fix: handle invalid form message on login and signup form librarian

users/templates/librarians/login.html

@@ -17,7 +17,6 @@
     >
       Login
     </button>
-    <p>{{ error_message }}</p>
     <div class="d-flex flex-column align-items-center">
       <p class="my-2">
         Don't have an account? <a href="/users/auth/sign-up">Sign Up</a>

users/views.py

@@ -151,15 +151,13 @@ class LibrarianLoginView(LoginView):
 
     def post(self, request, *args, **kwargs):
         form = self.get_form()
-        context = self.get_context_data()
 
         if form.is_valid():
             username = form.data.get("username")
             user = User.objects.get(username=username)
 
             if not user.is_staff:
-                context["error_message"] = "Access Denied, account is not staff"
-
+                form.add_error(field=None, error="Access Denied, account is not staff")
                 return self.form_invalid(form)
 
             librarian = Librarian.objects.get(user=user)
@@ -192,7 +190,6 @@ class LibrarianSignUpView(generic.FormView):
         form = self.get_form()
 
         if form.is_valid:
-            context = self.get_context_data()
             username = form.data.get("username")
             email = form.data.get("email")
             password1 = form.data.get("password1")
@@ -206,6 +203,10 @@ class LibrarianSignUpView(generic.FormView):
             if is_email.exists():
                 return self.form_invalid(form)
 
+            is_username = User.objects.filter(username=username)
+            if is_username.exists():
+                return self.form_invalid(form)
+
             user = User.objects.create_user(
                 username=username, email=email, is_staff=True
             )