Changeset 1404

Timestamp:

03/24/09 16:57:25 (15 years ago)

Author:

epitzer

Message:

New attribute for legitimately empty but storable classes. (#506)

Location:

branches/New Persistence Exploration/Persistence/Persistence/Core

Files:

• Serializer.cs (modified) (1 diff)
• StorableAttribute.cs (modified) (1 diff)

branches/New Persistence Exploration/Persistence/Persistence/Core/Serializer.cs

@@ -132 +132 @@
         }
       }
-      if (nSubComponents == 0) {
+      if (nSubComponents == 0 && ! EmptyStorableClassAttribute.IsEmpyStorable(value)) {
         throw new ApplicationException(
           String.Format(
-            "CustomComposite value of type \"{0}\" contains no subcomponents",
+            "Value of type \"{0}\" has no formatter or decomposer, " +
+            "contains no storable subcomponents, " +
+            "and is not marked as empty storable class.",
             value.GetType().FullName));
       }

branches/New Persistence Exploration/Persistence/Persistence/Core/StorableAttribute.cs

@@ -4 +4 @@
 
 namespace HeuristicLab.Persistence.Core {
+
+  
+  [AttributeUsage(
+    AttributeTargets.Class,
+    AllowMultiple=false,
+    Inherited=false)]
+  public class EmptyStorableClassAttribute : Attribute {
+    private static readonly Dictionary<Type, bool> emptyTypeInfo = new Dictionary<Type, bool>();
+    public static bool IsEmpyStorable(object o) {
+      Type type = o.GetType();
+      if (emptyTypeInfo.ContainsKey(type))
+        return emptyTypeInfo[type];
+      foreach (var attribute in o.GetType().GetCustomAttributes(false)) {
+        EmptyStorableClassAttribute empty = attribute as EmptyStorableClassAttribute;
+        if (empty != null) {
+          emptyTypeInfo.Add(type, true);
+          return true;
+        }
+      }
+      int nFields = 0;
+      foreach ( MemberInfo memberInfo in type.GetMembers(BindingFlags.Instance | BindingFlags.Public | BindingFlags.NonPublic) ) {
+        if (memberInfo.MemberType == MemberTypes.Field ||
+          memberInfo.MemberType == MemberTypes.Property)
+          nFields += 1;
+      }
+      if (nFields == 0) {
+        emptyTypeInfo.Add(type, true);
+        return true;
+      }
+      emptyTypeInfo.Add(type, false);
+      return false;
+    }
+  }
 
   [AttributeUsage(