Re: Use of full URI for rdf:type instead of @type

On 05/09/2014 03:49 PM, Gregg Kellogg wrote:
> On May 9, 2014, at 7:38 AM, john.walker <john.walker@semaku.com> wrote:
> 
>> For sake of completeness here is another example of the JSON-LD tree using
>> "@type" [4] working with the first frame [2]:
>> http://json-ld.org/playground/index.html#startTab=tab-framed&json-ld=https%3A%2F%2Frawgit.com%2Fjaw111%2Fbbd1b00d656045ba8a2c%2Fraw%2Ftree2.jsonld&frame=https%3A%2F%2Frawgit.com%2Fjaw111%2Fbbd1b00d656045ba8a2c%2Fraw%2Fframe1.jsonld&context=%7B%7D
>>
>> But same input does not get along with second frame [3]:
>> http://json-ld.org/playground/index.html#startTab=tab-framed&json-ld=https%3A%2F%2Frawgit.com%2Fjaw111%2Fbbd1b00d656045ba8a2c%2Fraw%2Ftree2.jsonld&frame=https%3A%2F%2Frawgit.com%2Fjaw111%2Fbbd1b00d656045ba8a2c%2Fraw%2Fframe2.jsonld&context=%7B%7D
> 
> Hi Jon, a couple of things to note:
> 
> 1) JSON-LD treats rdf:type like @type only when importing from RDF; otherwise, it's just another property.
> 
> 2) Framing is really pattern matching. For a frame to match @type: skos:ConceptScheme, it has to be specified using @type in the input JSON-LD.
> 
> You could get this effect by first transforming the input to RDF, and then back to JSON-LD to have it use @type. For example, see the following: http://goo.gl/JILxnc.

Alternatively, I think you could also specify
"http://www.w3.org/1999/02/22-rdf-syntax-ns#type" as an alias for @type
to get the desired effect:

{
  "@context": {
    "http://www.w3.org/1999/02/22-rdf-syntax-ns#type": "@type"
  }
}

> 
> 
>>> On May 9, 2014 at 4:27 PM "john.walker" <john.walker@semaku.com> wrote:
>>>
>>>
>>> Hi There,
>>>  
>>> I have a question about use of rdf:type in JSON-LD.
>>>  
>>> Take for example a simple SKOS tree loaded [1] to the playground:
>>> http://json-ld.org/playground/index.html#json-ld=https%3A%2F%2Frawgit.com%2Fjaw111%2Fbbd1b00d656045ba8a2c%2Fraw%2Ftree.jsonld
>>>  
>>> All looks good.
>>>  
>>> Now I want to apply a JSON-LD frame [2] to this:
>>> http://json-ld.org/playground/index.html#startTab=tab-framed&json-ld=https%3A%2F%2Frawgit.com%2Fjaw111%2Fbbd1b00d656045ba8a2c%2Fraw%2Ftree.jsonld&frame=https%3A%2F%2Frawgit.com%2Fjaw111%2Fbbd1b00d656045ba8a2c%2Fraw%2Fframe1.jsonld
>>>
>>> In the result there is no content in the "@graph".
>>>
>>> It seems that this is due to the use of "@type" in the JSON-LD frame, whereas
>>> the JSON-LD input uses "http://www.w3.org/1999/02/22-rdf-syntax-ns#type".
>>>
>>> Note that the input document is being generated from a SPARQL query, so I'm
>>> not
>>> in control of how it is formed, it's just a simple serialization of the
>>> triples.
>>>
>>> So a triple in question looks like:
>>>
>>> {
>>>    "@id": "http://example.com/conceptSchemes/myTree",
>>>    "http://www.w3.org/1999/02/22-rdf-syntax-ns#type": {
>>>      "@id": "http://www.w3.org/2004/02/skos/core#ConceptScheme"
>>>    }
>>> }
>>>
>>> I would have thought the processor would somehow know that "@type" and
>>> "http://www.w3.org/1999/02/22-rdf-syntax-ns#type" are equivalent, but it seems
>>> not.
>>>
>>> If I modify the frame to use the full URI [3], it works as expected:
>>> http://json-ld.org/playground/index.html#startTab=tab-framed&json-ld=https%3A%2F%2Frawgit.com%2Fjaw111%2Fbbd1b00d656045ba8a2c%2Fraw%2Ftree.jsonld&frame=https%3A%2F%2Frawgit.com%2Fjaw111%2Fbbd1b00d656045ba8a2c%2Fraw%2Fframe2.jsonld
>>>
>>> So my questions:
>>> - is this specified on way or another in the standard
>>> - is this a problem in the processing in the playground, or
>>> - should the relevant triples be formulated as follows in the JSON-LD input:
>>>
>>> {
>>>    "@id": "http://example.com/conceptSchemes/myTree",
>>>    "@type": "http://www.w3.org/2004/02/skos/core#ConceptScheme"
>>> }
>>>
>>> Hope that is clear...
>>>
>>> Cheers,
>>> John
>>>
>>> [1] https://rawgit.com/jaw111/bbd1b00d656045ba8a2c/raw/tree.jsonld
>>> [2] https://rawgit.com/jaw111/bbd1b00d656045ba8a2c/raw/frame1.jsonld
>>> [3] https://rawgit.com/jaw111/bbd1b00d656045ba8a2c/raw/frame2.jsonld
>>>
>>
>> John
>>
>> [4] https://rawgit.com/jaw111/bbd1b00d656045ba8a2c/raw/tree2.jsonld
>>
> 
> 


-- 
Dave Longley
CTO
Digital Bazaar, Inc.

Received on Friday, 9 May 2014 20:33:15 UTC