DataRSS
From FOAF Wiki
DataRSS is an Atom extension used by Yahoo's SearchMonkey system. Metadata is carried in the content element. The content consists of typically a singe adjunct (with metadata about the graph such as timestamp). Inside the adjunct there are item and meta elements, corresponding to resources and datatype-properties. The attributes of these elements come from RDFa and used in the same sense thus the format is also RDFa compatible (you can run an RDFa parser on it and get triples out). It can be combined with OpenSearch where some opensearch elements are also turned into metadata automatically.
If you want to wrap an API to be used by SM, you have to build a custom data service that either returns arbitrary XML, or returns DataRSS directly. In case you return arbitrary XML, you need to provide a stylesheet to transform it to DataRSS. (Thus if you control the service it's easier to return DataRSS directly.) When returning DataRSS it has to be valid Atom and the name attribute of the adjunct element has to be 'opensearch'. Note that custom data services can be chained: the results returned from one service can be as used input to another service. The limitation is that custom data services are currently executed runtime.
Cache control: the final results for presentation (ie. generated HTML) will be cached at Yahoo. This reduces load on DataRSS-generating services and improves responsiveness. Currently it is not known what hints (e.g. cache-control headers or markup) might be sent with the DataRSS to help improve caching behaviour.
See Yahoo's documentation for more details. SearchMonkey allows for the presentation of FOAF data within search results; the PHP doing this HTML generation may also call DataRSS Web services. Potentially, we could use this to wire-up Google's Social Graph API.
Further Reading:
* http://developer.yahoo.com/searchmonkey/smguide/understand_datarss.html * http://developer.yahoo.com/searchmonkey/smguide/datarss.html * http://suggestions.yahoo.com/?prop=searchmonkey&fid=97199
