lazy load 4

gistfile1.cs

[Serializable]
public sealed class LazyLoadAttribute : LocationInterceptionAspect
{
    private Type _type;

    public override bool CompileTimeValidate(PostSharp.Reflection.LocationInfo locationInfo)
    {
        if(!locationInfo.LocationType.IsInterface)
        {
            Message.Write(SeverityType.Error, "001", "LazyLoad can only be used on Interfaces in {0}.{1}", locationInfo.DeclaringType, locationInfo.Name);
            return false;
        }

        _type = DependencyMap.GetConcreteType(locationInfo.LocationType);
        if(_type == null)
        {
            Message.Write(SeverityType.Error, "002", "A concrete type was not found for {0}.{1}", locationInfo.DeclaringType, locationInfo.Name);
            return false;
        }
        return true;
    }

    public override void OnGetValue(LocationInterceptionArgs args)
    {
        args.ProceedGetValue();
        if (args.Value == null)
        {
            args.SetNewValue(Activator.CreateInstance(_type));
            args.ProceedGetValue();
        }
    }
}