Add success message for create event

src/main/java/polish_community_group_11/polish_community/event/controllers/EventController.java

@@ -10,6 +10,7 @@ import org.springframework.web.bind.annotation.PostMapping;
 import org.springframework.web.servlet.ModelAndView;
 import org.springframework.stereotype.Controller;
 import org.springframework.web.bind.annotation.GetMapping;
+import org.springframework.web.servlet.mvc.support.RedirectAttributes;
 import polish_community_group_11.polish_community.event.models.viewmodel.EventForm;
 import org.springframework.web.bind.annotation.*;
 import polish_community_group_11.polish_community.event.models.Event;
@@ -83,7 +84,7 @@ public class EventController {
     @PostMapping("event/add")
     public ModelAndView addEvent(@Valid @ModelAttribute("event") EventForm event,
                                  BindingResult bindingResult, Model model,
-                                 Principal principal) throws SQLException {
+                                 Principal principal, RedirectAttributes redirectAttributes) throws SQLException {
         ModelAndView modelAndView = new ModelAndView("event/add-event");
         if(bindingResult.hasErrors()) {
             modelAndView.addObject(model.asMap());
@@ -97,6 +98,7 @@ public class EventController {
                 throw new NullPointerException("New event is empty or null");
             }
             eventService.addNewEvent(event.processEventForm(),principal.getName());
+            redirectAttributes.addFlashAttribute("successMessage", "Event created successfully!");
             modelAndView.setViewName("redirect:/event");
         }
         return modelAndView;

src/main/resources/templates/event/event.html

@@ -36,5 +36,8 @@
           </div>
         </div>
         <script src="/js/event/event.js"></script>
+        <script th:if="${successMessage}">
+            alert("Event created successfully");
+        </script>
     </section>
 </html>