Re: [TF-TD] experimenting with mapping JSON based data models to RDF triples

> On 8 Jan 2016, at 10:13, Charpenay, Victor (ext) <victor.charpenay@siemens.com> wrote:
> 
> Hi Dave, hi everybody,
>  
> I’m not sure I understood your idea behind this experiment. To which extent is your algorithm different from the deserialization specified in the JSON-LD API document [1]?

This is something I am looking at, e.g. in respect to the use of paths to disambiguate names.  The motivation is to see whether we can create an easier to process and a more appealing format for object data models rather than taking a reductionist approach to RDF triples and the open world assumption. Your help in this study would be much appreciated.

>  
> With jsonld.js (used in the JSON-LD playground [2]), we have a quite similar result. The following JSON object (one of your tests):
> {
>   "@context": {
>     "@vocab": "coap://example.org/mything/ <coap://example.org/mything/>"
>   },
>   "properties": {
>     "on" : {
>       "type" : "boolean",
>       "writeable": true
>     },
>     "working" : "boolean"
>   }
> }
>  
> becomes:
> _:b0 <coap://example.org/mything/properties <coap://example.org/mything/properties>> _:b1 .
> _:b1 <coap://example.org/mything/on <coap://example.org/mything/on>> _:b2 .
> _:b1 <coap://example.org/mything/working <coap://example.org/mything/working>> "boolean" .
> _:b2 <coap://example.org/mything/type <coap://example.org/mything/type>> "boolean" .
> _:b2 <coap://example.org/mything/writeable <coap://example.org/mything/writeable>> "true"^^<http://www.w3.org/2001/XMLSchema#boolean <http://www.w3.org/2001/XMLSchema#boolean>> .
>  
> The only difference is I added a default namespace for keys. One could imagine this namespace corresponds to the address of the thing we describe or the exact URI of the document. It can of course be combined with the proposed default WoT @context.
>  
> I wish you all a happy new year.
> Best regards,
> Victor
>  
> [1] http://www.w3.org/TR/json-ld-api/#rdf-serialization-deserialization-algorithms <http://www.w3.org/TR/json-ld-api/#rdf-serialization-deserialization-algorithms>
> [2] http://json-ld.org/playground/ <http://json-ld.org/playground/>
>  
>  
> From: Dave Raggett [mailto:dsr@w3.org] 
> Sent: Dienstag, 29. Dezember 2015 12:38
> To: Drasko DRASKOVIC
> Cc: public-web-of-things
> Subject: Re: [TF-TD] experimenting with mapping JSON based data models to RDF triples
>  
>  
> On 29 Dec 2015, at 01:52, Drasko DRASKOVIC <drasko.draskovic@gmail.com <mailto:drasko.draskovic@gmail.com>> wrote:
>  
> Hi Dave,
> 
> On Mon, Dec 28, 2015 at 5:22 PM, Dave Raggett <dsr@w3.org <mailto:dsr@w3.org>> wrote:
> 
> To attract Web developers to working with the Web of Things we need simple
> notations for describing the properties, actions and events for things.
> Simple notations are also needed for Web of Things servers on resource
> constrained microcontrollers.
> 
> Data models are one kind of metadata for things, and we also need a way to
> map these models to the underlying resource description framework (RDF).
> 
> JSON-LD [1] is appealing due to its use of the very popular JavaScript
> Object Notation (JSON).  However, JSON-LD wasn’t designed with thing data
> models in mind. I have therefore been exploring the implications for
> translating JSON based data models to RDF triples.
> 
> My experiments are in the form of a Web page that expresses the algorithm in
> JavaScript.
> 
>    http://www.w3.org/2016/01/json2rdf.html <http://www.w3.org/2016/01/json2rdf.html>
> 
> I would like to request some time at an upcoming Thing Description task
> force call to introduce this work and talk through the questions that arise.
> These include:
> 
> How to survey the Web developer community for their opinions
> The role of paths for uniquely naming fields in thing data models
> Allowing for deeply nested data models for properties, actions and events
> Processing implications for different approaches for representing data
> models
> The role of open versus closed world hypothesis for thing data models
> How to address versioning — something critical for web scale services
> 
> I know that we had similar discussion before, but did you take a look
> at CoRE format: https://tools.ietf.org/html/rfc6690? <https://tools.ietf.org/html/rfc6690?>
>  
> Yes, I have, and there are many other serialisations for RDF, e.g. Turtle, N3, RDF-XML, binary encodings of triples and so forth. But, it isn’t just about RDF, for the Web of Things we need solutions for declaring the data models exposed to applications. These needs to be simple and appealing to Web developers. We also need to consider the processing implications for resource constrained devices including low-end microcontrollers. I welcome a discussion on this as I don’t think that any of the existing solutions are a good fit.
>  
> —
>    Dave Raggett <dsr@w3.org <mailto:dsr@w3.org>>

—
   Dave Raggett <dsr@w3.org <mailto:dsr@w3.org>>