code.flickr.com

Wildcard Machine Tag URLs

Photo by cackhanded

If you’re not already familiar with machine tags the easiest way to think of them is being like a plain old tag but with a special syntax that allows users to define additional structured data about that tag. In turn the magic space hamsters that run the site have been trained to recognize, index and allow for searches across multiple facets of a given machine tag.

Machine tags have three parts : a namespace which is like a subject or a topic; a predicate which is a like a property of that topic; a value which is … well, a value.

For a more thorough introduction to the subject I’d recommend reading the announcement
we made in the Flickr API discussion group
when machine tags were first added to the site. If you’d like to know even more, after that, there is good collection of links available on del.icio.us.

Which brings us to the part where I tell you that we’ve added the ability to search for machine tagged photos in plain old tag URLs (as well as in tag searches on the Flickr search page) using the facetted query syntax that has always been available in the API. For example :

That’s a trick, really. You’ve always been able to do this since machine tags are just
tags. The New-New means you can be even more granular in what you are looking
for. How about :

The wildcard URL syntax is also available for an individual user’s tags :

Now for the list of caveats and Known-Knowns :