MediaWiki:Common.js

$( '.transclusion-container .additional' ).each(function() {

   var $elem = $(this);
   var $toggle = $('<a href="#" class="bs-icon-arrow-down"></a>');
   $toggle.on( 'click', function( e ) {
       $elem.toggleClass( 'show' );
       e.defaultPrevented = true;
       return false;
   });
   $toggle.insertBefore( $elem );

});

$( '.languageselector' ).each(function() {

   var languages = [ 'de', 'en', 'cz', 'pl', 'hu' ];
   var $selector = $('<select>');
   for( var i = 0; i < languages.length; i++ ) {
       var language = languages[i];
       var $option = $('<option>');
       $option.html( language  );
       $option.val( language  );

       $selector.append( $option );
   }
   $(this).append( $selector );

});