W3C

WoT Discovery

03 May 2021

Attendees

Present
Cristiano_Aguzzi, Daniel_Peintner, Farshid_Tavakolizadeh, Kaz_Ashimura, Michael_McCool, Tomoaki_Mizushima
Regrets
Andrea, Christian
Chair
McCool
Scribe
dape, kaz

Meeting minutes

Minutes approval

<kaz> Apr-26

McCool: Any objections?

-> none -> approved

Scripting

<zkis> https://github.com/w3c/wot-scripting-api/issues/314

Zoltan: We simplified *older* stuff
… can use direct or directory

McCool: *nothing* gives you back what you have?

Zoltan: Is URL needed always?

McCool: we start from *nothing*
… output is set of TDs

Zoltan: 2 aspects
… developer faces API
… delivery mechanism (iterator at the moment)
… no pagination

McCool: implementation can support it internally?

Zoltan: yes

McCool: pagination is more for network

Zoltan: stanzas?

McCool: problematic with Canonicalization which does re-ordering

Farshid: w.r.t. ordering
… query what is needed first

Zoltan: query supported as filters
… search meant for filters

McCool: implementations can do internal filters/searches.. returning full TDs

McCool: TDs are usually relatively small

McCool: What about languages? JSON-Path or SPARQL returning parts

Cristiano: Support just filters TDs but not support selects

Daniel: "selects" for use-cases that purely want to do discovery.. not useful for Consumed/ExposedThing

Zoltan: Might use sub-set of queries

Cristiano: not sure about case whether URL is always needed

McCool: script says "please discover" ..and comes back with results
… open issue... authorize access to TDs

Cristiano: security parameter needed?

McCool: existing security mechanisms for TDs .. to fetch
… management API?

Cristiano: not clear: direct/directory is for 2nd phase only
… believe we should stick with 2nd phase for now

McCool: easier for now to use url
… in general ... url should not be necessary

Zoltan: Yes, need further discussion w.t.r. in Scripting
… discussed management API ... with various sub-API

McCool: technically ... fetching TD might return directory.. should handle gracefully
… directories are also "things" ...
… maybe it can be figured out automatically what it is

Cristiano: direct returns TD .. even for directory
… directory pointing to simple TD should fail with error

Zoltan: let's have internal discussion in scripting next.

PRs

Rename DirectoryDescription to ThingDirectory

PR 161

Farshid: changes @type only

McCool: Looks good to merge

Rename actions to match properties and events

PR 160

Farshid: Ben asks for using type

McCool: I am ok with type addition but should not be a MUST

Cristiano: Ben has the opinion that name is not normative

McCool: "name"s is normative ... anyhow adding @type is okay
… I am OK with terminology change

Farshid: PATCH is gone

McCool: I disagree with that change...
… suggest not to merge it now.
… concerns with merging PATCH with PUT
… formIndex not easy to specify in scripting

Cristiano: general problem

Daniel: formIndex is there but much easier to go with interaction name

CA/MMC: Yes, much easier

Farshid: contentType are different for those 2 methods

McCool: original API seemed simpler

Cristiano: Maybe work together with TD task force ... w.r.t. selecting methods
… e.g., using uriVariables

McCool: Bens proposal seems to be more RESTful but also puts focus on HTTP

<kaz> McCool adds comments

Kaz: agree we should clarify our intentions/requirements

McCool: example/TD should be a ThingModel and normative

Farshid: It is an example now but we plan to change it

Kaz: expected features should be listed normatively in the document in addition to the example code.

McCool: all directories SHOULD be implementing it

<kaz> McCool adds another comment

Farshid: There is another class we could use ... used in TD for JSON Schema

Combine properties into a single things property

PR 158

Farshid: has same problem.. merging also into one... like PR #160

Split registration event into multiple events

PR 159

Farshid: Not sure about the benefits
… 3 differents events
… I don't mind separating but i don't see the benefit

McCool: query approach seems more extensible

Cristiano: new api has several events ?

Farshid: Yes, 3

McCool: please follow-up on issue

Typos

PR 166

McCool: explicit .. wrong

Daniel: will do a new PR against wd-update-candidate

<kaz> McCool adds comments as a help for Daniel

Expiry date for registered TDs

PR 162

Farshid: changes in registration
… new fields: expired, ttl, retrieved
… retrieved optional?
… work is not finished yet

McCool: looks reasonable
… discuss it again next time

AOB

McCool: FYI, Security TF working on TD signing

[adjourned]

Minutes manually created (not a transcript), formatted by scribe.perl version 131 (Sat Apr 24 15:23:43 2021 UTC).