①Info.plistの中に
 <key>NSPrincipalClass</key>
 <string>AUDiffCustom</string>

②protocolの定義
@protocol AUDiffCustomMgr
- (int)Update_BeforeUpdate:(BOOL*)isRestart;
- (int)Update_AfterUpdate:(BOOL*)isRestart;

③NSBundleのロード
-(void)loadAUDiffCustomBundle
{
 NSBundle* bundle;
 Class principalClass;
 id instance;
 NSString* bundlePath = [[folderPath stringByAppendingPathComponent:@"CUSTOM"] stringByAppendingPathComponent:fileName];
 bundle = [NSBundle bundleWithPath:bundlePath];
 if ( [bundle load] == NO ) { 
  return;
 }
 
 principalClass = [bundle principalClass];

 if( !(principalClass && [principalClass conformsToProtocol:@protocol(AUDiffCustomMgr)]) )
 {
  return ;
 }
 else
 {
  instance = [[principalClass alloc] init];

  if ( [functionName isEqualToString:@"Update_BeforeUpdate"] )
  {
   result = [instance Update_BeforeUpdate:&isRestart];
   NSLog(@"isRestart %d",isRestart);
  }
  else if ( [functionName isEqualToString:@"Update_AfterUpdate"] )
  {
   result = [instance Update_AfterUpdate:&isRestart];   
  }

  [instance release];
 }

}