[SMW-devel] RFC: SMW query API

[Jeroen De D. <jer...@gm...>]

Hey all,

Recently there have been several questions about querying SMW using
MediaWiki API modules. The SMWAskAPI [0] extension is a nice proof of
concept for the usefullness of this, and also indicates there is an actual
demand for it. After discussion with several people, I decided to implement
such functionality in SMW itself, and currently have an alpha version. The
parameters it takes are slightly different from the SMWAskAPI extension, and
the output is not the same.

To try this out, get the latest version of SMW from SVN.

There are 2 API modules that differ in how you specify the query, but have
identical output of the query results.

The first one is "ask", which supports one parameter, query, which takes the
same string you'd feed into an #ask tag, but urlencoded. Example:
api.php?action=ask&query=[[Modification date::%2B]]|%3FModification
date|sort%3DModification date|order%3Ddesc&format=jsonfm

The second one is "askargs", which aims to take arguments in unserialized
form, so with as little ask-specific syntax as possible. It supports 3
arguments:
* conditions: The query conditions, ie the requirements for a subject to be
included
* printeouts: The query printeouts, ie the properties to show per subject
* parameters: The query parameters, ie all non-condition and non-printeout
arguments
Example:
api.php?action=askargs&conditions=Modification
date::%2B&printeouts=Modification date&parameters=|sort%3DModification
date|order%3Ddesc&format=jsonfm

Feedback is very welcome, so the output structure of the API can be fixed in
the next release, after which external developers will be able to actually
rely on it :)

[0]
https://secure.wikimedia.org/wikipedia/mediawiki/wiki/Extension:SMWAskAPI

Cheers

--
Jeroen De Dauw
http://www.bn2vs.com
Don't panic. Don't be evil.
--