RDFa API - adding Namespace

Tim Berners-Lee wrote:
> The way the namespaces work I think is nice,
> You say foaf =  $rdf.Namespace("http://....");
> data.add(me, foaf('name'), you);
> Now I'd make it "ns" rather than Namespace in the spirit of making it all fairly compact.

Tim, Mark, Ivan, All,

This is a "minimal change" proposal to add tabulators Namespace 
functionality in to the RDFa API, together with the use-case which 
hopefully warrants it's inclusion.

I propose we change the definition of DataContext setMapping to be:

interface DataContext {
     CurieResolver setMapping (in DOMString prefix, in DOMString iri);

and add the following interface:

[NoInterfaceObject Callback]
interface CurieResolver {
     IRI resolve (in DOMString curie);

This has minimal impact on the RDFa API but makes it much more usable, 
usage is as follows:

   var foaf = context.setMapping('foaf', 'http://xmlns.com/foaf/0.1/');
   foaf('name'); // returns IRI('http://xmlns.com/foaf/0.1/name')

To illustrate how useful this is, here are two versions of the 
javascript required to create the following triples:

   :me a foaf:Person;
     foaf:givenname "Nathan";
     foaf:homepage <http://webr3.org/>;
     foaf:knows :bob, :sue.

with this proposal:

   var t1 = data.createTriple(me, rdf('type') , foaf('Person') );
   var t2 = data.createTriple(me, foaf('givenname') , myName );
   var t3 = data.createTriple(me, foaf('homepage') , myHomepage );
   var t4 = data.createTriple(me, foaf('knows') , thisDoc('bob') );
   var t5 = data.createTriple(me, foaf('knows') , thisDoc('sue') );

without the proposal (current API usage):
   var t1 = data.createTriple(me, data.context.resolveCurie('rdf:type') 
, data.context.resolveCurie('foaf:Person') );
   var t2 = data.createTriple(me, 
data.context.resolveCurie('foaf:givenname') , myName );
   var t3 = data.createTriple(me, 
data.context.resolveCurie('foaf:homepage') , myHomepage );
   var t4 = data.createTriple(me, 
data.context.resolveCurie('foaf:knows') , 
data.context.resolveCurie(':bob') );
   var t5 = data.createTriple(me, 
data.context.resolveCurie('foaf:knows') , 
data.context.resolveCurie(':sue') );

I sincerely hope that illustrates how beneficial this would be to add, 
and as a bonus it keeps the entire API type safe with no additional 
changes needed.



ps: here's the snipped code which makes the above examples work (remove 
the `var = thisDoc` etc for the usage without this change):

   var thisDoc = data.context.setMapping( "" , "http://webr3.org/nathan#" );
   var rdf = data.context.setMapping( "rdf" , 
"http://www.w3.org/1999/02/22-rdf-syntax-ns#" );
   var foaf = data.context.setMapping( "foaf" , 
"http://xmlns.com/foaf/0.1/" );

  var me = data.context.resolveCurie(':me');
  var myName = data.createPlainLiteral("Nathan");
  var myHomepage = data.createIRI("http://webr3.org/");

Received on Saturday, 9 October 2010 17:45:35 UTC