Updated some of the property editor API to ensure that when formatting data for persistence we have access to the pre-values as well since these might need to be used to format the persisted data. Completed the new property editor: Multiple text box and it is saving the data in a backwards compatible format. Changed the internal AsDictionary method of the pre value collection to be a public method called FormatAsDictionary.

src/Umbraco.Web/Models/Mapping/ContentModelMapper.cs

@@ -9,13 +9,13 @@ using Umbraco.Core;
 using Umbraco.Core.Models;
 using Umbraco.Core.Models.Mapping;
 using Umbraco.Core.PropertyEditors;
+using Umbraco.Core.Services;
 using Umbraco.Web.Models.ContentEditing;
 using umbraco;
 using Umbraco.Web.Routing;
 
 namespace Umbraco.Web.Models.Mapping
 {
-
     /// <summary>
     /// Declares how model mappings for content
     /// </summary>
@@ -73,7 +73,7 @@ namespace Umbraco.Web.Models.Mapping
 
             //FROM IContent TO ContentItemDto<IContent>
             config.CreateMap<IContent, ContentItemDto<IContent>>()
-                  .ForMember(
+                .ForMember(
                       dto => dto.Owner,
                       expression => expression.ResolveUsing<OwnerResolver<IContent>>());