions and test suite developed by France Telecom. We were
joined by representatives of the MMI working group to go over their
last call comments. These were all resolved satisfactorily and we
are on track for the transition meeting.

Declarative Authoring:

With key working group members having to attend other meetings, this
was more of an informal educational session than a formal working
group meeting. The basic idea is that HTML is increasingly too hard
to author especially given the need to deal with security,
accessibility, ease of maintenance and adaption to different
delivery contexts, see:

http://www.w3.org/2007/uwa/wiki/Declarative_modelling_of_rich_web_apps

A layered architecture is proposed and it now looks like it would be
timely to launch an Incubator Group to study use cases, requirements
and potential solutions for end-to-end authoring. This would then
feed into rechartering the UWA working group, whose charter expires
in March 2009.

Some areas to be addressed include the means to specify behavior,
e.g. with declarative event handlers expressed in XML. The WAI-ARIA
ontology of UI controls looks like a promising basis for defining
markup for the concrete UI layer. XBL might provide a basis for
packaging components that can be realized as HTML/Ajax libraries.
The UWA working group is already chartered to work on policy based
layout and remote user interfaces, and it looks like we will be
collaborating closely with the XSL working group on many of these
items.

Saturday 10 November 2007:

Saturday morning was devoted to device coordination and the means to
support distributed web applications involving many different kinds
of devices (the Web of Things). See

      http://www.w3.org/2007/uwa/wiki/Device_Coordination

Kangchan Lee gave a presentation on the terminology and use cases
for device coordination. He accepted an action to add these to the
wiki along with an associated FAQ. We will also consider updating
the glossary inherited from the former Device Independence working
group.

Kazuhiro Kitagawa presented the work of the PUCC (Peer to Peer
Universal Computing Consortium). This is essentially metadata and
overlay protocols for accessing a range of consumer electronics
devices like printers, and is being implemented by a number of
Japanese manufacturers. The plan is to submit the metadata to W3C
with a view to publishing it as W3C working drafts in early 2008. We
also expect to leverage this for extending the delivery context
ontology to cover such devices.

One of the challenges is to ensure that the metadata is rich enough
to allow the generation of the corresponding JavaScript interfaces,
including the events that the associated objects raise or respond
to. Another issue is how to deal with messaging across security
boundaries like NATs, e.g. to allow events to be delivered from
remote resources.

The UWA working group is chartered to work on resource binding
interfaces and it may be appropriate to also work on bindings to
specific event handling protocols such as HTTP, SIP and XMPP.
Further work is needed to understand how this relates to the needs
for remote user interfaces and for declarative event handlers.

The next face to face is planned for the first week in March 2008,
in Seoul, South Korea, hosted by ETRI, and co-located with meetings
for the MWI Best Practices and Device Descriptions working groups.

Agenda:
    http://www.w3.org/2007/uwa/wiki/November_2007_F2F

Thursday PM:
    http://www.w3.org/2007/11/08-uwawg-minutes.html
    http://www.w3.org/2007/11/08-ddwg-minutes.html#item04

Friday AM:
    http://www.w3.org/2007/11/09-uwawg-minutes.html

Friday PM:
    I am missing the notes taken from the afternoon session on
    declarative authoring, if you took some, please let me know.

Saturday AM:
    http://www.w3.org/2007/11/10-uwawg-minutes.html

I am hoping to publish all the presentations and to link them from
the wiki.

  Dave Raggett <dsr@w3.org> http://www.w3.org/People/Raggett

Received on Friday, 30 November 2007 16:03:13 UTC