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Re: JSON-LD - experimenting with universal Linked Data markup for Web Services

From: Manu Sporny <msporny@digitalbazaar.com>
Date: Sun, 30 May 2010 12:18:47 -0400
Message-ID: <4C028FE7.4050102@digitalbazaar.com>
To: Public RDFa <public-rdfa@w3.org>
On 05/30/2010 05:04 AM, Michael Hausenblas wrote:
>>> On May 29th 2010, Manu Sporny tweeted:
>>> Just published JSON-LD:
>>>    http://rdfa.digitalbazaar.com/specs/source/json-ld/
>>> Universal markup of #rdfa #microdata and #microformats via
>>> lightweight JSON. #html5 #json #lod
> 
> Nice work! How does this relate to the linked-data-api [1], which already
> has a huge momentum and initial success is evident. 

I didn't know it existed until Jeni let me know about it today via a
tweet-back. :)

Some initial thoughts on it:

* "format" - this shouldn't exist. It is JSON, that's the format.
* "version" - I'm starting to drink the WHAT WG "no versioning" kool
              aid - don't see why there should be a version for a JSON
              and RDF language.
* Deeply nested structures are difficult to read - avoid at all costs.
* _about, _id, _value, _lang, _datatype - we should stay away from
  using commonly used words as predicates.
* We shouldn't have to expose RDF concepts like "datatype" and "lang"
  and "id" with special markup k-v pairs.
* It seems overly complicated and suffers from the same deeply-nested
  structures as JSON/RDF.

> If it's more or less the same, I'd suggest to join forces with 
> Jeni et al, if not, the differences should be made explicit.
> [1] http://code.google.com/p/linked-data-api/

Unfortunately, I don't think it's more or less the same. The JSON
serializatin of Linked Data API suffers from the same complexity that
JSON/RDF does - in that it isn't designed for JSON. It seems as if the
design started from RDF and serialized to JSON.

The design of JSON-LD didn't start with RDF. It started with the basic
premise that people like JSON because it is simple and terse and that
there are three markup languages for structured data at the moment -
RDFa, Microformats and Microdata.

The problem was figuring out how to map JSON's key-value model to Linked
Data formats (like RDFa, Microformats and Microdata). Directly mapping
RDF to JSON was a nice side-effect of creating a universal markup
mechanism... but directly mapping RDF (_id, _datatype, _lang, _about) to
JSON was not the primary goal.

The end result is a markup syntax that is more JSON than it is RDF...
and that's a good thing. :)

-- manu

-- 
Manu Sporny (skype: msporny, twitter: manusporny)
President/CEO - Digital Bazaar, Inc.
blog: Bitmunk 3.2.2 - Good Relations and Ditching Apache+PHP
http://blog.digitalbazaar.com/2010/05/06/bitmunk-3-2-2/2/
Received on Sunday, 30 May 2010 16:19:16 UTC

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