POWDER Processor

Get a description of a URI
Clear Cache
(If no POWDER document is specified, the processor will use the data in its cache to provide a description if possible.)
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RDF output

<?xml version="1.0"?>
<rdf:RDF
  xmlns:rdf="http://www.w3.org/1999/02/22-rdf-syntax-ns#"
  xmlns:rdfs="http://www.w3.org/2000/01/rdf-schema#"
  xmlns:wdrs="http://www.w3.org/2007/05/powder-s#"
  xmlns:ex="http://example.org/vocab#">

  <rdf:Description rdf:about="http://example.com/">
    <ex:colour>#f00</ex:colour>
    <wdrs:text xml:lang="en">Red</wdrs:text>
    <wdrs:text xml:lang="fr">Rouge</wdrs:text>
    <wdrs:text xml:lang="de">Rot</wdrs:text>
    <wdrs:text xml:lang="nl">rood</wdrs:text>
    <wdrs:tag xml:lang="en">Red</wdrs:tag>
    <wdrs:tag xml:lang="fr">Rouge</wdrs:tag>
    <rdfs:label xml:lang="en">A tag for (red) and those odd { characters ! shouldn&apos;t cause a problem | should they?</rdfs:label>
    <rdfs:comment xml:lang="en">This really is red</rdfs:comment>
    <rdfs:comment xml:lang="fr">C&apos;est rouge n&apos;est pas?</rdfs:comment>
    <wdrs:describedby rdf:resource="http://philarcher.org/powder/xslt/multi_lingual.xml" />
  </rdf:Description>

  <rdf:Description rdf:about="http://philarcher.org/powder/xslt/multi_lingual.xml">
    <wdrs:issuedby rdf:resource="http://authority.example.org/company.rdf#me" />
  </rdf:Description>

</rdf:RDF>

This tool is designed to show how POWDER can be used, returning an RDF description of a given resource dervied from a given POWDER document as a data source.

Using the processor

Using the processor as a demonstrator should be simple enough. Enter a candidate URI (the URI to be described) and the URI of a POWDER document that describes it. Submitting the form will return a description either as RDF or as an HTML page that shows the RDF that would be returned (depending on the output option is selected).

The example files in the Description Resources document can be chosen from the drop down menu but if the URI of a POWDER document, this choice is ignored.

If no POWDER document is specified then the processor will use the data already available in its cache to describe the candidate URI (if it can).

This behaviour differs from Andrea Perego's POWDER Processor. If no POWDER document is supplied as a date source, his processor will visit the candidate URI and follow any Link elements to discover associated POWDER documents.

Two simple HTML documents are also provided here that demonstrate the use of u=referer when linking to a processor that then returns a description of that document. One uses a DR with a defined IRI set, the other refers directly to its description in line with Section 2.6 of the Description Resources document.

As part of its function, the processor caches POWDER documents. The Clear Cache button will clear the cache of all data that has been uploaded during your tests (and it all gets cleared out regularly anyway).

See also the Validator with which this processor shares some of its code.

To Do

Phil Archer
19 April 2010
on behalf of i-sieve Technologies.