[Standards] Best approach for Shared XML editing

Bishop, Michael W. CONTR J9C880 Michael.Bishop at je.jfcom.mil
Tue Sep 16 15:03:57 CDT 2008


We are in the process of updating the XEP.  We realize our section on
history wasn't as clear as it needs to be.  Our implementation of
history has outgrown the spec and we're updating the spec to reflect how
it's done.  Once we reconcile these issues, we can provide an updated
XEP.

In short, for one-to-one, each WB session is treated as a new session.
You can share a previously shared whiteboard by loading it from the file
system.  Our client will break the loaded whiteboard into events and
send them to the remote user one by one.

For MUC, it's done with session IDs and sequence number.  A user can
enter a MUC and request an entire whiteboard or everything that's
happened since sequence number X.  We'll have a complete explanation and
examples in the XEP revision.

It should be noted that our spec uses SVG for examples because it's our
main focus.  Nothing in the protocol limits it to SVG.  I believe it
could be used to maintain any form of XML document.

We've run into no scaling issues with our implementation.  As for the
server plugin, we're currently allowed to distribute the OpenFire
plugin's binary.  We're still working on getting cleared to release the
source.

I'm not sure what you mean by the protocol implemented by the
server-side plugin.  It adheres to the same whiteboarding protocol.

Michael Bishop

> -----Original Message-----
> From: standards-bounces at xmpp.org [mailto:standards-bounces at xmpp.org]
On
> Behalf Of Yann Biancheri
> Sent: Friday, September 12, 2008 5:21 AM
> To: XMPP Extension Discussion List
> Subject: Re: [Standards] Best approach for Shared XML editing
> 
> Thanks for all these answerers! I didn't expect so much!
> Would it be possible to share with us a newer  version of the
> whiteboard XEP. It's currently unclear how a client can join an
> ongoing whiteboard session and  how he would synchronize his state
> with the current whiteboard. There is a small section on history but
> it lacks stanza examples.
> We are definitively targeting a server-side implementation of the
> whiteboard to helped with synchronization between participants, check
> that edit after edit, the document stays valid (in the xml sense), and
> right management. We also believe that whiteboarding would be used in
> a presentation mode where only a few occupants would be able to edit
> whereas 50 people might watch the document.
> The whiteboard protocol is definitively less verbose than SXE and by
> such should scale way better with an appropriate conflict resolution
> approach. I'm particularly thinking at the initial state
> synchronization in SXE which can be pretty verbose.
> 
> We think that having a generic protocol for xml editing is nice, but
> our only use case right now is whiteboarding so we wouldn't mind
> having a whiteboard specific protocol.
> 
> Is it possible to have access at the whiteboard openfire plugin
> sources, or a documentation on what protocol exactly it implements.
> 
> -Yann
> 
> On 11 sept. 08, at 19:21, Lirette, Keith J. CONTR J9C618 wrote:
> 
> > Our client can be downloaded from
https://xmpp.je.jfcom.mil/1.4Final/
> >
> > The TransVerse client by itself provides 1-to-1 whiteboarding.  We
> > also
> > have an OpenFire plugin that supports MUC whiteboarding.
> >
> > -Keith Lirette
> >
> > -----Original Message-----
> > From: standards-bounces at xmpp.org [mailto:standards-bounces at xmpp.org]
> > On
> > Behalf Of Bishop, Michael W. CONTR J9C880
> > Sent: Thursday, September 11, 2008 1:13 PM
> > To: XMPP Extension Discussion List
> > Subject: Re: [Standards] Best approach for Shared XML editing
> >
> > Hello,
> >
> > We've done it with our proposed specification:
> > http://www.xmpp.org/extensions/inbox/whiteboard2.html
> >
> > The date is incorrect; I don't think I changed it from the template
I
> > used.  This protocol started development in 2006.  While the
document
> > centers around SVG, it can be used with any kind of XML document.
> > We've
> > been actively working against this protocol and have future versions
> > and
> > protocol additions planned.  Currently, we've had success in test
> > plans,
> > performance testing, and live deployments in numerous environments.
> >
> > Michael Bishop
> >
> >> -----Original Message-----
> >> From: standards-bounces at xmpp.org
> >> [mailto:standards-bounces at xmpp.org] On Behalf Of Yann Biancheri
> >> Sent: Thursday, September 11, 2008 11:44 AM
> >> To: XMPP Extension Discussion List
> >> Cc: joonas at uwc.net
> >> Subject: [Standards] Best approach for Shared XML editing
> >>
> >> Hi everybody,
> >>
> >> We are looking at ways to implement whiteboarding over XMPP and
we've
> >> found lots of interesting proposals in the community already. We
are
> >> particularly interested in the sxe [1] and sxde [2] ones. It seems
> >> that sxde has been written first and has leads to sxe. What we like
> >> with sxde is that it is less verbose than sxe since you can
directly
> >> add an xml element qualified with it's namespaces, attributes,
> >> contents whereas in sxe you would have to issue one command to
create
> >> the element, and one for each of the attributes which in the end
> >> result in a lot of xml to send in the XMPP band. On the other hand,
> >> sxe is more recent, seems cleaner and more generic.
> >> We were wondering if there were any other reasons such as protocol
> >> flaws behind the move from sxde to sxe?  Or if we could use one or
> >> the
> >
> >> other eitherway?
> >> Thanks a lot for the feedback
> >>
> >> - Yann
> >>
> >> [1] http://www.xmpp.org/extensions/inbox/sxe.html
> >> [2] http://www.xmpp.org/extensions/inbox/sxde.html
> >>



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