W3C home > Mailing lists > Public > public-linked-json@w3.org > June 2011

Re: JSON-LD Basic

From: Gregg Kellogg <gregg@kellogg-assoc.com>
Date: Sat, 25 Jun 2011 16:24:46 -0400
To: Manu Sporny <msporny@digitalbazaar.com>
CC: Linked JSON <public-linked-json@w3.org>
Message-ID: <BCE8B6D5-2083-4E83-A7FC-3ADAC87836EC@kellogg-assoc.com>
Some things need to be more explicit, and we need to be careful that a document evaluated as JSON-LD Basic will have the same meaning when evaluated as JSON-LD Advanced.

The document doesn't specify the range of terms used within a mapping. All examples are simple strings, that may be evaluated as IRIs if there's an @coerce mapping. However, the @type example definitely shows the use of an array to map multiple values to a particular key.

If a value is determined to be an IRI, it may be a relative IRI or term (no CURIEs in JSON-LD Basic). If it is a relative IRI, what is it evaluated with respect to? For most objects, I'd expect it to be relative to the document's URL, but what if a @context contains a @base definition for JSON-LD Advanced? Is there such a thing? Perhaps we need to specify that a JSON-LD Basic document MUST NOT be used with a JSON-LD Advanced @context, to avoid this confusion. We should have some formal language for evaluating values and IRIs. In the current (advanced) spec [1], this includes a description of using @base or @vocab to evaluate a relative IRI, depending on the context.

Should JSON-LD Basic have any notion of chaining, or is it intended to be an entirely flat model? What about anonymous items? (No named-BNode rat-hole please). Some form of chaining is common in JSON documents in the wild.

The documentation on Subject indicates that the value should (or SHOULD) be a dereferencable URL. I presume this is true for other IRI property values as well. What about values with fragids? Does this imply some index into the referenced document, perhaps to an item that has an equivalent IRI definition. This follow-your-nose concept is basically what Kingsley's been asking for, I believe.

Gregg

[1] http://json-ld.org/spec/ED/20110615/#iri-processing

On Jun 23, 2011, at 11:07 PM, Manu Sporny wrote:

> Glenn, Brian, Kingsley,
> 
> Is this more along the lines of what you had in mind?
> 
> http://json-ld.org/spec/latest/basic/
> 
> Pay particular attention to Section 3: JSON-LD Basic Keywords
> 
> I think that may be all we need for the use cases each of you is
> describing. Note that this does not remove the need for JSON-LD Advanced
> (and all of the RDF mapping stuff that will need to go on in that
> specification).
> 
> -- manu
> 
> -- 
> Manu Sporny (skype: msporny, twitter: manusporny)
> President/CEO - Digital Bazaar, Inc.
> blog: PaySwarm Developer Tools and Demo Released
> http://digitalbazaar.com/2011/05/05/payswarm-sandbox/
> 
> 
Received on Saturday, 25 June 2011 20:25:44 GMT

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