Thing Description and thingschema

Hi Sebastian,

Thanks for the pointers to the TD resources. 

It looks like we have a lot in common around the JSON-LD schema and model work.

I have some questions about the thing description like where to find the definitions 
of terms like “links”, “actionStatus”, “createdTime”, etc. that appear in the 
examples. Also whether there are hyperlinks pointing to resources like
/ledlamp/colorTemperature/value <http://www.example.com:5683/ledlamp/colorTemperature/value>

As part of my demo, I’ve put up a public resource at thingschema.org with the 
context, schemas and models I’m using which bear a lot of similarity to some 
of the TD language constructs. 

This definition in the TD context follows the same pattern I’m using for events,
actions, and properties.
"interactions": {
  "@id": "td:hasInteraction",
  "@type": "@id",
  "@container": "@set”
},
This leads into a good illustration of creation of semantic triples from JSON models.
Here is part of the context at http://thingschema.org/context.jsonld <http://thingschema.org/context.jsonld>
which is also mapped to http://thingschema.org/ <http://thingschema.org/>
 
"capabilities”: {
  "@id": "ts:hasCapability”, 
  "@type": "@id”
},
"events": {
  "@id": "ts:hasEvent”, 
  "@type": "@id”
},
"actions": {
  "@id": "ts:hasAction”, 
  "@type": "@id"},
"properties": {
  "@id": "ts:hasProperty”, 
  "@type": "@id”}

I found that I needed a way to define components of things so I defined “capabilities”. 
For example the on/off control of a light is one capability and brightness control is 
another. So in the model I can define “actions” for a thing (or a capability of a thing), 
and “properties” and “events” of a thing in terms of the domain schema.

Here is a sample from the JSON-LD model for the light, which starts as plain JSON and
which, with the addition of the @context definition at thingschema.org <http://thingschema.org/>, can be used to 
generate an RDF model.

{
  "@context": "http://thingschema.org",
  "label": "light",
  "resource": [
    {
      "type": “light",
      "name": "light",
      "capabilities": [
        {
          "type": "onoff",
          "name": "onOff",
          "actions": [
            {
              "type": "change",
              "name": "change"
            }
          ],
          "properties": [
            {
              "type": "currentstate",
              "name": "currentState"

Which produces the following machine-comprehensible RDF model:

_:b0 <http://www.w3.org/2000/01/rdf-schema#Resource> _:b1 .
_:b0 <http://www.w3.org/2000/01/rdf-schema#label> "light" .
_:b1 <http://thingschema.org/name> "light" .
_:b1 <http://thingschema.org/schema#hasCapability> _:b2 .
_:b1 <http://thingschema.org/schema#hasCapability> _:b7 .
_:b1 <http://thingschema.org/schema#hasCapability> _:b9 .
_:b1 <http://www.w3.org/1999/02/22-rdf-syntax-ns#type> <http://thingschema.org/light> .
_:b10 <http://thingschema.org/name> "change" .
_:b10 <http://www.w3.org/1999/02/22-rdf-syntax-ns#type> <http://thingschema.org/change> .
_:b11 <http://thingschema.org/name> "move" .
_:b11 <http://www.w3.org/1999/02/22-rdf-syntax-ns#type> <http://thingschema.org/move> .
_:b12 <http://thingschema.org/name> "step" .
_:b12 <http://www.w3.org/1999/02/22-rdf-syntax-ns#type> <http://thingschema.org/step> .
_:b13 <http://thingschema.org/name> "currentBrightness" .
_:b13 <http://www.w3.org/1999/02/22-rdf-syntax-ns#type> <http://thingschema.org/currentbrightness> .
_:b14 <http://thingschema.org/name> "targetBrightness" .
_:b14 <http://www.w3.org/1999/02/22-rdf-syntax-ns#type> <http://thingschema.org/targetbrightness> .
_:b15 <http://thingschema.org/name> "moveBrightness" .
_:b15 <http://www.w3.org/1999/02/22-rdf-syntax-ns#type> <http://thingschema.org/movebrightness> .
_:b16 <http://thingschema.org/name> "stepBrightness" .
_:b16 <http://www.w3.org/1999/02/22-rdf-syntax-ns#type> <http://thingschema.org/stepbrightness> .
_:b17 <http://thingschema.org/name> "transitionTime" .
_:b17 <http://www.w3.org/1999/02/22-rdf-syntax-ns#type> <http://thingschema.org/transitiontime> .
_:b2 <http://thingschema.org/name> "onOff" .
_:b2 <http://thingschema.org/schema#hasAction> _:b3 .
_:b2 <http://thingschema.org/schema#hasProperty> _:b4 .
_:b2 <http://thingschema.org/schema#hasProperty> _:b5 .
_:b2 <http://thingschema.org/schema#hasProperty> _:b6 .
_:b2 <http://www.w3.org/1999/02/22-rdf-syntax-ns#type> <http://thingschema.org/onoff> .
_:b3 <http://thingschema.org/name> "change” .

(etc.)

You can play with the schemas and full model using the JSON-LD playground:
http://json-ld.org/playground/ <http://json-ld.org/playground/>

Context:
http://thingschema.org/context.jsonld <http://thingschema.org/context.jsonld>

WoT Schema:
http://thingschema.org/wot.jsonld <http://thingschema.org/wot.jsonld>

Domain Schema for light:
http://thingschema.org/light.jsonld <http://thingschema.org/light.jsonld>

Model for light:
http://thingschema.org/lightmodel.jsonld <http://thingschema.org/lightmodel.jsonld>

In my demo, the model is used to construct the hypermedia controls for the resources 
the server exposes which implement Events, Actions, Properties, and Capabilities. 
The client only needs the hypermedia controls, but may use the schema if needed to 
help identify terms and relationships in the hypermedia controls.

The developer only needs to know JSON and the keywords in the context and schema like 
“actions” to define models, and the application script developer can use terms from 
the schema to drive discovery.

The schemas are actually ontologies with simple typed links “mayHave" and “usedBy”
but could of course be enriched with additional relation types.

This is one of a few topics I will be demonstrating next week.

Best regards,

Michael.