Ninject and lifecycle ? RSS

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  thomas_msn01

  Member

  17 Points

  43 Posts

  Ninject and lifecycle ?

  Apr 07, 2012 08:15 PM|LINK

  I'm rather new with MVC3 and Ninject.

  Right now here what I'm using:

  This returns me Ninject Kernel:

  using Ninject;
  
  namespace MasterMindDnet
  {
      public class NinjectKernel
      {
          private static IKernel _Instance = new StandardKernel();
  
          public static IKernel getInstance()
          {
                  return _Instance;
          }
      }
  }

   this returns me an instance of my object.

  private static IKernel NK = NinjectKernel.getInstance();

          public static Game getNinjectInstance()
          {
              IGame iGame;
              try
              {
                  iGame = NK.Get<IGame>(DefaultNinjectNewGameName);
              }
              catch
              {
                  GameParameters ng = GameParameters.getNinjecInstance();
  
                  NK.Bind<IGame>().To<Game>().InSingletonScope().Named(DefaultNinjectNewGameName)
                      .WithConstructorArgument("CodeLength", ng.CodeLength)
                      .WithConstructorArgument("TurnsToBePlayed", ng.Turns)
                      .WithConstructorArgument("DoubleColorAllowed", ng.DoubleColorAllowed)
                      .WithConstructorArgument("GameColors", ng.GameColors)
                      ;
                  iGame = NK.Get<IGame>(DefaultNinjectNewGameName);
              }
              return (Game)iGame;
          }
  

  I want the Game object to be re-usable within a user "session", which means that if he leaves the site this instance won't be used again.

  1 game/user.session

  But in the current situation,it seems that each users will get the same game instance.

  Users may be anonymous. So I guess I could use some aftificial session id, but I'm not sure if it's the right way.

  (You may also suggest a better solution than using a try/catch there, because I'm sure there must be one, but as this works it is not a priority for now.)

  Thank your for your help.

  • Edited by thomas_msn01 on Apr 07, 2012 08:17 PM
  • Edited by thomas_msn01 on Apr 07, 2012 08:17 PM
• • Reply
  

  RemoGloor

  Member

  12 Points

  1 Post

  Re: Ninject and lifecycle ?

  Apr 09, 2012 09:09 PM|LINK

  Hi Thomas

  For the future I suggest that you ask questions regarding Ninject on the Ninject mailinglist or Stackoverflow. The comunity is much more active there.

  Now to your question. I strongly suggest that you think about a solution where you don't need session scoped objects.

  The session scoped objects will be kept in memory for quite a long time (if I remember correctly the session timeout is 20 min). You can run into out of memory problems quite fast if it is not used correctly. Additionally the game will become a 2nd generation gc object which means you will have a lot of 2nd generation garbage collections which dramatically increases the GC running time and the latency of your website at this time. Furthermore, it makes scaling to multiple server instances much more difficult. You have to route users to the same server for the whole session. Also the user won't be able to start a new game during his session. You will have to reuse the previous instance.

  If you still want to have session scoped object then you can do so by adding an object as session scope to HttpContext.Current.Session["SessionScope"] at sesson start

  public void Session_Start()
  {
      HttpContext.Current.Session["SessionScope"] = new object();
  }

  and later you can use it as session scope:

  InScope(HttpContext.Current.Session["SessionScope"])

  I suggest to have a look at Ninject.MVC3 extension. It adds the integration to MVC so that you dont have to add this NinjectKernel singleton so that you can keep your application free from Ninject references.

  Remo

  • Marked as answer by Young Yang - MSFT on Apr 22, 2012 06:17 AM