AttributeMap.cs :  » Persistence-Frameworks » Persist.NET » Persist » Maps » C# / CSharp Open Source

// Persist library : Persistence layer
// Copyright (C) 2003 Vincent Daron
// 
// This library is free software; you can redistribute it and/or
// modify it under the terms of the GNU Lesser General Public
// License as published by the Free Software Foundation; either
// version 2.1 of the License, or (at your option) any later version.
// 
// This library 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
// Lesser General Public License for more details.
// 
// You should have received a copy of the GNU Lesser General Public
// License along with this library; if not, write to the Free Software
// Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA  02111-1307  USA

using System;
using System.Data;
using System.Reflection;
using System.Collections;

using Persist.Attributes;

namespace Persist.Maps{
   /// <summary>
   /// Map a Database Column on a Class Attribute
   /// </summary>
  public class AttributeMap
  {
      private ColumnMap theColumnMap;
      private AttributeMap theReference;
      private System.Reflection.PropertyInfo thePropertyInfo;
      private System.Reflection.FieldInfo theFieldInfo;

      private string theName;
      private bool isProxy;
      private bool isOptimistCheckAttribute;

      /// <summary>
      /// Constructor
      /// </summary>
      /// <param name="name">the Attribute Map Name</param>
      public AttributeMap(string name)
    {
         theName = name;
    }
      /// <summary>
      /// Specified if this attribute is part of the Proxy object
      /// </summary>
      public bool IsProxy
      {
         get{return isProxy;}
         set{isProxy = value;}
      }      
      /// <summary>
      /// Specified if this is the OptimistLock Attribute
      /// </summary>
      public bool IsOptimistCheckAttribute
      {
         get{return isOptimistCheckAttribute;}
         set{isOptimistCheckAttribute = value;}
      }      
      /// <summary>
      /// The name of the Attribute to map
      /// </summary>
      public string Name
      {
         get{return theName;}
         set{theName = value;}
      }
      /// <summary>
      /// The Corresponding ColumnMap
      /// </summary>
      public ColumnMap ColumnMap
      {
         get
         {
            return theColumnMap;
         }
         set
         {
            theColumnMap = value;
         }
      }

      /// <summary>
      /// Unused for now (TODO :) )
      /// </summary>
      public AttributeMap Reference
      {
         get
         {
            return theReference;
         }
         set
         {
            theReference = value;
         }
      }
      /// <summary>
      /// Initialize the AttributeMap
      /// </summary>
      /// <param name="configuration">the Configuration</param>
      internal void Init(Config.Configuration configuration)
      {
         if(theColumnMap != null)
         {
            theColumnMap.Init(configuration);
         }
      }


      /// <summary>
      /// Find by Reflection, the Attribute to Map
      /// The search order is the following :
      ///  1) Look for a corresponding AttributeNameAttribute
      ///  2) Look for an Attribute with the corresponding name
      /// </summary>
      /// <param name="mapObjectType">the Type of object to look for attribute mapping</param>
      internal void InitAccessors(Type mapObjectType)
      {
         theFieldInfo = null;

         foreach(FieldInfo fieldInfo in mapObjectType.GetFields(BindingFlags.NonPublic|BindingFlags.Public|BindingFlags.GetField|BindingFlags.Instance))
         {
            foreach(AttributeNameAttribute attributeName in fieldInfo.GetCustomAttributes(typeof(AttributeNameAttribute),true))
            {
               if(attributeName.Name == Name)
               {
                  theFieldInfo = fieldInfo;
                  break;
               }
            }
            if(theFieldInfo != null)
            {
               break;
            }
         }

         if(theFieldInfo == null)
         {
            theFieldInfo = mapObjectType.GetField(Name,BindingFlags.NonPublic|BindingFlags.Public|BindingFlags.GetField|BindingFlags.Instance);
            if(theFieldInfo == null)
            {
               thePropertyInfo = mapObjectType.GetProperty(Name,BindingFlags.NonPublic|BindingFlags.Public|BindingFlags.GetProperty|BindingFlags.Instance);
               if((thePropertyInfo == null)||(!thePropertyInfo.CanRead)||(!thePropertyInfo.CanWrite))
               {
                  throw new Exception("Cannot find Field or Property "+Name+" in type "+mapObjectType);
               }
            }
         }
      }

      /// <summary>
      /// Get the value of the attribute for the specified object
      /// </summary>
      /// <param name="source">the object</param>
      /// <returns>the Attribute value</returns>
      public object GetValue(object source)
      {
         object result;
         if(theFieldInfo != null)
         {
            result =  theFieldInfo.GetValue(source);
         }
         else
         {
            result = thePropertyInfo.GetValue(source,null);
         }
         return result;
      }
      /// <summary>
      /// Set the Attribute value of the object
      /// </summary>
      /// <param name="target">the object to modify</param>
      /// <param name="value">the attribute value</param>
      public void SetValue(object target,object value)
      {
         if(theFieldInfo != null)
         {
            theFieldInfo.SetValue(target,value);
         }
         else
         {
            thePropertyInfo.SetValue(target,value,null);
         }
      }
  }
}