/**
  * Generate JSON for the specified site
  */
 function getJsonList()
 {
     $banners = array();
     // See if we have any preferred campaigns for this language and project
     $campaigns = CentralNoticeDB::getCampaigns($this->project, $this->language, null, 1, 1, $this->location);
     // Quick short circuit to show preferred campaigns
     if ($campaigns) {
         // Pull banners
         $banners = CentralNoticeDB::getCampaignBanners($campaigns);
     }
     // Didn't find any preferred banners so do an old style lookup
     if (!$banners) {
         $banners = CentralNoticeDB::getBannersByTarget($this->project, $this->language, $this->location);
     }
     return FormatJson::encode($banners);
 }