Added EncodingResolverAttribute

evicertia · Apr 15, 2016 · f68e734 · f68e734
1 parent 653a0dc
commit f68e734
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Showing 3 changed files with 40 additions and 4 deletions.
diff --git a/HermaFx.Foundation/HermaFx.Foundation.csproj b/HermaFx.Foundation/HermaFx.Foundation.csproj
@@ -99,6 +99,7 @@
     <Compile Include="RuntimeExtensions\SysDate.cs" />
     <Compile Include="RuntimeExtensions\TypeExtensions.cs" />
     <Compile Include="Text\EncodingConverter.cs" />
+    <Compile Include="Text\EncodingResolverAttribute.cs" />
     <Compile Include="Text\IEncodingResolver.cs" />
     <Compile Include="X509Certificates\CertificateString.cs" />
     <Compile Include="ServiceLocation\ServiceLocator.cs" />

diff --git a/HermaFx.Foundation/Text/EncodingConverter.cs b/HermaFx.Foundation/Text/EncodingConverter.cs
@@ -24,9 +24,17 @@ public EncodingConverter()
 
 		}
 
-		private Encoding GetEncoding(string name)
+		private IEncodingResolver GetResolver(ITypeDescriptorContext context)
 		{
-			if (_resolver != null && !AllEncodings.Any(x => x == name.ToLowerInvariant()))
+			var attr = context.PropertyDescriptor.Attributes.OfType<EncodingResolverAttribute>().SingleOrDefault();
+			return attr != null ? attr.GetResolver() : _resolver;
+		}
+
+		private Encoding GetEncoding(ITypeDescriptorContext context, string name)
+		{
+			var resolver = GetResolver(context);
+
+			if (resolver != null && !AllEncodings.Any(x => x == name.ToLowerInvariant()))
 				return _resolver.GetEncoding(name);
 
 			return Encoding.GetEncoding(name);
@@ -51,7 +59,7 @@ public override object ConvertFrom(ITypeDescriptorContext context, CultureInfo c
 			Guard.IsNotNull(value, nameof(value));
 			Guard.Against<NotSupportedException>(!CanConvertFrom(context, value.GetType()), "Cannot convert from value: {0}", value);
 
-			return value is Encoding ? value : GetEncoding(value as string);
+			return value is Encoding ? value : GetEncoding(context, value as string);
 		}
 
 		public override object ConvertTo(ITypeDescriptorContext context, CultureInfo culture, object value, Type destinationType)
@@ -67,7 +75,7 @@ public override object ConvertTo(ITypeDescriptorContext context, CultureInfo cul
 			var name = value as string;
 			if (name != null)
 			{
-				return destinationType == typeof(string) ? value : GetEncoding(name);
+				return destinationType == typeof(string) ? value : GetEncoding(context, name);
 			}
 
 			return base.ConvertTo(context, culture, value, destinationType);

diff --git a/HermaFx.Foundation/Text/EncodingResolverAttribute.cs b/HermaFx.Foundation/Text/EncodingResolverAttribute.cs
@@ -0,0 +1,27 @@
+using System;
+
+namespace HermaFx.Text
+{
+	[AttributeUsage(AttributeTargets.Property, Inherited = true, AllowMultiple = false)]
+	sealed class EncodingResolverAttribute : Attribute
+	{
+		readonly Type _resolver;
+
+		public IEncodingResolver GetResolver()
+		{
+			return (IEncodingResolver)Activator.CreateInstance(_resolver);
+		}
+
+		// This is a positional argument
+		public EncodingResolverAttribute(Type resolver)
+		{
+			Guard.IsNotNull(resolver, nameof(resolver));
+			Guard.Against<ArgumentOutOfRangeException>(
+				typeof(IEncodingResolver).IsAssignableFrom(resolver), 
+				"Type {0} does not implement {1}", resolver.FullName, typeof(IEncodingResolver).FullName
+			);
+
+			_resolver = resolver;
+		}
+	}
+}