Parent Child?

webdad3 posted on Sunday, August 05, 2007

Wal972 replied on Sunday, August 05, 2007

You can look at the Project Tracker example. its really good, very helpful

Ellie

JoeFallon1 replied on Monday, August 06, 2007

Jeff,

Here is some sample code that you can examine to see how the pattern is implemented.

===========================================================================================================

  <Serializable()> _
  Public Class MyRootBO
    Inherits MyBusinessBase(Of MyRootBO)

    'private fields here

    Protected mChildColl As ChildColl

    Protected Overrides Sub DataPortal_Update()
      Dim tr As IDbTransaction = Nothing

      Try
        tr = BeginTransaction()
        DoUpdate(tr)
        EndTransaction(tr)
      Catch ex As Exception
        RollbackTransaction(tr)
        Throw
      End Try
    End Sub

    Protected Overridable Sub DoUpdate(ByVal tr As IDbTransaction)
      Dim user As MyUser
      user = DirectCast(Thread.CurrentPrincipal, MyUser)

      UpdateData(tr, user)
      PostUpdateData(tr, user)
      UpdateChildren(tr)
    End Sub

    Protected Overridable Sub UpdateData(ByVal tr As IDbTransaction, ByVal user As MyUser)
      DAL.ExecuteNonQuery(tr, CommandType.Text, GetSQL.Update(..., user.Userkey))
    End Sub

    Protected Overridable Sub UpdateChildren(ByVal tr As IDbTransaction)
      ChildColl.Update(tr, DirectCast(Me, MyRootBO))
    End Sub

===========================================================================================================

'childColl BO sample code

    Protected Friend Overridable Sub Update(ByVal tr As IDbTransaction, ByVal MyRootBO As MyRootBO)
      RaiseListChangedEvents = False

      For Each child As MyChild In DeletedList
        child.Update(tr, Item)
      Next

      DeletedList.Clear()

      For Each child As MyChild In Me
        child.Update(tr, Item)     
      Next

      RaiseListChangedEvents = True
    End Sub

===========================================================================================================
'child BO sample code

    Protected Friend Overridable Sub Update(ByVal tr As IDbTransaction, ByVal MyRootBO As MyRootBO)
      If Not Me.IsDirty Then
        Exit Sub
      End If

      Dim user As MyUser
      user = DirectCast(Thread.CurrentPrincipal, MyUser)

      If Me.IsDeleted Then
        If Not Me.IsNew Then
          DeleteChildren(tr)
          DAL.ExecuteNonQuery(tr, CommandType.Text, GetChildSQL.Delete(mKey))
          PostDeleteData(tr, user)
        End If
        MarkNew()
      Else
        If Me.IsNew Then
          InsertData(tr, MyRootBO, user)
          PostInsertData(tr, user)
        Else
          UpdateData(tr, user)
          PostUpdateData(tr, user)
        End If
        UpdateChildren(tr)
        MarkOld()
      End If
    End Sub

    Protected Overridable Sub DeleteChildren(ByVal tr As IDbTransaction)
      'marker method that can be overridden in child class
    End Sub

    Protected Overridable Sub InsertData(ByVal tr As IDbTransaction, ByVal MyRootBO As MyRootBO, ByVal user As MyUser)
      DAL.ExecuteNonQuery(tr, CommandType.Text, GetChildSQL..Insert(MyRootBO.Key,..., user.Userkey))
    End Sub

    Protected Overridable Sub UpdateData(ByVal tr As IDbTransaction, ByVal user As MyUser)
      DAL.ExecuteNonQuery(tr, CommandType.Text, GetChildSQL.Update(..., user.Userkey))
    End Sub

    Protected Overridable Sub UpdateChildren(ByVal tr As IDbTransaction)
      'marker method that can be overridden in child class
    End Sub