* Transform "media" attribute based on request parameters
*
* @param $media String: current value of the "media" attribute
- * @return String: modified value of the "media" attribute
+ * @return String: modified value of the "media" attribute, or null to skip
+ * this stylesheet
*/
public static function transformCssMedia( $media ) {
global $wgRequest, $wgHandheldForIPhone;
+ // http://www.w3.org/TR/css3-mediaqueries/#syntax
+ $screenMediaQueryRegex = '/^(?:only\s+)?screen\b/i';
+
// Switch in on-screen display for media testing
$switches = array(
'printable' => 'print',
if( $wgRequest->getBool( $switch ) ) {
if( $media == $targetMedia ) {
$media = '';
- } elseif( $media == 'screen' ) {
- return null;
+ } elseif( preg_match( $screenMediaQueryRegex, $media ) === 1 ) {
+ // This regex will not attempt to understand a comma-separated media_query_list
+ //
+ // Example supported values for $media: 'screen', 'only screen', 'screen and (min-width: 982px)' ),
+ // Example NOT supported value for $media: '3d-glasses, screen, print and resolution > 90dpi'
+ //
+ // If it's a print request, we never want any kind of screen styesheets
+ // If it's a handheld request (currently the only other choice with a switch),
+ // we don't want simple 'screen' but we might want screen queries that
+ // have a max-width or something, so we'll pass all others on and let the
+ // client do the query.
+ if( $targetMedia == 'print' || $media == 'screen' ) {
+ return null;
+ }
}
}
}