check for existing file content when creating/saving new template

src/Umbraco.Core/Services/FileService.cs

@@ -291,6 +291,14 @@ namespace Umbraco.Core.Services
                 {"ContentTypeAlias", contentTypeAlias},
             };
 
+            // check that the template hasn't been created on disk before creating the content type
+            // if it exists, set the new template content to the existing file content
+            string content = GetViewContent(contentTypeAlias);
+            if (content.IsNullOrWhiteSpace() == false)
+            {
+                template.Content = content;
+            }
+
             using (var uow = UowProvider.GetUnitOfWork())
             {
                 var saveEventArgs = new SaveEventArgs<ITemplate>(template, true, evtMsgs, additionalData);
@@ -1045,6 +1053,19 @@ namespace Umbraco.Core.Services
                 : Attempt<string>.Fail();
         }
 
+        internal Attempt<string> TryGetViewPath(string fileName)
+        {
+            if (fileName.EndsWith(".cshtml") == false)
+            {
+                fileName += ".cshtml";
+            }
+
+            string viewPath = IOHelper.MapPath(SystemDirectories.MvcViews + "/" + fileName);
+            return System.IO.File.Exists(viewPath)
+                ? Attempt<string>.Succeed(viewPath)
+                : Attempt<string>.Fail();
+        }
+
         private IPartialViewRepository GetPartialViewRepository(PartialViewType partialViewType, IUnitOfWork uow)
         {
             switch (partialViewType)
@@ -1076,6 +1097,23 @@ namespace Umbraco.Core.Services
             return GetPartialViewMacroSnippetContent(snippetName, PartialViewType.PartialViewMacro);
         }
 
+        public string GetViewContent(string filename)
+        {
+            if (filename.IsNullOrWhiteSpace())
+                throw new ArgumentNullException(nameof(filename));
+
+            Attempt<string> viewAttempt = TryGetViewPath(filename);
+            if (viewAttempt.Success == false)
+            {
+                return string.Empty;
+            }
+
+            using (var view = new StreamReader(System.IO.File.OpenRead(viewAttempt.Result)))
+            {
+                return view.ReadToEnd().Trim();
+            }
+        }
+
         private string GetPartialViewMacroSnippetContent(string snippetName, PartialViewType partialViewType)
         {
             if (snippetName.IsNullOrWhiteSpace())
@@ -1265,4 +1303,4 @@ namespace Umbraco.Core.Services
 
         #endregion
     }
-}
+}

src/Umbraco.Core/Services/IFileService.cs

@@ -427,5 +427,12 @@ namespace Umbraco.Core.Services
         /// <param name="filepath">The filesystem path to the partial view.</param>
         /// <returns>The size of the partial view.</returns>
         long GetPartialViewFileSize(string filepath);
+
+        /// <summary>
+        /// Gets the content of a view.
+        /// </summary>
+        /// <param name="filename">The name of the view.</param>
+        /// <returns></returns>
+        string GetViewContent(string filename);
     }
-}
+}

src/Umbraco.Web/Editors/TemplateController.cs

@@ -1,9 +1,12 @@
 using System.Collections.Generic;
+using System.IO;
 using System.Linq;
 using System.Net;
 using System.Net.Http;
+using System.Web;
 using System.Web.Http;
 using AutoMapper;
+using Umbraco.Core;
 using Umbraco.Core.IO;
 using Umbraco.Core.Models;
 using Umbraco.Core.Services;
@@ -178,6 +181,14 @@ namespace Umbraco.Web.Editors
             else
             {
                 //create
+
+                // file might already be on disk, if so grab the content to avoid overwriting
+                string content = Services.FileService.GetViewContent(display.Alias);
+                if (string.IsNullOrEmpty(content) == false)
+                {
+                    display.Content = content;
+                }
+
                 ITemplate master = null;
                 if (string.IsNullOrEmpty(display.MasterTemplateAlias) == false)
                 {