Integrating some localizer support for encoding and pluralization

Formatter internally encodes information passed as object[] args as appropriate
Resulting LocalizedString marked as html-encoded to prevent double-encoding
Extension method for <%:T.Plural("1 thing", "{0} things", n, ...)%>

--HG--
branch : dev

src/Orchard/Localization/LocalizedString.cs

@@ -1,7 +1,8 @@
 using System;
+using System.Web;
 
 namespace Orchard.Localization {
-    public class LocalizedString : MarshalByRefObject {
+    public class LocalizedString : MarshalByRefObject, IHtmlString {
         private readonly string _localized;
 
         public LocalizedString(string localized) {
@@ -20,6 +21,10 @@ namespace Orchard.Localization {
             return _localized;
         }
 
+        string IHtmlString.ToHtmlString() {
+            return _localized;
+        }
+
         public override int GetHashCode() {
             var hashCode = 0;
             if (_localized != null)
@@ -31,8 +36,9 @@ namespace Orchard.Localization {
             if (obj == null || obj.GetType() != GetType())
                 return false;
 
-            var that = (LocalizedString) obj;
+            var that = (LocalizedString)obj;
             return string.Equals(_localized, that._localized);
         }
+
     }
 }

src/Orchard/Localization/Localizer.cs

@@ -1,3 +1,11 @@
+using System.Linq;
+
 namespace Orchard.Localization {
     public delegate LocalizedString Localizer(string text, params object[] args);
-}
+
+    public static class LocalizerExtensions {
+        public static LocalizedString Plural(this Localizer T, string textSingular, string textPlural, int count, params object[] args) {
+            return T(count == 1 ? textSingular : textPlural, new object[] { count }.Concat(args).ToArray());
+        }
+    }
+}

src/Orchard/Localization/Text.cs

@@ -1,3 +1,6 @@
+using System;
+using System.Globalization;
+using System.Linq;
 using System.Web;
 using Orchard.Localization.Services;
 using Orchard.Logging;
@@ -23,9 +26,25 @@ namespace Orchard.Localization {
             string currentCulture = _cultureManager.GetCurrentCulture(HttpContext.Current);
             var localizedFormat = _resourceManager.GetLocalizedString(_scope, textHint, currentCulture);
 
-            return args.Length < 1
-                ? new LocalizedString(localizedFormat)
-                : new LocalizedString(string.Format(localizedFormat, args));
+            return args.Length == 0 
+                ? new LocalizedString(localizedFormat) 
+                : string.Format(GetFormatProvider(currentCulture), localizedFormat, args.Select(Encode).ToArray());
+        }
+
+        private static IFormatProvider GetFormatProvider(string currentCulture) {
+            try {
+                return CultureInfo.GetCultureInfoByIetfLanguageTag(currentCulture);
+            }
+            catch {
+                return null;
+            }
+        }
+
+        static object Encode(object arg) {
+            if (arg is IFormattable || arg is IHtmlString) {
+                return arg;
+            }
+            return HttpUtility.HtmlEncode(arg);
         }
     }
 }