Jeroens blog

Result format aliases for SMW

16 Oct 2009 @ 6:09 PM

Today I’ve wrote a small change to Semantic MediaWiki that adds aliasing supports to it’s result formats. I’ve been working (mainly theorizing) on this for quite a while, and came up with some rather complex solutions, that where not feasible since they required PHP 5.3. The implementation I ended up with is ridiculously easy, and works with an $smwgResultAliases array. This array holds result formats as the keys, and the aliases as (array) value. A simple example of adding aliases using this array is:

$smwgResultAliases['googlemaps'] = array(‘googlemap’, ‘gmap’, ‘google’);

Here googlemap, gmap and google will do the same as googlemaps, which is the actual result format. To hold into account these aliases, I only needed to add some simple code to the getResultFormat function in SMWQueryProcessor. This is the code:

static protected function getResultFormat($params) {
global $smwgResultAliases;

$format = 'auto';
if (array_key_exists('format', $params)) {
$format = strtolower(trim($params['format']));
global $smwgResultFormats;

if ( !array_key_exists($format, $smwgResultFormats) ) {

foreach($smwgResultAliases as $mainFormat => $aliases) {
if (in_array($format, $aliases)) {
$format = $mainFormat;
$isAlias = true;
continue;
}
}

if (! $isAlias) $format = 'auto'; // If it is an unknown format, defaults to list/table again
}
}
return $format;
}

This implementation is fully working with Semantic Maps, and has fixed an issue this extension had with the display of it’s result formats on the special:ask page (see screenshot).