W3C

– DRAFT –
WoT Profile

15 June 2022

Attendees

Present
Ege_Korkan, Kaz_Ashimura, Michael_Lagally, Michael_McCool, Tomoaki_Mizushima
Regrets
-
Chair
Lagally
Scribe
kaz, McCool

Meeting minutes

Minutes

<kaz> May-25

<mlagally> https://github.com/w3c/wot-profile/issues/179

reviewing minutes, notes about JSON Schema, using version 7

Lagally: point is there is another spec for validation that includes particular formats like date-time

Lagally: there is an issue, see minutes
… issue #209 in wot-profile

Lagally: approve?

Lagally: no objections, approved

Cleaning up

PR #203

<kaz> PR 203 - Cleanup core with baseline / information model

Lagally: replace "core" with "baseline"
… some comments from bf about other changes needed, ml wanted to limit scope

McCool: are "baseline profile" and "HTTP baseline profile" different>

Lagally: yes, a little inconsistent

Ege: not a small issue, Baseline = core, but HTTP Baseline is more specific

Lagally: this PR is a cleanup pass, not a reorg

McCool: still, would it be possible to fix all ocurrences of "Baseline" to "HTTP Baseline"?

Lagally: propose we do that in another iteration

McCool: ok, but need an issue

Kaz: I'm OK with that but we should fix the spec asap

McCool: bottom line is we agreed to use "HTTP Baseline Profile" only, so any use of "Baseline Profile" is a mistake and needs to be fixed

Lagally: creates issue #210

<kaz> Issue 210 - Consistent use HTTP baseline profile

Ege: image also needs to be updated

Lagally: as image has other problems, will create another issue for that

Lagally: creates issue #211

<kaz> Issue 211 - Image update for HTTP baseline profile

Lagally: assigning both to ege

McCool: how exactly should figure be updated?

Ege: is it generic, or for a specific profile?

McCool: I think this depends on the context of the text; the current text is specific but if we edit it to be more generic, figure will change in different ways

Lagally: also a large section marked as at-risk; the data model

McCool: this was the section that bf was concerned about?

Lagally: yes; so is in there, but marked as being at-risk, with reference to the issue where it is being discussed

McCool: anyway, ok with merging this PR for now, even if imperfect

Issue #200: Length and size limits

Issue 200 - Revisit length limits

Lagally: length limits and constraints

Lagally: agree these values are arbitrary...
… let's talk about whether we want constraints or not

McCool: couple of thoughts; interconversion to/from; constrained devices; TM constraints

Lagally: example, ids that exceed length limits, first 512 are identical
… that would break use cases
… so these constraints are a contract, compliant things must not provide longer values

McCool: and even high-end systems, e.g. relational databases, may have finite limits

McCool: think we should lay out use cases; I see three, interconversion, constrained devices, and other systems with limits (databases)
… interconversion though is very difficult, may be many format in conflict with each other

Ege: agree that interconversion raises a very complicated set of issues
… think we should drive with basis on constrained devices and databases

Ege: btw prog langs don't make sense a driver of limits, tend to be very high
… need to look at other constraints, e.g. relational databases
… also watch out for "bytes" vs "characters"

McCool: should use UTF-8 and bytes

Ege: need to relate to JSON string lengths

Kaz: can think about this by ourselves, but might want to talk to other SDOs, i.e. IETF, OneM2M, etc.

Lagally: did give a couple of spec references

McCool: not only what limits are, but how they are defined, e.g. bytes vs chars

Kaz: also IEC dictionary people

McCool: right, UTF-8 "character" can expand to up to 4 bytes in memory...

Lagally: agree that bytes are better, less confusing

McCool: and also gives a tighter limit

Ege: JSON validation is troublesome, may need a special validator

Lagally: ok, let's go with bytes, let's start with a strawman

<kaz> [adjourned]

Minutes manually created (not a transcript), formatted by scribe.perl version 185 (Thu Dec 2 18:51:55 2021 UTC).