Update

app/src/main/java/it/chalmers/gamma/adapter/primary/web/GammaErrorController.java

@@ -15,18 +15,19 @@ public class GammaErrorController implements ErrorController {
 
   @GetMapping("/error")
   public ModelAndView handleRuntimeException(
-          @RequestHeader(value = "HX-Request", required = false) boolean htmxRequest,
-          HttpServletResponse response,
-          HttpServletRequest request) {
+      @RequestHeader(value = "HX-Request", required = false) boolean htmxRequest,
+      HttpServletResponse response,
+      HttpServletRequest request) {
     Object statusCodeString = request.getAttribute(RequestDispatcher.ERROR_STATUS_CODE);
     int statusCode = Integer.parseInt(statusCodeString.toString());
 
     System.out.println(statusCode);
 
-    String page = switch(HttpStatus.valueOf(statusCode)) {
-      case NOT_FOUND -> "pages/404";
-      default -> "pages/500";
-    };
+    String page =
+        switch (HttpStatus.valueOf(statusCode)) {
+          case NOT_FOUND -> "pages/404";
+          default -> "pages/error";
+        };
 
     ModelAndView mv = new ModelAndView();
     if (htmxRequest) {

app/src/main/java/it/chalmers/gamma/adapter/primary/web/GroupsController.java

@@ -5,18 +5,22 @@
 
 import it.chalmers.gamma.app.common.PrettyName.PrettyNameValidator;
 import it.chalmers.gamma.app.group.GroupFacade;
+import it.chalmers.gamma.app.group.domain.UnofficialPostName;
 import it.chalmers.gamma.app.post.PostFacade;
 import it.chalmers.gamma.app.supergroup.SuperGroupFacade;
 import it.chalmers.gamma.app.user.UserFacade;
 import it.chalmers.gamma.app.user.domain.Name.NameValidator;
 import jakarta.servlet.http.HttpServletResponse;
 import java.util.*;
 import java.util.stream.Collectors;
+import org.springframework.beans.propertyeditors.StringTrimmerEditor;
+import org.springframework.data.util.Pair;
 import org.springframework.security.authentication.UsernamePasswordAuthenticationToken;
 import org.springframework.security.core.context.SecurityContextHolder;
 import org.springframework.stereotype.Controller;
 import org.springframework.validation.BindingResult;
 import org.springframework.validation.FieldError;
+import org.springframework.web.bind.WebDataBinder;
 import org.springframework.web.bind.annotation.*;
 import org.springframework.web.servlet.ModelAndView;
 
@@ -39,6 +43,11 @@ public GroupsController(
     this.postFacade = postFacade;
   }
 
+  @InitBinder
+  public void initBinder(WebDataBinder binder) {
+    binder.registerCustomEditor(String.class, new StringTrimmerEditor(true));
+  }
+
   @GetMapping("/groups")
   public ModelAndView getGroups(
       @RequestHeader(value = "HX-Request", required = false) boolean htmxRequest) {
@@ -108,14 +117,15 @@ public ModelAndView getGroup(
         "members",
         group.get().groupMembers().stream()
             .map(
-                groupMember ->
-                    new Member(
-                        groupMember.user().nick(),
-                        " - "
-                            + groupMember.post().enName()
-                            + " - "
-                            + Objects.requireNonNullElse(groupMember.unofficialPostName(), ""),
-                        groupMember.user().id()))
+                groupMember -> {
+                  String post = " - " + groupMember.post().enName();
+
+                  if (groupMember.unofficialPostName() != null) {
+                    post += " - " + groupMember.unofficialPostName();
+                  }
+
+                  return new Member(groupMember.user().nick(), post, groupMember.user().id());
+                })
             .toList());
     mv.addObject("random", Math.random());
 
@@ -263,6 +273,8 @@ public void setMembers(List<Member> members) {
     public static final class Member {
       private UUID userId;
       private UUID postId;
+
+      @ValidatedWith(UnofficialPostName.UnofficialPostNameValidator.class)
       private String unofficialPostName;
 
       public Member() {}
@@ -299,12 +311,7 @@ public void setUnofficialPostName(String unofficialPostName) {
     }
   }
 
-  @GetMapping("/groups/{id}/edit")
-  public ModelAndView getGroupEdit(
-      @RequestHeader(value = "HX-Request", required = true) boolean htmxRequest,
-      @PathVariable("id") UUID id,
-      GroupForm form,
-      BindingResult bindingResult) {
+  private ModelAndView createGetGroupEdit(UUID id, GroupForm form, BindingResult bindingResult) {
     Optional<GroupFacade.GroupWithMembersDTO> group = this.groupFacade.getWithMembers(id);
 
     if (group.isEmpty()) {
@@ -321,7 +328,7 @@ public ModelAndView getGroupEdit(
     List<UserFacade.UserDTO> users = this.userFacade.getAll();
     List<PostFacade.PostDTO> posts = this.postFacade.getAll();
 
-    if (form != null) {
+    if (form == null) {
       form =
           new GroupForm(
               group.get().version(),
@@ -362,13 +369,34 @@ public ModelAndView getGroupEdit(
             .map(UserFacade.UserDTO::id)
             .toList());
 
-    if (bindingResult.hasErrors()) {
+    if (bindingResult != null && bindingResult.hasErrors()) {
       mv.addObject(BindingResult.MODEL_KEY_PREFIX + "form", bindingResult);
     }
 
     return mv;
   }
 
+  private void checkForDuplicateEntries(GroupForm form, BindingResult bindingResult) {
+    Set<Pair<UUID, UUID>> uniquePairs = new HashSet<>();
+    for (int i = 0; i < form.getMembers().size(); i++) {
+      GroupForm.Member member = form.getMembers().get(i);
+      Pair<UUID, UUID> pair = Pair.of(member.getUserId(), member.getPostId());
+      if (uniquePairs.contains(pair)) {
+        bindingResult.addError(
+            new FieldError("form", "members[" + i + "]", "Duplicate user/post entry"));
+      } else {
+        uniquePairs.add(pair);
+      }
+    }
+  }
+
+  @GetMapping("/groups/{id}/edit")
+  public ModelAndView getGroupEdit(
+      @RequestHeader(value = "HX-Request", required = true) boolean htmxRequest,
+      @PathVariable("id") UUID id) {
+    return createGetGroupEdit(id, null, null);
+  }
+
   @PutMapping("/groups/{id}")
   public ModelAndView updateGroup(
       @RequestHeader(value = "HX-Request", required = false) boolean htmxRequest,
@@ -379,14 +407,16 @@ public ModelAndView updateGroup(
 
     validateObject(form, bindingResult);
 
+    checkForDuplicateEntries(form, bindingResult);
+
     if (!bindingResult.hasErrors() && this.groupFacade.groupWithNameAlreadyExists(id, form.name)) {
       bindingResult.addError(new FieldError("form", "name", "Group with name already exists"));
     }
 
     if (bindingResult.hasErrors()) {
       response.addHeader("HX-Reswap", "outerHTML");
       response.addHeader("HX-Retarget", "closest <article/>");
-      return this.getGroupEdit(htmxRequest, id, form, bindingResult);
+      return createGetGroupEdit(id, form, bindingResult);
     } else {
       this.groupFacade.update(
           new GroupFacade.UpdateGroup(
@@ -450,8 +480,18 @@ public ModelAndView createGetCreateGroup(
       form = new GroupForm();
     }
 
+    List<UserFacade.UserDTO> users = this.userFacade.getAll();
+    List<PostFacade.PostDTO> posts = this.postFacade.getAll();
+
     mv.addObject("form", form);
     mv.addObject("superGroups", this.superGroupFacade.getAll());
+    mv.addObject(
+        "users",
+        users.stream().collect(Collectors.toMap(UserFacade.UserDTO::id, UserFacade.UserDTO::nick)));
+    mv.addObject(
+        "posts",
+        posts.stream()
+            .collect(Collectors.toMap(PostFacade.PostDTO::id, PostFacade.PostDTO::enName)));
 
     if (bindingResult != null && bindingResult.hasErrors()) {
       mv.addObject(BindingResult.MODEL_KEY_PREFIX + "form", bindingResult);
@@ -474,6 +514,8 @@ public ModelAndView createGroup(
 
     validateObject(form, bindingResult);
 
+    checkForDuplicateEntries(form, bindingResult);
+
     if (bindingResult.hasErrors()) {
       return createGetCreateGroup(htmxRequest, form, bindingResult);
     }

app/src/main/java/it/chalmers/gamma/adapter/primary/web/ThymeleafAdvice.java

@@ -56,5 +56,4 @@ public ModelAndView handleMaxSizeException(HttpServletResponse response) {
   public void handleAccessDeniedException(HttpServletResponse response) throws IOException {
     response.sendRedirect("/");
   }
-
 }

app/src/main/java/it/chalmers/gamma/adapter/primary/web/WebValidationHelper.java

@@ -13,32 +13,61 @@ public class WebValidationHelper {
   public static void validateObject(Object obj, BindingResult bindingResult) {
     Field[] fields = obj.getClass().getDeclaredFields();
     for (Field field : fields) {
-      ValidatedWith validatedWith = field.getAnnotation(ValidatedWith.class);
-      if (validatedWith != null) {
-        field.setAccessible(true);
-        try {
-          Validator<Object> validator =
-              (Validator<Object>) validatedWith.value().getDeclaredConstructor().newInstance();
-          Object fieldValue = field.get(obj);
-          ValidationResult validationResult = validator.validate(fieldValue);
-          if (validationResult instanceof FailedValidation failedValidation) {
-            bindingResult.addError(
-                new FieldError(
-                    "form",
-                    field.getName(),
-                    fieldValue,
-                    true,
-                    null,
-                    null,
-                    failedValidation.message()));
-          }
-        } catch (NoSuchMethodException
-            | InstantiationException
-            | IllegalAccessException
-            | InvocationTargetException e) {
-          throw new RuntimeException(e);
+      validateField(field, "", obj, bindingResult);
+    }
+  }
+
+  private static void validateField(
+      Field field, String prefix, Object obj, BindingResult bindingResult) {
+    field.setAccessible(true);
+    Object fieldValue;
+    try {
+      fieldValue = field.get(obj);
+    } catch (IllegalAccessException e) {
+      throw new RuntimeException(e);
+    }
+
+    ValidatedWith validatedWith = field.getAnnotation(ValidatedWith.class);
+    if (validatedWith != null) {
+      try {
+        Validator<Object> validator =
+            (Validator<Object>) validatedWith.value().getDeclaredConstructor().newInstance();
+        ValidationResult validationResult = validator.validate(fieldValue);
+        if (validationResult instanceof FailedValidation failedValidation) {
+          bindingResult.addError(
+              new FieldError(
+                  "form",
+                  prefix + field.getName(),
+                  fieldValue,
+                  true,
+                  null,
+                  null,
+                  failedValidation.message()));
+        }
+      } catch (NoSuchMethodException
+          | InstantiationException
+          | IllegalAccessException
+          | InvocationTargetException e) {
+        throw new RuntimeException(e);
+      }
+    }
+
+    if (fieldValue instanceof Iterable<?>) {
+      int i = 0;
+      for (Object item : (Iterable<?>) fieldValue) {
+        if (item != null && !item.getClass().isPrimitive() && !(item instanceof String)) {
+          String newPrefix = String.format("%s%s[%d].", prefix, field.getName(), i);
+          validateObject(item, newPrefix, bindingResult);
         }
+        i++;
       }
     }
   }
+
+  private static void validateObject(Object obj, String prefix, BindingResult bindingResult) {
+    Field[] fields = obj.getClass().getDeclaredFields();
+    for (Field field : fields) {
+      validateField(field, prefix, obj, bindingResult);
+    }
+  }
 }

app/src/main/java/it/chalmers/gamma/app/group/GroupFacade.java

@@ -108,8 +108,7 @@ public void setMembers(UUID groupId, List<ShallowMember> newMembers)
               this.postRepository
                   .get(new PostId(shallowMember.postId))
                   .orElseThrow(PostNotFoundRuntimeException::new),
-              new UnofficialPostName(
-                  shallowMember.unofficialPostName == null ? "" : shallowMember.unofficialPostName),
+              new UnofficialPostName(shallowMember.unofficialPostName),
               this.userRepository
                   .get(new UserId(shallowMember.userId))
                   .orElseThrow(UserNotFoundRuntimeException::new)));