rollbackroot.vb

C# 版本的一个三层商业架构

<Serializable()> _
Public Class RollbackRoot
  Inherits BusinessBase

  Private mData As String = ""
  Private mFail As Boolean = False

  Public Property Data() As String
    Get
      Return mData
    End Get
    Set(ByVal Value As String)
      If mData <> Value Then
        mData = Value
        MarkDirty()
      End If
    End Set
  End Property

  Public Property Fail() As Boolean
    Get
      Return mFail
    End Get
    Set(ByVal Value As Boolean)
      If mFail <> Value Then
        mFail = Value
        MarkDirty()
      End If
    End Set
  End Property



  <Serializable()> _
  Private Class Criteria
    Public Data As String

    Public Sub New()
      Data = "<new>"
    End Sub

    Public Sub New(ByVal Data As String)
      Me.Data = Data
    End Sub
  End Class

  Public Shared Function NewRoot() As RollbackRoot
    Return DirectCast(DataPortal.Create(New Criteria), RollbackRoot)
  End Function

  Public Shared Function GetRoot(ByVal Data As String) As RollbackRoot
    Return DirectCast(DataPortal.Fetch(New Criteria(Data)), RollbackRoot)
  End Function

  Public Shared Sub DeleteRoot(ByVal Data As String)
    DataPortal.Delete(New Criteria(Data))
  End Sub


  Private Sub New()
    ' prevent direct creation
  End Sub

  Protected Overrides Sub DataPortal_Create(ByVal Criteria As Object)
    Dim crit As Criteria = DirectCast(Criteria, Criteria)
    mData = crit.Data
    Session.Add("Root", "Created")
  End Sub

  Protected Overrides Sub DataPortal_Fetch(ByVal Criteria As Object)
    Dim crit As Criteria = DirectCast(Criteria, Criteria)
    mData = crit.Data
    MarkOld()
    Session.Add("Root", "Fetched")
  End Sub

  Protected Overrides Sub DataPortal_Update()

    'BeginEdit()
    Try
      If IsDeleted Then
        ' we would delete here
        Session.Add("Root", "Deleted")
        MarkNew()
      Else
        If IsNew Then
          ' we would insert here
          Session.Add("Root", "Inserted")

        Else
          ' we would update here
          Session.Add("Root", "Updated")
        End If
        MarkOld()

        If mFail Then Throw New Exception("fail update")

      End If
      'ApplyEdit()

    Catch
      'CancelEdit()
      Throw
    End Try

  End Sub

  Protected Overrides Sub DataPortal_Delete(ByVal Criteria As Object)
    ' we would delete here
    Session.Add("Root", "Deleted")
  End Sub

  Protected Overrides Sub Deserialized()
    MyBase.Deserialized()
    Session.Add("Deserialized", "root Deserialized")
  End Sub

  Protected Overrides Sub Serialized()
    MyBase.Serialized()
    Session.Add("Serialized", "root Serialized")
  End Sub

  Protected Overrides Sub Serializing()
    MyBase.Serializing()
    Session.Add("Serializing", "root Serializing")
  End Sub

End Class