in assets/js/mod/select_logic.js [8:23]
function selectPlatform($root) {
var
$platformSelect = $root,
$artifactSelect = $platformSelect.parent().children('.dl-artifact-select'),
$extraLinks = $platformSelect.parent().children('.extra-links-group'),
firstItemVal;
$artifactSelect.children().show();
$artifactSelect.children(':not(.platform_'+$platformSelect.val()+')').hide();
firstItemVal = $artifactSelect.children('.platform_'+$platformSelect.val()).first().val();
$artifactSelect.val(firstItemVal);
$extraLinks.children().show();
$extraLinks.children(':not(.extra_'+$platformSelect.val()+')').hide();
selectExtras($extraLinks,firstItemVal);
}