Question

When serializing/de-serializing certain classes I’ve come across the need to flag or mark certain properties as CDATA elements (due to their content). I am currently handling this like so:

    <XmlElement('MessageText')> _     Public Property XmlContentLeft() As XmlCDataSection         Get             Dim doc As New XmlDataDocument()             Dim cd As XmlCDataSection = doc.CreateCDataSection(Me.MessageText)             Return cd         End Get         Set(ByVal value As XmlCDataSection)             Me.MessageText = value.Value         End Set     End Property      <XmlIgnore()> _     Public Property MessageText() As String         Get             Return _messageText         End Get         Set(ByVal value As String)             _messageText= value         End Set     End Property 

Now while this works great it has drawbacks — I now have duplicate properties for anything I want to be a CDATA element and I have to write extra code for these properties.

So my question is whether or not there is a better way to do this? I don’t want to have to write custom schemas or serialization routines for each class. In an ideal scenario I’d be able to add an attribute to these properties so they are automatically treated as CDATA elements.

Answer 1

Two things:

1) You can simplify your existing CDATA code like this:

<XmlElement('MessageText')> _ Public Property XmlContentLeft() As XmlCDataSection     Get         return GetCData(Me.MessageText)     End Get     Set(ByVal value As XmlCDataSection)         Me.MessageText = value.Value     End Set End Property  ' this method is re-usable by any property that needs CData Private Function GetCData(ByVal value As String) As XmlCDataSection     Static doc As New XmlDataDocument()      return doc.CreateCDataSection(value) End Function  <XmlIgnore()> _ Public Property MessageText() As String     Get         Return _messageText     End Get     Set(ByVal value As String)         _messageText= value     End Set End Property 

Of course that’s actually more code than you posted, but note that your CData property is now much simpler. Also, my use of Static isn’t a typo or C# mistake. VB.Net has a little-known Static keyword for creating members in functions. This way the XmlDataDocument is only created once for the entire class and doesn’t pollute your class’s private namespace.

2) The serializer should already properly escapes character data. Do you really need it to be CData? Anything you serialize should be properly deserialized to match the original, even things like code strings. The only case I can thing where you might need a CDATA section is if you have to conform to a schema that’s expecting it.