/**
* this function loads the thumbnail image for the challenge identity
*/
public function actionIcon()
{
$challenge = get_entity($this->url_vars[1]);
$size = $this->url_vars[2];
$image_name = 'contest/' . $challenge->guid . '/icon' . ($size ? $size : 'small') . '.jpg';
$content = IzapBase::getFile(array('source' => $image_name, 'owner_guid' => $challenge->owner_guid));
if (empty($content)) {
$content = file_get_contents(elgg_get_plugins_path() . GLOBAL_IZAP_ELGG_BRIDGE . '/_graphics/no-image-' . $size . '.jpg');
}
$header_array = array();
$header_array['content_type'] = 'image/jpeg';
$header_array['file_name'] = elgg_get_friendly_title($challenge->title);
IzapBase::cacheHeaders($header_array);
echo $content;
}