Rename namespace from Umbraco.Core.Resolving to Umbraco.Core.ObjectResolution

src/Umbraco.Core/ObjectResolution/SingleObjectResolverBase.cs

@@ -0,0 +1,60 @@
+using System;
+
+namespace Umbraco.Core.ObjectResolution
+{
+	/// <summary>
+	/// A Resolver to return and set a Single registered object.
+	/// </summary>
+	/// <typeparam name="TResolved"></typeparam>
+	/// <typeparam name="TResolver"> </typeparam>
+	/// <remarks>
+	/// Used for 'singly' registered objects. An example is like the MVC Controller Factory, only one exists application wide and it can
+	/// be get/set.
+	/// </remarks>
+	internal abstract class SingleObjectResolverBase<TResolver, TResolved> : ResolverBase<TResolver>
+		where TResolved : class
+		where TResolver : class
+	{
+		TResolved _resolved;
+		readonly bool _canBeNull;
+
+		protected SingleObjectResolverBase()
+			: this(false)
+		{ }
+
+		protected SingleObjectResolverBase(TResolved value)
+			: this(false)
+		{
+			_resolved = value;
+		}
+
+		protected SingleObjectResolverBase(bool canBeNull)
+		{
+			_canBeNull = canBeNull;
+		}
+
+		protected SingleObjectResolverBase(TResolved value, bool canBeNull)
+		{
+			_resolved = value;
+			_canBeNull = canBeNull;
+		}
+
+		/// <summary>
+		/// Gets/sets the value of the object
+		/// </summary>
+		protected TResolved Value
+		{
+			get
+			{
+				return _resolved;
+			}
+
+			set
+			{
+				if (!_canBeNull && value == null)
+					throw new ArgumentNullException("value");
+				_resolved = value;
+			}
+		}
+	}
+}