Exercise Solutions: Edit Model Classes

  1. Create the two handler methods listed below in EventController. We’ll add code to these in a moment, so just put the method outline in place for now.

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    @Controller
@RequestMapping("events")
public class EventController {

   @GetMapping
   public String displayAllEvents(Model model) {
      model.addAttribute("title", "All Events");
      model.addAttribute("events", EventData.getAll());
      return "events/index";
   }

   @GetMapping("create")
   public String displayCreateEventForm(Model model) {
      model.addAttribute("title", "Create Event");
      return "events/create";
   }

   @PostMapping("create")
   public String processCreateEventForm(@ModelAttribute Event newEvent) {
      EventData.add(newEvent);
      return "redirect:";
   }

   @GetMapping("delete")
   public String displayDeleteEventForm(Model model) {
      model.addAttribute("title", "Delete Events");
      model.addAttribute("events", EventData.getAll());
      return "events/delete";
   }

   @PostMapping("delete")
   public String processDeleteEventsForm(@RequestParam(required = false) int[] eventIds) {

      if (eventIds != null) {
            for (int id : eventIds) {
               EventData.remove(id);
            }
      }

      return "redirect:";
   }

   @GetMapping("edit/{eventId}")
   public String displayEditForm(Model model, @PathVariable int eventId){
   }

   @PostMapping("edit")
   public String processEditForm(int eventId, String name, String description) {
   }

}

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  1. Back in the displayEditForm handler, round out the controller method.

    @GetMapping("edit/{eventId}")
public String displayEditForm(Model model, @PathVariable int eventId){
   Event eventToEdit = EventData.getById(eventId);
   model.addAttribute("event", eventToEdit);
   String title = "Edit Event " + eventToEdit.getName() + " (id=" + eventToEdit.getId() + ")";
   model.addAttribute("title", title );
   return "events/edit";
}

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  1. In processEditForm,

    @PostMapping("edit")
public String processEditForm(int eventId, String name, String description) {
   Event eventToEdit = EventData.getById(eventId);
   eventToEdit.setName(name);
   eventToEdit.setDescription(description);
   return "redirect:";
}

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