source: branches/PersistenceOverhaul/HeuristicLab.Persistence/4.0/Transformers/EmptyTypeTransformer.cs @ 13326

#region License Information
/* HeuristicLab
 * Copyright (C) 2002-2012 Heuristic and Evolutionary Algorithms Laboratory (HEAL)
 *
 * This file is part of HeuristicLab.
 *
 * HeuristicLab is free software: you can redistribute it and/or modify
 * it under the terms of the GNU General Public License as published by
 * the Free Software Foundation, either version 3 of the License, or
 * (at your option) any later version.
 *
 * HeuristicLab is distributed in the hope that it will be useful,
 * but WITHOUT ANY WARRANTY; without even the implied warranty of
 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
 * GNU General Public License for more details.
 *
 * You should have received a copy of the GNU General Public License
 * along with HeuristicLab. If not, see <http://www.gnu.org/licenses/>.
 */
#endregion

using System;
using System.Reflection;
using HeuristicLab.Persistence.Data;

namespace HeuristicLab.Persistence {
  [Transformer("A2A2F675-012B-4D50-93A5-B8E728D9809C", 999)]
  internal sealed class EmptyTypeTransformer : TransformerBase {
    public override bool CanTransformType(Type type) {
      while (type != null) {
        if (type.IsArray) return false;  // arrays are no empty types but contain no fields
        var fields = type.GetFields(BindingFlags.Instance | BindingFlags.Public | BindingFlags.NonPublic | BindingFlags.DeclaredOnly);
        if (fields.Length != 0) return false;
        type = type.BaseType;
      }
      return true;
    }
    public override PersistenceData ToData(object o, PersistenceMapper mapper) {
      var type = o.GetType();
      var data = new ValueData<ushort>(Id);
      mapper.Cache(o, data);
      data.Value = mapper.GetTypeId(type);
      return data;
    }

    public override object ToObject(PersistenceData data, PersistenceMapper mapper) {
      var primitive = (ValueData<ushort>)data;
      var o = Activator.CreateInstance(mapper.GetType(primitive.Value));
      mapper.Cache(data, o);
      return o;
    }
  }
}