Posted by Shane Becker on
Today I learned about a proposed spec called JSON-LD. The âLDâ is for linked data (Linked Data⢠in the Uppercase âSâ Semantic Web sense).1
From the JSON-LD site:
Data is messy and disconnected. JSON-LD organizes and connects it, creating a better Web.
Linked Data empowers people that publish and use information on the Web. It is a way to create a network of standards-based, machine-readable data across Web sites. It allows an application to start at one piece of Linked Data, and follow embedded links to other pieces of Linked Data that are hosted on different sites across the Web.
JSON-LD is a lightweight Linked Data format. It is easy for humans to read and write. It is based on the already successful JSON format and provides a way to help JSON data interoperate at Web-scale. JSON-LD is an ideal data format for programming environments, REST Web services, and unstructured databases such as CouchDB and MongoDB.
Linked data. Web sites. Standards. Machine readable.
Cool. All of those sound good to me. But they all sound familiar, like weâve already done this before. In fact, we have.
Linked data
Thatâs just the web, right? I mean, weâve had the <a href> tag since literally the beginning of HTML / The Web. Itâs for linking documents. Documents are a representation of data.
Web sites
If itâs not wrapped in HTML and viewable in a browser it, is it really a website? JSON isnât very useful in the browser by itself. Itâs not style-able. Itâs not very human-readable. And worst of all, itâs not clickable.2
Standards based
To their credit, JSON-LD did license their website content Creative Commons CC0 Public Domain. But, the spec itself isnât. Itâs using (what seems to be) a W3C boilerplate copyright / license. Copyright Š 2010-2013 W3CÂŽ (MIT, ERCIM, Keio, Beihang), All Rights Reserved. W3C liability, trademark and document use rules apply. (source)
Machine readable
Ah⌠âmachine readableâ. Every couple of years the current trend of what machine readable data should look like changes (XML/JSON, RSS/Atom, xml-rpc/SOAP, rest/WS-*). Every time, there are the same promises. This will solve our problems. It wonât change. Itâll be supported forever. Interoperability. And every time, they break their promises. Todayâs empires, tomorrowâs ashes.3
Instead of reinventing the everything (over and over again), letâs use whatâs already there and what already works. In the case of linked data on the web, thatâs html web pages with clickable links between them. For open standards, open license are a deal breaker. No license is more open than Creative Commons CC0 Public Domain + OWFa. (See also the Mozilla wiki about standards/license, for more.) Thereâs a growing list of standards that are already using CC0+OWFa. No process is more open than a publicly editable wiki. (Mailing lists are toxic.)
Finally, for machine readable data, nothing has been more widely adopted by publishers and consumers than microformats. As of June 2012, microformats represents about 70% of all of the structured data on the web. And of that ~70%, the vast majority was h-card and xfn. (All RDFa is about 25% and microdata is a distant third.)
Maybe itâs because of the ease of publishing microformats. Maybe itâs the open process for developing the standards. Maybe itâs because microformats donât require any additions to HTML. (Both RDFa and microdata required the use of additional attributes or XML namespaces.) Whatever the reason, microformats has the most uptake. So, why do people keep trying to reinvent what microformats is already doing well?
Back to JSON-LD. The âSimple Exampleâ listed on the homepage is a person object representing John Lennon. His birthday and wife are also listed on the object.
{
"@context": "http://json-ld.org/contexts/person.jsonld",
"@id": "http://dbpedia.org/resource/John_Lennon",
"name": "John Lennon",
"born": "1940-10-09",
"spouse": "http://dbpedia.org/resource/Cynthia_Lennon"
}
I look at this and see what should have been HTML with microformats (h-card and xfn). This is actually a perfect use case for h-card and xfn: a person and their relationship to another person. Hereâs how it couldâve been marked up instead.
<div class="h-card">
<a href="http://dbpedia.org/resource/John_Lennon" class="u-url u-uid p-name">John Lennon</a>
<time class="dt-bday" datetime="1940-10-09">October 9<sup>th</sup>, 1940</time>
<a rel="spouse" href="http://dbpedia.org/resource/Cynthia_Lennon">Cynthia Lennon</a>.
</div>
You can throw in a little bit of decoration for improved human readability without comprising machine readability.
<div class="h-card">
<a href="http://dbpedia.org/resource/John_Lennon" class="u-url u-uid p-name">John Lennon</a>
was born on
<time class="dt-bday" datetime="1940-10-09">October 9<sup>th</sup>, 1940</time>
and was married to
<a rel="spouse" href="http://dbpedia.org/resource/Cynthia_Lennon">Cynthia Lennon</a>.
</div>
This HTML can be easily understood by machine parsers and humans parsers. Microformats 2 parsers already exists for: JavaScript (in the browser), Node.js, PHP and Ruby. HTML + microformats2 means that machines can read your linked data from your website and so can humans. It means that you donât need an âAPIâ that is something other than your website.
Please donât waste time and energy reinventing all of the wheels. Instead, please use what already works and what works the webby way.
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In its footer, the JSON-LD site mentions that itâs a âPart of the PaySwarm standardization initiativeâ. Which in turns claims to be âThe Universal Payment Standardâ. An awfully big claim. But, thatâs another post for another time. ↩
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Hell! You canât even put comments in your JSON. ↩
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- 2005-2009(?): StructuredBlogging
- 2005-2011: Google Base schema
- 2007-2011(?): Google Data API/Elements
- 2009-2009(?): Yahoo et al CommonTag.org
- 2009-2011(?): Google rdf.data-vocabulary.org
- 2010-present Facebook OGP meta tags
- 2011-present Google+MS(Y!) Schema.org
- 2012-present Twitter Cards meta tags
- 2012-present OpenMetadata.org
(source: tantek.com)Â ↩