Adding in server side validation - but need to clarify that this is the 'right' way to do it that wires up correctly/magically back to the UI components

src/Umbraco.Web/Editors/TemplateController.cs

@@ -6,8 +6,10 @@ using System.Web.Http;
 using AutoMapper;
 using Umbraco.Core.IO;
 using Umbraco.Core.Models;
+using Umbraco.Core.Services;
 using Umbraco.Web.Models.ContentEditing;
 using Umbraco.Web.Mvc;
+using Umbraco.Web.WebApi;
 using Umbraco.Web.WebApi.Filters;
 using Constants = Umbraco.Core.Constants;
 
@@ -86,6 +88,17 @@ namespace Umbraco.Web.Editors
         /// <returns></returns>
         public TemplateDisplay PostSave(TemplateDisplay display)
         {
+
+            //Checking the submitted is valid with the Required attributes decorated on the ViewModel
+            if (ModelState.IsValid == false)
+            {
+                //Unsure of the standard or set way to do this?!
+                //throw new HttpResponseException(Request.CreateNotificationValidationErrorResponse("MISSING NAME"));
+
+                throw new HttpResponseException(Request.CreateErrorResponse(HttpStatusCode.BadRequest, ModelState));
+            }
+
+
             if (display.Id > 0)
             {
                 // update

src/Umbraco.Web/Models/ContentEditing/TemplateDisplay.cs

@@ -1,21 +1,26 @@
 using System;
 using System.Collections.Generic;
+using System.ComponentModel.DataAnnotations;
 using System.Linq;
 using System.Runtime.Serialization;
 using System.Text;
 using System.Threading.Tasks;
+using Umbraco.Core.Models.Validation;
 
 namespace Umbraco.Web.Models.ContentEditing
 {
     [DataContract(Name = "template", Namespace = "")]
     public class TemplateDisplay
     {
+
         [DataMember(Name = "id")]
         public int Id { get; set; }
 
+        [Required]
         [DataMember(Name = "name")]
         public string Name { get; set; }
 
+        [RequiredForPersistence]
         [DataMember(Name = "alias")]
         public string Alias { get; set; }