JSON, Rights and Linked Data for News: the Latest IPTC Meeting

What is the best way to represent news using JSON? How can publishers convey rights metadata, to make automatic publishing more efficient? What role does linked data play in improving the production and consumption of news?

In June 2013, publishers from around the world gathered at the IPTC face-to-face meeting in Paris - graciously hosted by the AFP - to discuss these and other topics.

Saint Eutache by mamsuco
http://www.flickr.com/photos/millets100fs/3559017612/

News in JSON

JSON is a lightweight format which continues to gain in popularity and tool support. The IPTC has therefore undertaken an effort to define the best way to represent key news properties using this technology. Although we could automatically translate from one of IPTC's existing XML standards into JSON, we believe it is better to create a spec for news properties in a way that results in more "natural" JSON. Find out what we're proposing via my latest News in JSON slides, which discuss the current NINJS draft.

Rights Metadata

There is a lot of interest amongst publishers of all sizes in expressing rights metadata, particularly for photos. Presently, most publishers need to have editors read the notes associated with each photo, to find out if there are any restrictions they should observe. The promise of machine-readable rights metadata is to make this a more efficient process: for example, to be able to automatically detect when an editor needs to decide whether to use a particular piece of content, rather than examining every photo, just in case.

I've been leading an effort within the IPTC to create RightsML specifically to support publishing industry requirements, based on the general-purpose W3C Community Group standard ODRL framework. In March 2013, we organized a one day conference with representatives from publishers, news agencies, photographers trade associations, law firms and standards bodies to examine the question: how can technology help assert and protect the rights of content creators? Find out more about that discussion, including video of the presentations. We are now focused on driving adoption of the RightsML standard, with better documentation and examples.

photographer by liz west
http://www.flickr.com/photos/calliope/1430290427/

Embedding Rights in Photos

ODRL and hence RightsML has a data model with a well-defined representation in XML. However, many producers of photos would rather have the rights expressed inside the binaries themselves, rather than - or in addition to - having an XML "sidecar". (That's in part because many photo workflows discard any other files and just work with the photos themselves). The challenge is what format to use? Our experiments with trying to embed either RDF or XML within XMP didn't work.So, now we're looking at expressing ODRL in JSON.

NewsML-G2

Currently, NewsML-G2 is the IPTC's flagship standard for news exchange. It continues to evolve, with a full production release each year (and "developer" releases in between). At this meeting, APA unveiled a new perl library to make it easier to produce G2. And we learnt about a major effort to compare the details of NewsML-G2 production by major providers, with the goal of harmonizing them, to make it easier for our customers.

Harmony Roof Sculpture - Opera Garnier - Palais Opera by ell brown
http://www.flickr.com/photos/ell-r-brown/3772502193/

Linked Data and the Semantic Web

We heard about interesting progress from the BBC on using rNews and the Storyline Ontology to enrich the presentation of news on the web. The AFP's medialab showed innovative news prototypes, also leverage rNews, including one for extracting quotes by politicians on various topics. And we at the AP discussed some of the details behind our Metadata Services offering.

Join Us

As well as updates on standards and practical sharing of industry information, the once-a-year AGM is when the IPTC updates its policies. At the Paris meeting, we decided to add an additional level of membership: now individuals can join the group, making it easier for people to participate in the standards used by the news industry and allowing them to attend these kinds of face-to-face meetings. Contact the IPTC Office for more information.

XML Namespaces

If you only take away one thing from this blog posting, let it be this:

XML Protip:

If you can’t figure out why your XPath expression isn’t working, check the namespace.

XML Namespaces

It is possible to define XML elements and attributes in different namespaces.
This promotes reuse of existing vocabularies because, rather than copying someone else's elements and attributes into your schema, you can just directly incorporate their XML vocabulary into your instance documents.

Namespaces Look Like URLs

XML Namespaces look like URLs, although there is no requirement that there be anything in particular that you can retrieve at the end of the URL. But URLs are convenient because they are a well-established way to have a federated naming scheme. In other words, if I own an Internet domain, I can make up URLs within that domain without needing to consult any centralized authority. That means I can use URLs to mint new, guaranteed unique namespace identifiers.

Declaring Namespaces

You can use xmlns to declare a default namespace

<newsItem xmlns='http://iptc.org/std/nar/2006-10-01/'>

  <itemMeta>
    <title>Pope Blesses Astronauts</title>

  </itemMeta>
</newsItem>

In the above example, newsItem is in the http://iptc.org/std/nar/2006-10-01 namespace.
itemMeta and title are also in the http://iptc.org/std/nar/2006-10-01/ namespace, even though they don't have any xmlns listed on the elements. That's because child elements inherit the namespace from their parents.

XML Namespace Prefixes

You can use xmlns:prefix to declare a namespace and bind it to a prefix

<nar:newsItem xmlns:nar='http://iptc.org/std/nar/2006-10-01/'>
  <nar:itemMeta>
    <nar:title>Pope Blesses Astronauts</nar:title>
  </nar:itemMeta>
</nar:newsItem>

newsItem is in the http://iptc.org/std/nar/2006-10-01/ namespace. And so are itemMeta and title: to an XML parser, this document and the previous one are identical.

Whether you use a prefix on each namespaced element or you leave them unadorned is a matter of style and personal preference.

Namespace are Useful, but can be Confusing

Although namespaces are important in constructing modular XML documents and avoiding re-inventing the wheel of vocabularies, they can be quite confusing. In particular, the non-prefix syntax (in which an element inherits its namespace from its parent) can catch you out in various ways.

For example, if you were to just copy and paste the "inner" markup from the first document above, you'd wind up with the document below - and lose the namespace!

  <itemMeta>
    <title>Pope Blesses Astronauts</title>

  </itemMeta>

This is bad.

Similarly, it is routine to look at an instance document and construct an XPath such as this to pick out the value of the title element:

itemMeta/title


And spend hours trying to figure out why it isn't working. Of course, you know that it is because we didn't specify that the itemMeta  and  title elements need to be in the http://iptc.org/std/nar/2006-10-01/ namespace.


Hence my number one tip for debugging XML-related code:

XML Protip:

If you can’t figure out why your XPath expression isn’t working, check the namespace.

Updated

Paul Kelly adds his number one XPath tip: check the spelling first.