[TD-TF] minutes - 3 April 2020

available at:
  https://www.w3.org/2020/04/03-wot-td-minutes.html

also as text below.

Thanks a lot for taking the minutes, Daniel!

Kazuyuki

---
   [1]W3C

      [1] http://www.w3.org/

                               - DRAFT -

                             WoT-WG - TD-TF

03 Apr 2020

   [2]Agenda

      [2] https://www.w3.org/WoT/IG/wiki/WG_WoT_Thing_Description_WebConf#Apr_3.2C_2020

Attendees

   Present
          Kaz_Ashimura, Daniel_Peintner, Sebastian_Kaebisch,
          Taki_Kamiya, Michael_Koster, Tomoaki_Mizushima,
          Zoltan_Kis, Klaus_Hartke

   Regrets

   Chair
          Sebastian

   Scribe
          dape

Contents

     * [3]Topics
         1. [4]Past minutes
         2. [5]REC transition
         3. [6]Issues
         4. [7]Binding Template, Ontology for CoAP
         5. [8]OAuth2
         6. [9]Binding templates
         7. [10]Bank holiday next Friday? Good Friday
     * [11]Summary of Action Items
     * [12]Summary of Resolutions
     __________________________________________________________

   <kaz> scribenick: dape

Past minutes

   <kaz> [13]Mar-27 minutes

     [13] https://www.w3.org/2020/03/27-wot-td-minutes.html

   Sebastian: review of minutes and virtual F2F minutes
   ... rec status
   ... issue w.r.t. eventing... templates/common patterns
   ... talk about efficient formats
   ... objections?
   ... no -> approved

REC transition

   <inserted> [14]draft for REC

     [14] https://w3c.github.io/wot-thing-description/publication/rec/

   Sebastian: Approval for TD, publish April 9

   Kaz: got response from Jeff about quote... waiting for response
   of Coralie

   Sebastian: Perfect
   ... waiting for some testimonals... having testimonals later is
   also fine

   Kaz: will check the TD document again.. changing the dates et
   cetera during weekend
   ... are we OK with CSS settings about highlighting

   Sebastian: Yes, look better now
   ... still some minor issues when it is not valid JSON. Anyhow,
   it is ok

   Kaz: fixed JS and it works

   <Zakim> dape, you wanted to with default dynamic

   Sebastian: TD draft looks good!

Issues

   Sebastian: Event patterns,
   [15]https://github.com/w3c/wot-thing-description/issues/887
   ... coming from scripting
   ... common patterns for eventing, eg., subscription ID
   ... cancelling requires subscription ID again
   ... Question: can we generalize such approaches
   ... M. Lagally provided a more complex eventing mechanism
   ... checked standards such as WebSub
   ... no ID handling used as it seems
   ... Yes, likely they keep open socket

     [15] https://github.com/w3c/wot-thing-description/issues/887

   Daniel: I believe SSE does not need it either.. keep open
   connection

   Koster: Yes, SSE keeps open HTTP connection with keep alive
   ... metadata in the stream
   ... syntactical convention
   ... could build subprotocol for it
   ... SSE, WebSub need a sub protocol
   ... MQTT as well

   Sebastian: For MQTT we would not need handler, based on topic
   ... "data" container might be sufficient
   ... no subscription/cancellation
   ... in binding templates we propose the retain flag.. means
   possible to write property
   ... for eventing, don't use retain flag simply define event
   ... kind of guideline
   ... What about observe CoAP

   Koster: CoAP has separate address
   ... couple of options
   ... read with observe flag
   ... believe we have related issues in binding

   Zoltan: first sample of event coming right away
   ... read with event flag

   Koster: Unsure what the first value means.. no event took place
   ... ignore first value

   Sebastian: Question is what is handled by the protocol
   ... e.g., CoAP observe. Binding knows what to do by skipping
   first value
   ... this information should not be in TD

   Koster: Believe we have related issue

   Sebastian:
   [16]https://github.com/w3c/wot-thing-description/issues/878?

     [16] https://github.com/w3c/wot-thing-description/issues/878

   Koster: Initial connection should not be described in TD?

   Sebastian: MQTT needs connection to broker before doing
   anything
   ... no information in TD how the setup works? Relates to
   specific binding
   ... href may contain broker address and topic

   Koster: "unsubscribe" should be added in example 34 (binding)
   or remove op at all
   ... first time encountering href you could connect...
   ... cache connection
   ... security information are still required

   Sebastian: Yes, in securityDefinitions ...e.g. basic
   ... TD gives you the information about security etc. MQTT
   binding takes this information and setups the actual connection

   Koster: Security definition needs broker address also
   ... could be 3 different brokers

   Zoltan: MQTT and OCF could use event interaction and hide the
   internals

   Sebastian: securityDefinitions might contain multiple security
   information

   Koster: Forgot that security can be present locally in form
   also

   Sebastian: Tradeoff between how much information in TD and how
   much information in binding

   Koster: A bit complex but works (caching connections with
   various security schemes et cetera)

   Sebastian: Ben mentioned Mozilla uses own websocket protocol
   ... essentially don't need form anymore

   Koster: Why don't we do that for MQTT as well?

   Sebastian: We could
   ... topic is still needed

   Ege: initial connection is implicit in HTTP if you keep sockets
   alive

   Koster: Yes, but there is a header for that

   Sebastian: Coming back to original question. We still need a
   good overview about existing eventing patterns
   ... looking at Oracle cloud
   ... CoAP observe
   ... MQTT
   ... Issue,
   [17]https://github.com/w3c/wot-thing-description/issues/888

     [17] https://github.com/w3c/wot-thing-description/issues/888

   Ege: Background: property is readable and writable
   ... read is not value you wrote.. some wrote in between
   ... in case of oberserve, should I get the value I wrote

   Koster: notifications lost?

   Zoltan: transaction support

   Koster: 1. should there be a notification... I think yes

   Ege: Any write request should generate notification

   Koster: CoAP creates notification for every update
   ... there will be open questions w.r.t. protocol

   Ege: I just believe we should have some information in behavior
   assertions

   Koster: "Looser" approach works better.. not making too strict
   assumptions

   Sebastian: I am wondering about the relevance?

   Ege: testing and behavior. Section 8 of TD also

Binding Template, Ontology for CoAP

   Sebastian:
   [18]https://github.com/w3c/wot-binding-templates/issues/93
   ... similar to HTTP start work on CoAP

     [18] https://github.com/w3c/wot-binding-templates/issues/93

   <mjk> [19]https://www.w3.org/TR/HTTP-in-RDF10/

     [19] https://www.w3.org/TR/HTTP-in-RDF10/

   Sebastian: Kaz, can we create a own github repo for ontology on
   CoAP?
   ... also who is willing to support this task (so far Klaus and
   Sebastian)

   Ege: Willing to support

   Koster: would like to be involved in MQTT also

   Ege: Need also someone from MQTT area

   Sebastian: at building IOT conference I meet some MQTT people.
   will try to reach out

   Koster: could also reach out to Eclipse founation guys

   Kaz: w.r.t. ontology repo: I am wondering about usage and
   content

   <kaz> [20]ontology file

     [20] https://w3c.github.io/wot-thing-description/ontology/td.html

   Kaz: move the html file to new repo?

   Sebastian: Vocabulary could be used by TD but should not be
   limited to TD

   Kaz: HTTP RDF work kind of abandoned
   ... do we want to create such work/notes

   Sebastian: Would keep work in TD call... having status reports
   ... charter says 2.12 "protocol vocabulary and bindings"

   Kaz: Note: new process within W3C, evergreen process
   ... let's discuss it in main call

   Sebastian: OK, let's do so...

   Koster: Could start in binding template document

   Kaz: btw, to be strict, "ontology" is different from
   "vocabulary"

   Koster: For our purpose it is equivalent

OAuth2

   <sebastian>
   [21]https://www.w3.org/WoT/IG/wiki/File:2020_TD_Topics_vf2f.pdf

     [21] https://www.w3.org/WoT/IG/wiki/File:2020_TD_Topics_vf2f.pdf

   Sebastian: slide #18
   ... have OAuth2 support in TD but had to remove at-risk
   features
   ... "flow" term
   ... based on GovTech Singapore discussion these missing terms
   are needed
   ... idea is to bring it back to the status we had before
   removing the at-risk features
   ... node-wot will be offering OAuth2 support also very soon.
   Work has been started.
   ... after TD document being published we should bring back this
   work

Binding templates

   Ege: [22]https://github.com/w3c/wot-binding-templates/issues/94
   ... little problems pointed out
   ... issue with XML double/number

     [22] https://github.com/w3c/wot-binding-templates/issues/94

   Daniel: comes from EXI4JSON, can look this up

   Taki: will take a look

   Ege: [23]https://github.com/w3c/wot-binding-templates/issues/21
   ... fixed some attribute names

     [23] https://github.com/w3c/wot-binding-templates/issues/21

   <Ege>
   [24]https://pr-preview.s3.amazonaws.com/w3c/wot-binding-templat
   es/pull/95.html

     [24] https://pr-preview.s3.amazonaws.com/w3c/wot-binding-templates/pull/95.html

   <Ege> [25]https://github.com/w3c/wot-binding-templates/pull/95

     [25] https://github.com/w3c/wot-binding-templates/pull/95

   Ege: ML pointed to term "value scaling"
   ... not sure about this whole section
   ... removed 4.4
   ... also specified OCF version 1.3
   ... added references (e.g., SenML)

   Koster: Could also point to latest OCF version

   <Ege>
   [26]https://github.com/w3c/wot-binding-templates/issues/94

     [26] https://github.com/w3c/wot-binding-templates/issues/94

Bank holiday next Friday? Good Friday

   Sebastian: Holiday in Europe...
   ... suggest cancelling the call
   ... next meeting in 2 weeks

   <kaz> [adjourned]

Summary of Action Items

Summary of Resolutions

   [End of minutes]
     __________________________________________________________


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Received on Saturday, 18 April 2020 07:47:41 UTC