CSLA Light : Serializing a Class to handle Composite Keys

mjr0607 posted on Monday, February 09, 2009

Hi all.  Newbie with a question...

I'm using CSLA Light to display a ReadOnlyList in a Silverlight DataGrid control -- works fine.  My intention is to allow the user to select a record from the list and open an Edit form for that record.  My ReadOnlyList should therefore contain keys.  Here's the rub -- my db utilizes (and must continue to utilize) composite keys.

So I created a class that creates the keys for me.  But when I attempt to LoadProperty in my BO, I get an error:

LoadProperty<string>(KeyProperty, OrderKey.Create().SetKeys(this).ToString());

But I'm not sure that's desirable.  In the following link, Rocky suggests using strings for keys, but wouldn't that involve the subsequent parsing of those strings to extract the individual values -- values that could otherwise be referenced as properties of a key object?

http://forums.lhotka.net/forums/1/457/ShowThread.aspx

So I have a couple questions:

1. Does anyone have a suggested/preferred solution for making an unknown class known to the data contract serializer?  I'm not sure whether CSLA has facilities to do this.

2. Does anyone have direct experience and/or suggestions using CSLA with a composite key db?  What are the pros/cons of using a key class vs. a string?

Thanks in advance for any thoughts.

sergeyb replied on Monday, February 09, 2009

mjr0607 replied on Tuesday, March 10, 2009

Sergey,

Thanks for the response.  Following a brief distraction, I'm finally back on this project.  I tried your first suggestion of deriving the OrderKey class from BusinessBase.  That worked fine, but as expected, there's a lot of overhead. Populating a grid with 10,000 orders takes 10 seconds without keys and 24 seconds with keys.

I then tried creating a nested OrderKey class within my OrderInfo business class as follows:

[Serializable]

public partial class OrderKey

   public string OrderClass { get; set; }

   public string OrderNumber { get; set; }

   public static OrderKey Create()

      return new OrderKey();

   public OrderKey SetKeys(OrderInfo theOrderInfo)

      this

      return this;

   public OrderKey SetOrderClass(string theOrderClass)

      this.OrderClass = theOrderClass;

      return this;

   public OrderKey SetOrderNumber(string theOrderNumber)

      this.OrderNumber = theOrderNumber;

      return this;