public List<Animal> SearchAnimals(AnimalDirectoryRequest req)
 {
     var Animals = zooDB.Animals
                     .Where(a => req.AnimalID == null ? true : a.AnimalId == req.AnimalID)
                     .Where(a => req.Name == "" ? true : a.Name == req.Name)
                     .Where(a => req.Type == "" ? true : a.Type == req.Type)
                     .Where(a => req.ZooKeeper == null ? true : a.Zookeeper == req.ZooKeeper);
     return Animals.ToList();
 }
 public ActionResult SearchAnimalDirectory(AnimalDirectoryRequest request)
 {
     AnimalDirectoryModel model = new AnimalDirectoryModel();
     model.Animals = SearchAnimals(request);
     return PartialView("AnimalDirectoryGrid", model);
 }