The backward step was that some of the DataRSS content in the Yahoo Index appears to have vanished, this broke the examples in the previous post and on the Search Monkey site. I don’t think there is a lot a lowly web site operator like me can do to recover that, but I hope coverage will continue to be at least patchy.  I look forward to the day they just make the RDF available directly, I can see this being much more scalable for them and certainly easier for me.

At the same time I have made a little progress with adding hCalendar support. The level of adoption for hCalendar makes this compelling, though the lack of precision does mean its fundamentally restricted.  I will not, for example, be able to enhance results for pages that mention more than one event, even if one event is clearly (to a human) the primary topic of the page, choosing meaningful graphics is also circuitous.

On the topic of graphics, it is often not possible to depict an event that has not yet occurred. You might choose a graphic for purely aesthetic reasons, use an inconsistent rationale that is difficult to capture, or may abstract away the reasoning into another software module making it unavailable to the UI (as in my case).  This scenario seems to require a specific predicate which I will coin and document as I get around to it. A microformats equivalent is a non-starter as I do not have the inclination to make official representations to standards bodies for work of speculative value (see below).

In total then, the roadmap will be something like this (in order of priority):

1. Basic support for hCalendar (actually tested on upcoming), with simple safeguards for the ambiguous cases.
2. Support for RDFa enhanced pages mentioning multiple events, using foaf:primaryTopic to disambiguate.
3. Support for cases where the event itself can be previewed as a commercial proposition without requiring excess detail in the data, using the new predicate unless I can find one.
4. Support for event ontology actor and factor and associated foaf:depiction triples such that a factor or actor can be reliably depicted in the result.
5. Support for the organiser and logo hCalendar and hCard properties. This is useless to me as the interesting entity for music events is almost never the organiser and never the attendees [ unless you are on a date ], but its feasible so deserves a modicum of attention. I don’t think photo is worth supporting as that would immediately break on conferences.

I’m realistic about the importance of this project for making money as there is no predictable way to ensure large scale adoption of the plugin and the difference in click though rates is also unpredictable. As a result, I’ll be moving this forward primarily as a hackspace project rather than a commercial one, albeit commercially motivated. Doing it on hack evenings is a simple way to box off an amount of time.

Progress will be slow for other reasons, I have to locate implementations of the relevent vocabularies, trawl the Yahoo Index for fully crawled examples and possibly establish some test cases. This will all take time and much of it will be out of my control.