W3C

– DRAFT –
WoT-WG - TD-TF - Slot 1

15 January 2025

Attendees

Present
Cristiano_Aguzzi, Daniel_Peintner, Ege_Korkan, Kaz_Ashimura, Kunihiko_Toumura, Michael_Koster, Tomoaki_Mizushima
Regrets
Mahda
Chair
Ege, Koster
Scribe
cris

Meeting minutes

Minutes review

<kaz> Jan-8

Ege: last week we discussed binding templates and uri schemes
… any problems ?

Ege: minutes approved

TD

QueryAction operation

<kaz> Issue 2068 - Specify the result of queryaction operation

Ege: this is a big discussion (at lest this is what we agreed last time)
… to really solve it now (creating a feature for TD 2.0) would take to much time
… how do we want proceed?
… my proposal is to have a dirty solution for TD 1.1
… and then have a real solution later on as part of manageable affordances

Daniel: from my point of view, we need to fix in TD and then see if it works in Scripting

Ege: really fixing in TD 1.1 we would need actually to create an errata

Daniel: I don't like to have an hacky solution
… we don't want to have an errata

Cristiano: I think we can work with it leaving underspecified but without taking assumptions (do workarounds)

Kaz: I agree, if we want to update TD 1.1 specification that would be a normative change and it should be applied to 2.0 (as a new version).

Daniel: What we shouldn't do is creating a method call that needs to be reviewed in the next iteration
… this is more a Scripting API discussion

Kaz: There are two questions here, one about TD and another about Scripting API, so we should clarify two resolutions for them separately.

<EgeKorkan> proposal: The issue 2068 will not be addressed in TD 1.1

RESOLUTION: The issue 2068 will not be addressed in TD 1.1

<EgeKorkan> proposal: In TD 2.0, the issue 2068 will be fixed

RESOLUTION: In TD 2.0, the issue 2068 will be fixed

URI Scheme

<EgeKorkan> node-wot PR 1335 - opcua: nsu in nodeId (fixing #1334)

<EgeKorkan> wot-thing-description Issue 2069 - URL Scheme Decision

Ege: we should use the issue above
… to discuss further
… basically since in OPC UA there could be reserved characters in the nodeId
… the idea is to encode it only when it is needed
… fore example if a node id is http://.... the // won't be escaped
… this is the decision taken for opc-ua
… but there might be implications also for other protocol bindings

Koster: we also discussed to use the path
… with mqtt we are using other parameters
… but I'm not sure if it was impacted

Cristiano: we went back and forth but we decided to use the query parameter which need less escapes

Daniel: what the decoder should do?
… it just need to solve the `#` and `&`, right?
… probably you should encode also `%`

Cristiano: yeah

Daniel: then it means that in the encoding side we are doing something special and in the decoding side not

Cristiano: right that's why it would be better just to note that the nodeId goes in an URI so any special character should be encoded

Daniel: I like this point, ZIP does something similar too. They just define the decoder rules.

Ege: I would just direct people to not encode everything
… because we get better readability

<kaz> Percent-encoding

Kaz: when we say encoding and decoding, does that mean Percent-encoding ?

Ege: URL encoding?

Kaz: yes, they are the same concept

Kaz: We should ask TAG for advice
… when do we want to do that?

Ege: since the discussion is almost settled down I would use issue 2069, summarize the decision, and ask for help

<EgeKorkan> wot-thing-description Issue 2069 - URL Scheme Decision

<kaz> wot-binding-templates Issue 292 - MQTT URI Design

<EgeKorkan> w3c/wot-binding-templates#292

Ege: in mqtt there is the same issue
… there we have `#` and `*`
… the decision so far was similar to what is now decided in opc-ua

Ege: probably it was more delicate in mqtt

Cristiano: yes, probably because we were trying to fit the topic in the path element of an uri

Ege: . and .. are problematic in MQTT
… I hope they are not used that much

Cristiano: When `..` and `.` are problematic?

Ege: it seems everywhere

Daniel: we can still use the query parameter
… without having to worry that much about / and URI arithmetic
… and maybe more consistent

Cristiano: having the topic in the path would allow to do some simplification when writing the URL

Ege: ok thank you, tomorrow we will discuss registry inclusiveness

Ege: please be there we want to reach a resolution

[adjourned]

Summary of resolutions

  1. The issue 2068 will not be addressed in TD 1.1
  2. In TD 2.0, the issue 2068 will be fixed
Minutes manually created (not a transcript), formatted by scribe.perl version 242 (Fri Dec 20 18:32:17 2024 UTC).