July 9, 2008

Changes to SearchMonkey's DataRSS format

In our continued effort to search for the right balance between simplicity and expressiveness, we are revising some aspects of the DataRSS format used by SearchMonkey applications. As a first step, we have made it possible to provide a space-separated list of compact URIs as part of the rel and property attributes instead of providing a single value. This is to support situations where there are multiple properties (possibly from different vocabularies) expressing the proper relationship or there are multiple relationships to begin with. For example, mixing the FOAF and VCard vocabularies you may write


<item rel="dc:subject rel:Card">

  <meta property="vcard:fn foaf:name">Peter Mika</meta>

  <item rel="foaf:knows xfn:co-worker">

       <meta property="vcard:fn foaf:name">Amit Kumar</meta>

  </item>

</item>


By providing support for a space-separated lists of compact URIs (CURIEs), we are bringing dataRSS closer to RDFa, which also allows multiple values for the property and rel attributes.

The microformat data we generate now also features space separated lists of CURIEs as in the above example. Note that presentation applications using Data::xpath and checking for the presence of a certain CURIE using equivalence ('=' in XPath) instead of containment (contains function in XPath) may fail. If your application used Data::xpath and uses microformat data from the index, you may need to update your application.

As a next step, we will introduce support for the 'typeof' attribute of RDFa. For the moment, typing is explicit in DataRSS: in the above example, rel:Card is a property that expresses that the type of the item is a VCard. Based on the analysis of current usage it seems that this is confusing for many SearchMonkey developers and we need a clearer separation between types and properties. We will report on this improvement when it becomes available.

As always, your feedback is welcome. Please consider providing comments on existing features using our mailing list or proposing new features using the suggestions board.

Peter Mika
Data Architect for SearchMonkey

Posted at July 9, 2008 12:04 PM | Permalink

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Posted by: Sam at July 9, 2008 12:49 PM