BaseClass + DerivedClass + Serialization -- Dirty

[Michael Maes]

Hi,

I have a BaseClass from which many Classes Derive.
In short: the BaseClass provides the functionalities (Methods) and the Derived Classes extend it with Properties.
One of the (Base) Functionalities is to (De)Serialize the Objects.

Deserialization is performed in the BaseClass
Friend Function PerformDeserialization(ByVal path As String, ByVal user As String) As Object
Debug.WriteLine("Settings.BaseSettings.PerformDese rialization")
If Not path.EndsWith("\") Then path += "\"
If user Is Nothing Then user = Me.ProductFamily
Dim cls As Object
If File.Exists(path + user + FilePrefix + CallerClass + ".xml") = True Then
Dim srFile As StreamReader = New StreamReader(path + user + FilePrefix + CallerClass + ".xml")
Dim t As Type
Dim pi As PropertyInfo()
Dim p As PropertyInfo
Try
xmlSerializer = New Xml.Serialization.XmlSerializer(Me.GetType())
cls = xmlSerializer.Deserialize(srFile)
t = cls.GetType
pi = t.GetProperties()
For Each p In pi
If p.PropertyType.Equals(GetType(System.String)) Then
p.SetValue(cls, Crypto.DecryptString(CType(p.GetValue(cls, Nothing), String)), Nothing)
End If
Next
Catch ex As Exception
Debug.WriteLine(ex.ToString) : Beep()
Finally
srFile.Close()
End Try
Else
Dim ClassType As Type = Me.GetType()
cls = Activator.CreateInstance(ClassType, True)
End If
InstanceHashCode = cls.GetHashCode
InstanceCreated = True
MarkClean(cls)
Return cls
End Function
An object is marked DIRTY by the Set of the Properties in the Derived Classes. (eg)
Private _connectionName As String
Public Property ConnectionName() As String
Get
Return _connectionName
End Get
Set(ByVal Value As String)
Debug.WriteLine("Settings.TestData.Set_ConnectionN ame")
If _connectionName = Value Then Exit Property
_connectionName = Value : MarkDirty(Me)
End Set
End Property
Serialization is called through the Public-Method 'Object'.Persist.
In that Sub I check the Flag IsDirty (Function in BaseClass) to determine if the Object *should* be Serialized or not.
Private mIsDirty As Boolean = False
Public Overridable ReadOnly Property IsDirty() As Boolean
Get
Return mIsDirty
End Get
End Property

The problem is that after Deserialization (I have Called MarkClean(cls)) all the properties seem to be re-Set (So they MarkDirty again). This is causing my Objects to be Always dirty. I can't seem to find a Point (within the (base)Class) to MarkClean effectively.

My guess is that this is Serialization-Behavior.

Does anyone have any ideas?

TIA,

Michael

[Gary Chang]

Hi Michael

Currently I am looking for somebody who could help you on it. We will reply
here with more information as soon as possible.
If you have any more concerns on it, please feel free to post here.
Thanks for your understanding!

Best regards,

Gary Chang
Microsoft Online Partner Support

Get Secure! - www.microsoft.com/security
This posting is provided "AS IS" with no warranties, and confers no rights.
--------------------

[Michael Maes]

Hi Gary,

Thanks for your reply.
I'm looking foreward for any advise on this matter.

Kind regards,

Michael

[Peter Huang]

Hi Michael,

I think we can try to set the TrackDirty to be false temporarily at the
beginning of PerformDeserialization and set it back to true at the end of
PerformDeserialization, so that the deserialize procedure will not call the
MarkDirty.

You may have a try and let me know the result.
Best regards,

Peter Huang
Microsoft Online Partner Support

Get Secure! - www.microsoft.com/security
This posting is provided "AS IS" with no warranties, and confers no rights.

[Michael Maes]

Hi Peter,

This seems to be impossible, because:
° 'Me' is another instance (There are 2: One of the default constructor
& one from the Desarialization)
° If you change a value from an object that's in the process of being
deserialized BEFORE it's returned to the Caller, then 'Nothing' gets
returned.

I think the problem is still unsolved here.

Kind regards,

Michael

""Peter Huang"" <v-******@online.microsoft.com> wrote in message
news:Kw*************@cpmsftngxa06.phx.gbl...

Hi Michael,

I think we can try to set the TrackDirty to be false temporarily at the
beginning of PerformDeserialization and set it back to true at the end of
PerformDeserialization, so that the deserialize procedure will not call the MarkDirty.

You may have a try and let me know the result.
Best regards,

Peter Huang
Microsoft Online Partner Support

Get Secure! - www.microsoft.com/security
This posting is provided "AS IS" with no warranties, and confers no rights.

[Jay B. Harlow [MVP - Outlook]]

Michael,
Do you have a sample of where you call this code?

How are MarkDirty & MarkClean implemented, I would expect them to be
instance methods without parameters.

Private mIsDirty As Boolean = False
Public Overridable ReadOnly Property IsDirty() As Boolean
Get
Return mIsDirty
End Get
End Property

Protected Sub MarkDirty()
mIsDirty = True
End Sub

Protected Sub MarkClean()
mIsDirty = True
End Sub

I would expect PerformDeserialization to be a Shared method, otherwise it
appears that you need to create an instance of your object, to read an
instance of you object, where you throw away the first instance. With a
Shared method you will only create the instance that was read.

You do know you can use System.IO.Path.Combine to create path strings? &
System.IO.Path.ChangeExtension to add/replace the extension of a path
string?

path = System.IO.Path.Combine(path, user + FilePrefix + CallerClass)
path = System.IO.Path.ChangeExtension(path, ".xml")

In this case ChangeExtension may not be as useful, however Combine will
check for the trailing & leading path separators for you ("\" & "/").

Hope this helps
Jay
"Michael Maes" <mi*****@merlot.com> wrote in message
news:un*************@TK2MSFTNGP10.phx.gbl...
Hi,

I have a BaseClass from which many Classes Derive.
In short: the BaseClass provides the functionalities (Methods) and the
Derived Classes extend it with Properties.
One of the (Base) Functionalities is to (De)Serialize the Objects.

Deserialization is performed in the BaseClass
Friend Function PerformDeserialization(ByVal path As String, ByVal user As
String) As Object
Debug.WriteLine("Settings.BaseSettings.PerformDese rialization")
If Not path.EndsWith("\") Then path += "\"
If user Is Nothing Then user = Me.ProductFamily
Dim cls As Object
If File.Exists(path + user + FilePrefix + CallerClass + ".xml") = True
Then
Dim srFile As StreamReader = New StreamReader(path + user +
FilePrefix + CallerClass + ".xml")
Dim t As Type
Dim pi As PropertyInfo()
Dim p As PropertyInfo
Try
xmlSerializer = New
Xml.Serialization.XmlSerializer(Me.GetType())
cls = xmlSerializer.Deserialize(srFile)
t = cls.GetType
pi = t.GetProperties()
For Each p In pi
If p.PropertyType.Equals(GetType(System.String)) Then
p.SetValue(cls,
Crypto.DecryptString(CType(p.GetValue(cls, Nothing), String)), Nothing)
End If
Next
Catch ex As Exception
Debug.WriteLine(ex.ToString) : Beep()
Finally
srFile.Close()
End Try
Else
Dim ClassType As Type = Me.GetType()
cls = Activator.CreateInstance(ClassType, True)
End If
InstanceHashCode = cls.GetHashCode
InstanceCreated = True
MarkClean(cls)
Return cls
End Function
An object is marked DIRTY by the Set of the Properties in the Derived
Classes. (eg)
Private _connectionName As String
Public Property ConnectionName() As String
Get
Return _connectionName
End Get
Set(ByVal Value As String)
Debug.WriteLine("Settings.TestData.Set_ConnectionN ame")
If _connectionName = Value Then Exit Property
_connectionName = Value : MarkDirty(Me)
End Set
End Property
Serialization is called through the Public-Method 'Object'.Persist.
In that Sub I check the Flag IsDirty (Function in BaseClass) to determine if
the Object *should* be Serialized or not.
Private mIsDirty As Boolean = False
Public Overridable ReadOnly Property IsDirty() As Boolean
Get
Return mIsDirty
End Get
End Property

The problem is that after Deserialization (I have Called MarkClean(cls)) all
the properties seem to be re-Set (So they MarkDirty again). This is causing
my Objects to be Always dirty. I can't seem to find a Point (within the
(base)Class) to MarkClean effectively.

My guess is that this is Serialization-Behavior.

Does anyone have any ideas?

TIA,

Michael

[Peter Huang]

Hi Michael,

I am sorry if I have any misunderstanding.
In addition to Jay's suggestion.
Now I want to restate the senario.
1. Use the StartMarkingDirty to set the TrackDirty to true, so that the
following changing to the object will set the IsDirty to true.
2. In the constructor to set the TrackDirty to true, in this way the
changing to the object will set the IsDirty to true including the
deserialization process which you do not want.
If I have any misunderstanding, please feel free to let me know.

Also by default, the deserialization will call the constructor to recreate
the object from the file, so now I think we have two approaches.
1. Use the StartMarkingDirty method to explicitly set the TrackDirty to
true.
2. in the contructor to know which one is call the constructor, if it is
the DeSerialization, then we can set the TrackDirty to false.
Public Sub New()
Debug.WriteLine("Settings.BaseSettings.New - Me.GetHashCode: "
& Me.GetHashCode.ToString)
Dim st As New StackTrace(True)
TrackDirty = True
If st.FrameCount >= 10 Then
Dim sf As StackFrame = st.GetFrame(10)
If sf.GetMethod().Name <> "PerformDeserialization" Then
TrackDirty = False
End If
End If
CallerClass = Me.GetType.Name.ToString.ToLower()
Crypto = New RijndaelSimple
End Sub

You may try the code below to print out all the callstack.
StackTrace Class
http://msdn.microsoft.com/library/de...us/cpref/html/
frlrfsystemdiagnosticsstacktraceclasstopic.asp
Best regards,

Peter Huang
Microsoft Online Partner Support

Get Secure! - www.microsoft.com/security
This posting is provided "AS IS" with no warranties, and confers no rights.

[Michael Maes]

Hi Jay,

Thanks for your reply.
It must be something silly here, but I'm so "Short-Circuited" on this that I can't see "the wood through the forrest" (if that's said in English) anymore.

I give you the two classes (Base & Derived) with all the methods of interest to this thread.

Option Strict Off
Imports System.IO
Imports System.Xml.Serialization
'Imports Stegosoft.Security
'Imports Stegosoft.Security.DotFuscator
Imports System.ComponentModel
Imports System.Reflection
Namespace Settings
''' -----------------------------------------------------------------------------
''' Project : StegoSettings
''' Class : Settings.BaseSettings
'''
''' -----------------------------------------------------------------------------
''' <summary>
'''
''' </summary>
''' <remarks>
''' </remarks>
''' <history>
''' [Michael.Maes] 6/12/2003 Created
''' [Michael.Maes] 30/06/2004 Transform to better OO
''' </history>
''' -----------------------------------------------------------------------------
'<Serializable(), _
'SkipRenaming(), _
'DebuggerStepThrough()> _
Public MustInherit Class BaseSettings
#Region " Declarations "
Private Shared xmlSerializer As xmlSerializer
Private Shared Crypto As RijndaelSimple
Private Shared FilePrefix As String = ".cfgsettings."
Protected Friend Shared CallingAssembly As [Assembly]
Private TrackDirty As Boolean = False
#End Region
#Region " Constructors "
Public Sub New()
Debug.WriteLine("Settings.BaseSettings.New - Me.GetHashCode: " & Me.GetHashCode.ToString)
Dim st As New StackTrace(True)
TrackDirty = True
If st.FrameCount >= 10 Then
Dim sf As StackFrame = st.GetFrame(10)
If sf.GetMethod().Name <> "PerformDeserialization" Then
TrackDirty = False
End If
End If
'CallerClass = Me.GetType.Name.ToString.ToLower()
'Crypto = New RijndaelSimple
End Sub
Friend Sub Instanciate()
Debug.WriteLine("Settings.BaseSettings.Instanciate ")
GetProductFamily()
GetCompany()
End Sub
Private Function GetProductFamily() As String
Debug.WriteLine("Settings.BaseSettings.GetProductF amily")
Dim t As Type = GetType(AssemblyDefaultAliasAttribute)
Dim r() As Object = CallingAssembly.GetCustomAttributes(t, False)
If IsNothing(r) Or r.Length = 0 Then
Return Nothing
Else
_ProductFamily = CType(r(0), AssemblyDefaultAliasAttribute).DefaultAlias
Return _ProductFamily
End If
End Function
Private Function GetCompany() As String
Debug.WriteLine("Settings.BaseSettings.GetCompany" )
Dim t As Type = GetType(AssemblyCompanyAttribute)
Dim r() As Object = CallingAssembly.GetCustomAttributes(t, False)
If IsNothing(r) Or r.Length = 0 Then
Return Nothing
Else
_Company = CType(r(0), AssemblyCompanyAttribute).Company
Return _Company
End If
End Function
#End Region
#Region " Properties "
Dim _ProductFamily As String = Nothing
Friend ReadOnly Property ProductFamily() As String
Get
If IsNothing(_ProductFamily) Then _ProductFamily = GetProductFamily()
Return _ProductFamily
End Get
End Property
Dim _Company As String = Nothing
Friend ReadOnly Property Company() As String
Get
If IsNothing(_Company) Then _Company = GetCompany()
Return _Company
End Get
End Property
Public Sub StartMarkingDirty() 'ByVal Instance As Object)
Debug.WriteLine("Settings.BaseSettings.StartMarkin gDirty".ToUpper & Me.GetHashCode)
TrackDirty = True
End Sub
Private mIsDirty As Boolean = False
Public Overridable ReadOnly Property IsDirty() As Boolean
Get
Return mIsDirty
End Get
End Property
Protected Sub MarkDirty()
Debug.WriteLine("Settings.BaseSettings.MarkDirty")
If TrackDirty Then mIsDirty = True
End Sub
Protected Sub MarkClean()
mIsDirty = False
End Sub

#End Region
#Region " Load "
'Public Overridable Function Load(ByVal path As String, Optional ByVal user As String = Nothing) As Object
' Debug.WriteLine("Settings.BaseSettings.Load")
' Return PerformDeserialization(path, user)
'End Function
Friend Shared Function PerformDeserialization(ByVal CallerClass As Object, ByVal path As String, ByVal user As String) As Object
Debug.WriteLine("Settings.BaseSettings.PerformDese rialization")
If Not path.EndsWith("\") Then path += "\"
If user Is Nothing Then user = CallerClass.ProductFamily
Dim cls As Object
If File.Exists(path + user + FilePrefix + CallerClass.GetType.Name.ToString.ToLower() + ".xml") = True Then
Debug.WriteLine("Settings.BaseSettings.New - Me.GetHashCode: " & CallerClass.GetHashCode.ToString)
Crypto = New RijndaelSimple
Dim srFile As StreamReader = New StreamReader(path + user + FilePrefix + CallerClass.GetType.Name.ToString.ToLower() + ".xml")
Dim t As Type
Dim pi As PropertyInfo()
Dim p As PropertyInfo
Try
xmlSerializer = New Xml.Serialization.XmlSerializer(CallerClass.GetTyp e())
cls = xmlSerializer.Deserialize(srFile)
t = cls.GetType
pi = t.GetProperties()
For Each p In pi
If p.PropertyType.Equals(GetType(System.String)) Then
'p.SetValue(cls, Crypto.DecryptString(CType(p.GetValue(cls, Nothing), String)), Nothing)
p.SetValue(cls, (CType(p.GetValue(cls, Nothing), String)), Nothing)
End If
Next
Catch ex As Exception
Debug.WriteLine(ex.ToString)
MsgBox(ex.ToString)
Finally
srFile.Close()
End Try
Else
Dim ClassType As Type = CallerClass.GetType()
cls = Activator.CreateInstance(ClassType, True)
End If
Return cls
End Function
#End Region
#Region " Persist "
Public Sub Persist(ByVal path As String, Optional ByVal user As String = Nothing)
Debug.WriteLine("Settings.BaseSettings.Persist")
If user Is Nothing Then user = Me.ProductFamily
PerformSerialization(Me, path, user)
End Sub
Private Sub PerformSerialization(ByVal CallerClass As Object, ByVal path As String, ByVal user As String)
Debug.WriteLine("Settings.BaseSettings.PerformSeri alization")
If Not path.EndsWith("\") Then path += "\"
Dim FileName As String = path + user.ToLower + FilePrefix + CallerClass.GetType.Name.ToString.ToLower() + ".xml"
Dim swFile As StreamWriter = New IO.StreamWriter(FileName)
Dim t As Type = Me.GetType()
Dim pi As PropertyInfo()
Dim p As PropertyInfo
pi = t.GetProperties()
' Encrypt Strings
For Each p In pi
If p.PropertyType.Equals(GetType(System.String)) Then
'p.SetValue(Me, Crypto.EncryptString(CType(p.GetValue(Me, Nothing), String)), Nothing)
p.SetValue(Me, (CType(p.GetValue(Me, Nothing), String)), Nothing)
End If
Next
' Save to Disk
xmlSerializer = New Xml.Serialization.XmlSerializer(t)
xmlSerializer.Serialize(swFile, Me)
swFile.Close()
End Sub
#End Region
End Class
End Namespace

--------------------------------------------------------------------------------

Namespace Settings
''' -----------------------------------------------------------------------------
''' Project : StegoSettings
''' Class : Settings.TestData
'''
''' -----------------------------------------------------------------------------
''' <summary>
'''
''' </summary>
''' <remarks>
''' </remarks>
''' <history>
''' [Michael.Maes] 6/12/2003 Created
''' [Michael.Maes] 30/06/2004
''' </history>
''' -----------------------------------------------------------------------------
<Serializable()> Public Class TestData
Inherits Settings.BaseSettings
'Public Sub New()
' MyBase.New()
' Debug.WriteLine("Settings.TestData.New - Me.GetHashCode: " & Me.GetHashCode.ToString)
' CallingAssembly = Me.GetType.Assembly.GetCallingAssembly
' MyBase.Instanciate()
'End Sub
#Region " Load "
Public Shadows Function Load(ByVal path As String, Optional ByVal user As String = Nothing) As TestData
Debug.WriteLine("Settings.TestData.Load")
Try
'StartMarkingDirty()
Debug.WriteLine("Settings.TestData.New - Me.GetHashCode: " & Me.GetHashCode.ToString)
CallingAssembly = Me.GetType.Assembly.GetCallingAssembly
MyBase.Instanciate()
Dim cls As TestData = DirectCast(PerformDeserialization(Me, path, user), TestData)
Debug.WriteLine("************** cls Calling StartMarkingDirty: " & cls.GetHashCode)
StartMarkingDirty()
Return cls
Catch ex As Exception
Return Nothing
End Try
End Function
#End Region
Private _connectionName As String
Public Property ConnectionName() As String
Get
Return _connectionName
End Get
Set(ByVal Value As String)
Debug.WriteLine("Settings.TestData.Set_ConnectionN ame")
_connectionName = Value : MarkDirty()
End Set
End Property
End Class
End Namespace
--------------------------------------------------------------------------------
I'dd be more than greatfull if you'd come up with a solution.

Kind regards,

Michael

[Cor Ligthert]

Hi Michael,

I do your first question, than can Jay take the rest again (I did not follow
this thread), however that one about the trees I found funny. I think it is
"Unable to see the wood for the trees", the same as with us I thought (I
have this from a book full of those, however far from complete).

Cor

[Jay B. Harlow [MVP - Outlook]]

Cor,
Actually its "Unable to see the forest for the trees".

http://www.wordwizard.com/clubhouse/...1.asp?Num=3769

I actually like John Pursel's variation.

Although Wood & Forest can be synonymous

Jay

"Cor Ligthert" <no**********@planet.nl> wrote in message
news:%2****************@TK2MSFTNGP12.phx.gbl...

Hi Michael,

I do your first question, than can Jay take the rest again (I did not follow this thread), however that one about the trees I found funny. I think it is "Unable to see the wood for the trees", the same as with us I thought (I
have this from a book full of those, however far from complete).

Cor

[Michael Maes]

I think (hope) my dutch is better then my english.....

I am in the middle of founding a new company, moving our office, hire staff,
..... so I guess that's a lousy excuse for messing things up :-(

Michael