[TD-TF] minutes - 5 June 2020

available at:
  https://www.w3.org/2020/06/05-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

05 Jun 2020

Attendees

   Present
          Kaz_Ashimura, Ege_Korkan, Sebastian_Kaebisch,
          Tomoaki_Mizushima, Daniel_Peintner, Klaus_Hartke

   Regrets
          Michael_Lagally, Cristiano_Aguzzi

   Chair
          Sebastian

   Scribe
          dape

Contents

     * [2]Topics
         1. [3]Agenda
         2. [4]Preliminaries
         3. [5]Prev minutes
         4. [6]T2TRG meeting on Monday
         5. [7]Binding Templates
         6. [8]Issues
         7. [9]Issue 307
         8. [10]Issue 908
         9. [11]PlugFest
        10. [12]Topics for VF2F
     * [13]Summary of Action Items
     * [14]Summary of Resolutions
     __________________________________________________________

   <inserted> scribenick: dape

Agenda

   Sebastian: Agenda bashing
   ... minutes
   ... Monday Wishi meeting
   ... CoAP in RDF
   ... Issues
   ... PlugFest topics
   ... F2F meeting topics
   ... Anything more?

   <inserted> (none)

Preliminaries

   Sebastian: BTW, Cristiano has now "invited expert" status

Prev minutes

   <kaz> [15]May-15

     [15] https://www.w3.org/2020/05/15-wot-td-minutes.html

   <kaz> typos - eample, licnse, sript

   Sebastian: Minutes checking May 15 --> approved

   <sebastian> [16]May-29

     [16] https://www.w3.org/2020/05/29-wot-td-minutes.html

   Sebastian: iotschema.org updates, issue discussions (bug in
   JSONLD playground, ...), oneDM, Ege's static TD approach
   ... --> minutes May-29 approved

T2TRG meeting on Monday

   Klaus: no changes to Agenda recently

   Sebastian: Unfortunately I am on vacation next week
   ... asked M. Koster to present oneDM/TD discussion

   <sebastian>
   [17]https://github.com/w3c/wot-thing-description/issues/903

     [17] https://github.com/w3c/wot-thing-description/issues/903

   Sebastian: Klaus, do you think we can add issue to agenda item
   (1400Z)
   ... one important aspect for us is also the topic about
   hypermedia control, 1430Z

   Kaz: after hypermedia control discussion, we might want to take
   a look at RESTful design document

   Sebastian: Maybe Klaus can give a quick overview

   Klaus: in many meetings we had questions how to do design
   decisions
   ... this document tries to capture the best practices
   ... not a standard, it is not prescriptive
   ... e.g., long running actions --> use collection resource
   ... or light bulb, do I need history of dimming?
   ... we hope document is useful for others
   ... so far not that much feedback
   ... we appreciate any feedback

   Sebastian: Should try to make people aware about this document

   Klaus: Shall we add names to agenda points ?

   Sebastian: Some people take over whole discussion block
   ... should be fine I guess

   Kaz: Maybe we also check with M. Koster to make sure

   Sebastian: Not sure about topic "Handling URLs"

   Klaus: Not sure either

   Sebastian: No "real" news from our side I think

   Kaz: Related to DID? We should ask McCool

   Sebastian: I see.
   ... Will talk to McCool and Koster

Binding Templates

   Sebastian: CoAP in RDF
   ... we provided some basic terms in binding templates document
   already
   ... cov:options, cov:methodName, ...
   ... not yet in machine readable RDF representation (no ontology
   yet)

   <kaz> [18]Binding Template draft - 5.3.2 CoAP Vocabulary

     [18] https://w3c.github.io/wot-binding-templates/#coap-vocabulary

   Sebastian: We have HTTP ontology
   ... we need the same for CoAP
   ... VC started initial document for MQTT and also CoAP

   <sebastian>
   [19]https://github.com/w3c/wot-binding-templates/tree/master/on
   tology

     [19] https://github.com/w3c/wot-binding-templates/tree/master/ontology

   Sebastian: we need to work on RDF (ttl files)

   Ege: Note: Vocabulary is not the same
   ... methodName vs methodCall

   Sebastian: I am happy that Klaus is also interested in the CoAP
   work
   ... we have the framework setup. we need to work on content now

   Ege: information how to use render script is in readme of repo

   Sebastian: How do we want to organize the work?
   ... github discussions, regular meetings, .. ?

   Klaus: One initial meeting to kick off would be fine

   Sebastian: Makes sense

   Kaz: initial meeting: using one TD call or additional call?

   Sebastian: Suggest additional call
   ... mainly Klaus, Ege, Sebastian, Koster, Victor
   ... Next week im on vacation, the week after is PlugFest
   ... maybe in PlugFest week?
   ... will setup Doodle poll

   Klaus: Shall we narrow down choice ?
   ... Monday, Wed, Friday does not work for me

   Ege: Thursday works for me

   Klaus: Tuesday my preference
   ... List of Editors: premature putting me on this list

   Sebastian: not "final" yet

   Kaz: I think Tuesday works better, Thursday are plenty of calls
   already

   Sebastian: OK, will setup Doodle

Issues

   <inserted> [20]Issue 899

     [20] https://github.com/w3c/wot-thing-description/issues/899

   Sebastian: Issue 899, long running actions
   ... we have different proposals
   ... Victor proposes dynamically changing TDs -->
   [21]https://github.com/w3c/wot-thing-description/tree/master/pr
   oposals/hypermedia-control
   ... Ege proposes static TDs --> patterns in TD

     [21] https://github.com/w3c/wot-thing-description/tree/master/proposals/hypermedia-control

   <Ege> [22]PR 907

     [22] https://github.com/w3c/wot-thing-description/pull/907

   Ege: proposal is in PR
   ... similar to what Victor did... unless TD is static
   ... e.g., we have fade operation returning with brightness
   value as number
   ... important to note: output refers post response
   ... want to manage fade operation (query, update, cancel)
   ... after POST/fade new resources are created (e.g., GET
   /fade/1)
   ... href of new resources can be static
   ... e.g., GET fade/ongoing
   ... 1 fade operation at the time vs. multiple operation
   ... suggest adding additional operation types (queryaction,
   updateaction, cancelaction)
   ... one problem in non-fixed href --> it is not clear how to
   get final href
   ... in case hrefs are dynamic (e.g., {id}) we need to describe
   that
   ... meaning of input/output should not change --> refers to
   action request
   ... added query>input, update>input, update>output,
   cancel>input
   ... implementations may choose the according information (e.g.,
   no cancel input needed)
   ... open issue -> how to integrate dynamic hrefs
   ... part of header of response
   ... could also be in payload
   ... complications: information in header vs. body
   ... Scripting API concerns -> access to headers?

   Daniel: Do we need {id} in header... in body seems better for
   Scripting and other protocols than HTTP/CoAP

   Ege: Issue with existing protocols

   Klaus: depending on the case we might need multiple running
   actions (e.g., different coffee orders)
   ... queeing actions vs one action is possible (depends on use
   case)

   <inserted> scribenick: kaz

   Klaus: going back to the original question about dynamic TDs
   ... starting, monitoring, etc.
   ... pause, resume, etc.

   <inserted> scribenick: dape

   Klaus: instead of working with ids, plugging in url templates

   Ege: Makes sense

   Klaus: descriptive vs. prescriptive
   ... need to look what products do today

   Ege: we should not have to change... maybe we do not support
   alle specific solutions
   ... e.g., with what has been shown we can describe Mozilla
   implementations

   Kaz: Useful if we could have concrete use-cases/devices
   ... should clarify variations

   Ege: can look at some examples (Mozilla, coffee machine)

   Kaz: Yes, please think about concrete devices
   ... and combination of devices so that we could clarify actual
   behavior of them and what is required to handle them. that
   would be useful for this initial discussion of course, but
   would be useful to the future plugfet as well

   Ege: should also look into Oracle implementation

   <Zakim> dape, you wanted to running actions

   Daniel: starting with requirements lists also?

   <inserted> kaz: right, and if we could clarify use cases and
   scenarios with concrete device setting, it would be easier to
   clarify the requirements as well :)

   <inserted> EK: thought there were some use case descriptions
   related to hypermedia control already

   Sebastian: Let's start with looking into the Oracle and Mozilla
   use cases
   ... w.r.t. PlugFest
   ... we have 2 versions on the table. shall we pick one or check
   out both
   ... my feeling is we might want to evaluate both

   Ege: +1

   Kaz: after clarifying the use cases and requirements, we could
   clarify which would be better. or there is a possibility that
   both approaches could be handled

   Sebastian: Suggest merging PR 907

   <kaz> [PR 907 has been merged]

   Sebastian: T2T discussions on Monday will be helpful also

Issue 307

   <sebastian> [23]Issue 307

     [23] https://github.com/w3c/wot-thing-description/issues/307

   Sebastian: Next issue $ref
   ... initiated by Toru a while ago
   ... use $ref from JSON schema in TD also
   ... allows to define model in global space and point to it
   (reduces redundancy)
   ... I support introducing $ref

   Ege: there is one limitation: validate input/output by getting
   schema
   ... input for example is not any longer self-contained

   <kaz> [24]Example 1

     [24] https://www.w3.org/TR/wot-thing-description/#simple-thing-description-sample

   Sebastian: whole TD is JSON schema valid

   Ege: Correct, but validation would like to check value only

   Daniel: Dynamically updating json schema constructs

   Ege: Correct, or passing multiple schemas to validators

   <Ege>
   [25]https://github.com/tum-esi/wot-sys/blob/master/Devices/node
   wot-pantilthat/src/base.ts#L315

     [25] https://github.com/tum-esi/wot-sys/blob/master/Devices/nodewot-pantilthat/src/base.ts#L315

   Ege: "outer" definitions are not visible to validators

   Sebastian: Correct. We need to combine the outer definitions
   with the interaction type definitions
   ... Shall we work on proposal

   Klaus: $ref at JSON level or TD level
   ... recommand TD level

   Daniel: Support having one global space for definitions

   Sebastian: Question: allowing referring to "external" files

   Klaus: Useful, but what happens IF TD is retrieved from
   somewhere et cetera.. or should it selfContained

   <Ege> I need to leave now :)

   <Ege> See you next week

   Klaus: compromise: TD templates
   ... TD might be better selfContained
   ... oneSDF / WISHI has same discussion

   Kaz: old issue, so maybe kind of related to Kajimoto-san's
   object-oriented project. however, I think this is definitely
   related to the TD Template discussion.
   ... so we should think about use cases and requirements for
   both this proposal and the TD Template proposal a bit more, and
   then get back to this proposal itself later.
   ... relates to TD template as well

   Sebastian: Not sure if it fully tackles Kajimoto-Sans
   proposal/idea

   Kaz: yeah, this proposal #307 might be not directly taking over
   Kajimoto-san's idea, but we should work on requirements first

   Sebastian: Will work on proposal and requirements

   Daniel: I am interested also

Issue 908

   <sebastian> [26]Issue 908

     [26] https://github.com/w3c/wot-thing-description/issues/908

   Sebastian: Next issue, 908, no default value for observable

   Klaus: what does "observable" mean? not intersting to observe
   or possible to observe

   Sebastian: observable does not say anything about stability of
   value

   Daniel: not much value in observable

   Klaus: +1

PlugFest

   Sebastian: talked about a bit
   ... test new terms, long running actions
   ... maybe CoAP RDF is ready

Topics for VF2F

   Sebastian: Any input?
   ... feeback from PF about long running actions
   ... TD templates
   ... $ref/definitions from JSON schema
   ... oneDM TDT
   ... iotschema
   ... please contact me via email if you have more topics

   Kaz: CoAP RDF ontology

   Sebastian: Yes
   ... Next week I am on vacation. I will ask Taki to moderate

   <kaz> [adjourned]

Summary of Action Items

Summary of Resolutions

   [End of minutes]
     __________________________________________________________


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Received on Monday, 15 June 2020 11:51:08 UTC