[Scripting] Discovery of exposed Things on the same runtime

[h0ru5]

referring to
https://github.com/w3c/wot/blob/master/meeting-results/beijing-f2f/wot-f2f-beijing-scripting-api.md#localdiscovery

A factory method needs to be added to the WoT object to enable discovering exposed things on the same runtime in order to interact with them using server-side API

[zolkis]

Alternatively, going by the wording you have used, should we have a formal abstraction for "runtime" in WoT? Also, specify what is the relationship between Thing and runtime? Runtime contains multiple Things?

I ask because for similar reasons OCF uses the notion of "Device" (corresponding to a "runtime") and "Resource" (corresponding to a Thing). Resources are addressed by specifying a device id (that uniquely maps to a network address) and a resource id or path (that uniquely maps a resource within that device). When device id is not specified, requests are relevant to the same runtime.

Also, OCF mandates that every device implements a resource for supporting resource discovery. When you retrieve that resource, it lists all resources supported by that device.

I wonder if we need to introduce similar concepts in WoT, or otherwise how do we formally describe this.

If Thing is the only addressable entity in WoT, and runtime is a non-exposed abstraction, we may be able to get away with specifying a "local" parameter to the discovery function. But then every Thing implementation needs to replicate all infrastructure needed for discovery within a runtime. In that case we don't have a problem, local and remote discovery use the same mechanism.

[zolkis]

Actually there is a requirement to support GET on the Thing externally addressable root URL and provide a TD.

So is it correct to we assume a script running in the Thing is able to access the same information (i.e. no separate mechanism needed)?

[egekorkan]

Closing, the discussion should continue in w3c/wot-scripting-api#227