If you have some old classes/methods that you can’t get rid off, but you dont’ want anyone to use them for new development, you should mark them as deprecated, which can be done with the Obsolete tag:

<Obsolete("Don't use this class")> _
Public Class Whatever

End Class

This will cause any reference to Whatever to produce a warning.  You can treat these as errors if you want by using one of the other constructors like this:

<Obsolete("Don't use this class", True) > _
Public Class Whatever

End Class

Ran into this error today:

failed in property IsDeleted —> System.Reflection.AmbiguousMatchException: Ambiguous match found. at System.RuntimeType.GetPropertyImpl

I knew that we happened to have a property on our class called IsDeleted that shadowed a property in the CSLA base class, but I didn’t think it should be running into this problem.

After tracking down some reference info here http://msdn.microsoft.com/en-us/library/zy0d4103.aspx I found otu that the issue isn’t that we are shadowing, it’s that we are shadowing while at the same time changing the type. 

The documentation seems to indicate that both situations should fail, but in my tests, the only time I got the exception was when my shadowing property had a different type.  In this case, we were using a Nullable(of boolean) while the CSLA element was just a plain old Boolean.

I guess we are going to rename our property to make things easy on ourselves, but seeing as how this is codegenerated, it’s a little more of a pain than you might think.  But, oh well.

Here is some code that produces the error.  If you change the 2nd property type to a string it works ok.

imports Microsoft.VisualBasic
imports System
Imports System.Collections.Generic

public module MyModule
    sub Main
        dim target as new baseclass
        
        dim p as system.Reflection.PropertyInfo  = target.GetType().GetProperty("Prop")
        
        wl( p.GetValue(target, nothing))

        
        RL()
    end sub

    #region "Helper methods"

    sub WL(text as object)
        Console.WriteLine(text)
    end sub

    sub WL(text as object, paramarray args as object())
        Console.WriteLine(text.ToString(), args)
    end sub
        
    sub RL()
        Console.ReadLine()
    end sub
    
    sub Break()
        System.Diagnostics.Debugger.Break()
    end sub

    #end region

end module

public class BaseBaseClass
    public readonly property Prop as string
    get
    return "BaseBaseClass"
    end get
    end property
end class

public class BaseClass
inherits BaseBaseClass

    public readonly property Prop as integer
    get
    return 123
    end get
    end property

end class

The amount of time that this cost me is astounding for such a stupid issue.  (And, I’m going to lay the blame fully on whoever wrote the dbRoot object in the MyGeneration project.  Total improper use of properties).

The situation was this: I was trying to dynamically wire up all the plumbing that the mygeneration windows app does for you manually from the ZeusCmd command line.

Doing this would allow me to switch from DB to DB within my code gen application.

Because ZeusCmd runs first (it references my app and passes in what is needed), if you had previously saved a connection in your MyGeneration app, then this connection is used when ZeusCmd runs.  I didn’t want this to happen because as I move from location to location different DB servers are available or not available, so if the last DB server I connected to was at office A, I didn’t want my code gen crashing onload when I am out of said office.

So I ran MyGeneration and changed my connection to be <None> and saved the settings.  Then in my code gen, I tried to manually create the dbRoot object (named meta here) that was previously created for me my ZeusCmd and my saved MyGeneration settings.

Code like this:

meta.Connect("SQL", "Provider=SQLNCLI;Server=cmayt61p;Database=DBName;Trusted_Connection=yes;")

Seemed to do the trick.

However, my codegen started blowing up on my later in the process.  After tracking down the error I find that the mygeneration result column object can’t figure out the .net type that would be the same as a sql server “int”.  Strange, never had these problems before.

A lot of debugging leads me to find that:

meta.DbTarget
meta.Language 

Are both returning “” when before they were returning “SqlClient” and “VB.NET” when I was not dynamically connecting.

So here is where things get bad… anytime I try setting these properties to their values:

meta.DbTarget = "SqlClient"
meta.Language = "VB.NET"

Nothing happens.  The values don’t appear to stick.

Eventually I even start trying to set the LanguageMappingFileName and DbTargetMappingFileName properties as well:

meta.DbTarget = "SqlClient"
meta.Language = "VB.NET"
meta.LanguageMappingFileName = "C:Program FilesMyGeneration13SettingsLanguages.xml"
meta.DbTargetMappingFileName = "C:Program FilesMyGeneration13SettingsDbTargets.xml"

I tried doing these property sets before connecting and after connecting.

I tried returning to having MyGeneration setup the meta object form me (and all these properties have their values) before dynamically connecting (and losing the DbTarget and Language property values).

I even tried creating a brand new dbRoot object, as well as trying to read some hidden values in the IZeusInput object.

But, in the end, it all came down to the this 1 little thing:

You have to set the mapping file properties before you can set the DbTarget and Language properties.

So this will work just fine:

meta.Connect("SQL", "Provider=SQLNCLI;Server=cmayt61p;Database=MSiUpgraded;Trusted_Connection=yes;")
meta.LanguageMappingFileName = "C:Program FilesMyGeneration13SettingsLanguages.xml"
meta.DbTargetMappingFileName = "C:Program FilesMyGeneration13SettingsDbTargets.xml"
meta.DbTarget = "SqlClient"
meta.Language = "VB.NET"

But this won’t:

meta.Connect("SQL", "Provider=SQLNCLI;Server=cmayt61p;Database=MSiUpgraded;Trusted_Connection=yes;")
meta.DbTarget = "SqlClient"
meta.Language = "VB.NET"
meta.LanguageMappingFileName = "C:Program FilesMyGeneration13SettingsLanguages.xml"
meta.DbTargetMappingFileName = "C:Program FilesMyGeneration13SettingsDbTargets.xml"

It just so happened that everywhere that I was testing this stuff in my code, I always set the DbTarget and Language properties first, and they would never stick.

This is not a proper use of properties.  If a property set has conditional logic that will prevent it from setting, there is something wrong here.  At minimum something should happen, an exception being thrown maybe?  The proper thing to do in my mind would be to make DbTarget and Language readonly properties and have functions to set their value, which could return something indicating failure (or throw an exception).

Property gets and sets should do just that, get and set properties.  There shouldn’t be logic in there deciding if and when to actually perform the set that you have coded.  That is the job of a function.

UPDATE: And I discovered as well that you have to connect first before you set any of these values, or none of them will stick.  So you have to 1) connect 2) set the file paths 3) set the language and dbtargets, in that order or nothing works.

From this post:
http://forums.lhotka.net/forums/thread/25658.aspx

Child pattern:

[Serializable]
public class Child : BusinessBase<Child>
{
  internal static Child NewChild()
  {
    return DataPortal.CreateChild<Child>();
  }

  internal static Child GetChild()
  {
    return DataPortal.FetchChild<Child>();
  }

  private Child()
  {
    MarkAsChild();
  }

  private void Child_Create()
  {
    // initialize new child here
  }

  private void Child_Fetch()
  {
    // load child data here
  }

  private void Child_Insert()
  {
    // insert child data here
  }

  private void Child_Update()
  {
    // update child data here
  }

  private void Child_DeleteSelf()
  {
    // delete child data here
  }
}

Editable root pattern:

[Serializable]
public class RootParent : BusinessBase<RootParent>
{
  // other class code here ...

  protected override void DataPortal_Insert()
  {
    using (SqlConnection cn = new SqlConnection(...))
    {
      // insert parent data here

      FieldManager.UpdateChildren();
    }
  }

  protected override void DataPortal_Update()
  {
    using (SqlConnection cn = new SqlConnection(...))
    {
      // update parent data here

      FieldManager.UpdateChildren();
    }
  }
}

Editable Root List:

[Serializable]
public class ChildList : BusinessListBase<ChildList, Child>
{
  // other class code here ...

  protected override void DataPortal_Update()
  {
    using (SqlConnection cn = new SqlConnection(...))
    {
      Child_Update();
    }
  }
}

Editable Child List:

[Serializable]
public class ChildList : BusinessListBase<ChildList, Child>
{
  internal ChildList()
  {
    MarkAsChild();
  }

  // other class code here ...
}

If you use the DataPortal methods for creating the child objects (i.e. FetchChild) then you don’t have to bother with the MarkAsChild() stuff.

From time to time you might have an enum that you want to databind to something as if it were a list, so I wrote some classes that turn an Enum into a list that you can databind. 

I created ways to do this in CSLA and also w/o CSLA.  I made the non-CSLA versions 1 work so that you can either use a sub class, or just use generics when defining the type of your list.  You can do the same with the CSLA versions if you want by changing some of the generics, but I didn’t bother.

'*** csla
Dim cslaList As MyTestTypeList = MyTestTypeList.GetList

'*** non-csla with inherited subclass and without
Dim list As New MyTestTypeList2
Dim list2 As New EnumList2(Of MyTestType)

'*** enum we are using
Public Enum MyTestType
    something = 1
    here = 2
    ok = 3
End Enum

'*** csla
<Serializable()> _
Public Class MyTestTypeList
    Inherits EnumList(Of mytesttype, MyTestTypeList)

End Class
<Serializable()> _
Public Class EnumList(Of T As Structure, R As EnumList(Of T, R))
    Inherits Csla.NameValueListBase(Of String, Integer)

    Public Shared Function GetList() As R
        Return Csla.DataPortal.Fetch(Of R)()
    End Function

    Protected Sub New()
        ' require use of factory method 
    End Sub

    <Csla.RunLocal()> _
    Public Overloads Sub DataPortal_Fetch() 'ByVal criteria As Object)
        Me.IsReadOnly = False
        For Each item As T In [Enum].GetValues(GetType(T))
            Dim name As String = [Enum].GetName(GetType(T), item)
            Add(New Csla.NameValueListBase(Of String, Integer).NameValuePair(name, [Enum].Parse(GetType(T), name)))
        Next
        Me.IsReadOnly = True
    End Sub 
End Class

'*** non-csla
Public Class MyTestTypeList2
    Inherits EnumList2(Of MyTestType)

End Class

Public Class EnumList2(Of T As Structure)
    Inherits List(Of EnumListItem)

    Public Structure EnumListItem
        Dim Name As String
        Dim Value As Integer
        Public Sub New(ByVal name As String, ByVal value As Integer)
            Me.Name = name
            Me.Value = value
        End Sub
    End Structure 

    Public Sub New()
        For Each item As T In [Enum].GetValues(GetType(T))
            Dim name As String = [Enum].GetName(GetType(T), item)
            Add(New EnumListItem(name, [Enum].Parse(GetType(T), name)))
        Next
    End Sub

End Class