Now committed is an Atom feed for Blacklight docs. It is advertised for auto-discovery, like the RSS feed is now.
While it could be used simply for feed readers like the RSS feed (and may have a couple extra features for that over the RSS feed), that wasn't why I wrote it -- I wrote it to essentially be a machine-readable response for external software to make an api-like transaction with Blacklight.
To that end, it's got all sorts of goodies in it. It's got a whole bunch of contextual information in the atom:feed, links to next/previous, to the opensearch desc, a bunch of opensearch response elements with contextual info. It's got the actual summary display of the record in atom:summary (whatever you have your helper #render_document_partial(doc, :index) returning).
But the most exciting thing to me is it's support for advertising alternate formats a record may be available in, using the document extension framework. For every format that a document advertises (via it's extensions) it can export in, that documents' atom:entry will have <link rel="alternate"> links to that format.
Additionally, you can supply a &content_format URL parameter, for instance &content_format=marc. And then the marc representation will actually be included in the atom:content element. If it's a non-xml format like :marc, it'll be uu-encoded per the atom spec. If it's an XML format like :marcxml, it'll be right in there. Right now you can just include one embedded format, but in the future I may provide a way to get multiple embedded formats at once.
It'll do this for _whatever_ formats a document registers itself (usually via extensions) as supporting export to, it's not hard-coded at all. This is actually what I wrote the document extension framework for, this atom feed like this, heh.
But do note that it depends on the document having extensions loaded to do this. In an out-of-the-box blacklight installation that is not configured to return the stored marc in "index" (list) view, the Marc extension won't be loaded in index view, and the export formats wont' be registered, and you won't get all this formatty goodness, at least not for Marc. All you need to do to get it for Marc is add your marc display field to the list of index stored fields, and it'll just magically appear.
To see what the formatty goodness gives you in my BL, which is configured to include marc stored fields in index view, check out this URL, and be sure to view source to see the stuff Firefox won't show you in it's atom rendering.
https://blacklight.mse.jhu.edu/demo/catalog.atom?f[format][]=Book&content_format=marc
New Feature
Closed
Major