Starts wiring up the back office to the c# bits, updates controllers, mappers, models, property editors to support getting and saving data by language. The content editor now "works" with multi-lingual properties

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

@@ -1,4 +1,6 @@
-using System.Globalization;
+using System.Collections.Generic;
+using System.Globalization;
+using System.Linq;
 using AutoMapper;
 using Umbraco.Core.Models;
 using Umbraco.Web.Models.ContentEditing;
@@ -12,6 +14,38 @@ namespace Umbraco.Web.Models.Mapping
         {
             CreateMap<ILanguage, Language>()
                 .ForMember(l => l.Name, expression => expression.MapFrom(x => x.CultureInfo.DisplayName));
+
+            CreateMap<IEnumerable<ILanguage>, IEnumerable<Language>>()
+                .ConvertUsing<LanguageCollectionTypeConverter>();
+
+        }
+
+        /// <summary>
+        /// Converts a list of <see cref="ILanguage"/> to a list of <see cref="Language"/> and ensures the correct order and defaults are set
+        /// </summary>
+        // ReSharper disable once ClassNeverInstantiated.Local
+        private class LanguageCollectionTypeConverter : ITypeConverter<IEnumerable<ILanguage>, IEnumerable<Language>>
+        {
+            public IEnumerable<Language> Convert(IEnumerable<ILanguage> source, IEnumerable<Language> destination, ResolutionContext context)
+            {
+                var allLanguages = source.OrderBy(x => x.Id).ToList();
+                var langs = new List<Language>(allLanguages.Select(x => context.Mapper.Map<ILanguage, Language>(x, null, context)));
+
+                //if there's only one language, by default it is the default
+                if (langs.Count == 1)
+                {
+                    langs[0].IsDefaultVariantLanguage = true;
+                    langs[0].Mandatory = true;
+                }
+                else if (allLanguages.All(x => !x.IsDefaultVariantLanguage))
+                {
+                    //if no language has the default flag, then the defaul language is the one with the lowest id
+                    langs[0].IsDefaultVariantLanguage = true;
+                    langs[0].Mandatory = true;
+                }
+
+                return langs.OrderBy(x => x.Name);
+            }
         }
     }
 }