Adding router.php in Joomla component breaks site

Adding router.php in Joomla component breaks site

I'm trying to add routing for a custom component I made and I followed the
docs on how to do this. But when I uploaded the router.php file to the
component, it rendered the site blank. Not sure if I'm missing anything.
component\router.php
function componentBuildRoute( &$query )
{
$segments = array();
if(isset($query['view'])) {
$segments[] = $query['view'];
unset($query['view']);
}
if(isset($query['cat'])) {
$segments[] = $query['cat'];
unset($query['cat']);
}
if(isset($query['itemid'])) {
$segments[] = $query['itemid'];
unset($query['itemid']);
}
if(isset($query['color'])) {
$segments[] = $query['color'];
unset($query['color']);
}
return $segments;
}
function componentParseRoute($segments) {
$vars = array();
switch($segments[0])
{
case 'listing':
$vars['view'] = $this->chooseView($segments[1]);
break;
case 'item':
$vars['id'] = $segments[1].'-'.$segments[2];
break;
}
return $vars;
}
private function chooseView($cat) {
switch($cat) {
case '1':
$cat = 'trousers';
break;
case '2':
$cat = 'jackets';
break;
}
return $cat;
}