code: private function isCmsActive()
      {
          $melisCms  = 'MelisCms';
          $moduleSvc = $this->getServiceLocator()->get('ModulesService');
          $modules   = $moduleSvc->getActiveModules();
          
          if(in_array($melisCms, $modules)) {
              return true;
          }
          
          return false;
      }
docs: Checking if MelisCms modul is activated
  
  @return boolean