Serialize XML With Attributes Instead of Elements

[grwalker@vt.edu]

I have some classes that have the <Serializable() > attribute applied,
which of course by default serializes the class properties as elements.
What I would like to do is to be able to override this behavior at
runtime to serialize the properties as attributes.

I have been exploring the XMLAttributesOv errides classes and examples
which claims:

"you can create one set of serializable classes, but serialize the
objects in multiple ways. For example, instead of serializing members
of a class instance as XML elements, you can serialize them as XML
attributes, resulting in a more efficient document to transport."

I have yet to be able to figure out how this can be acomplished
however... For a simple class like the following if I call the
SerializeXML() method I get an error.

<Serializable() > _
Public Class Class3

Public Test As String = "Test"
Private Test2 As String = "Test2"
Private Test3 As String = "Test3"

<XmlIgnore()> _
Public Property Test4() As String
Get
Return Test3
End Get
Set(ByVal Value As String)
Test3 = Value
End Set
End Property

Public Sub SerializeXML(By Ref sw As TextWriter)
Dim attrs As New XmlAttributes
Dim attr As New XmlAttributeAtt ribute("MyTest" ,
GetType(String) )
attrs.XmlAttrib ute = attr

Dim attrOverrides As New XmlAttributeOve rrides
attrOverrides.A dd(Me.GetType, "Test", attrs)

Dim xs As New XmlSerializer(G etType(Class3), attrOverrides)
xs.Serialize(sw , Me)
End Sub
End Class

Can someone PLEASE tell me how I can override the behavior at runtime
to serialize as attributes instead of elelements.

[Garry Freemyer]

Re: Serialize XML With Attributes Instead of Elements

Oops. It might help a great deal if you told us what the error was. Sorry,
but it's hilarious to me, I have done this mistake myself. I would think I
would learn to state what the error I got was myself after groaning so many
times when a user would tell me they forgot what the error was and what it
was about and could not even remember enough about it to reproduce the
error.
:)
<grwalker@vt.ed u> wrote in message
news:1117902206 .591012.17460@g 14g2000cwa.goog legroups.com...[color=blue]
>I have some classes that have the <Serializable() > attribute applied,
> which of course by default serializes the class properties as elements.
> What I would like to do is to be able to override this behavior at
> runtime to serialize the properties as attributes.
>
> I have been exploring the XMLAttributesOv errides classes and examples
> which claims:
>
> "you can create one set of serializable classes, but serialize the
> objects in multiple ways. For example, instead of serializing members
> of a class instance as XML elements, you can serialize them as XML
> attributes, resulting in a more efficient document to transport."
>
> I have yet to be able to figure out how this can be acomplished
> however... For a simple class like the following if I call the
> SerializeXML() method I get an error.
>
> <Serializable() > _
> Public Class Class3
>
> Public Test As String = "Test"
> Private Test2 As String = "Test2"
> Private Test3 As String = "Test3"
>
> <XmlIgnore()> _
> Public Property Test4() As String
> Get
> Return Test3
> End Get
> Set(ByVal Value As String)
> Test3 = Value
> End Set
> End Property
>
> Public Sub SerializeXML(By Ref sw As TextWriter)
> Dim attrs As New XmlAttributes
> Dim attr As New XmlAttributeAtt ribute("MyTest" ,
> GetType(String) )
> attrs.XmlAttrib ute = attr
>
> Dim attrOverrides As New XmlAttributeOve rrides
> attrOverrides.A dd(Me.GetType, "Test", attrs)
>
> Dim xs As New XmlSerializer(G etType(Class3), attrOverrides)
> xs.Serialize(sw , Me)
> End Sub
> End Class
>
> Can someone PLEASE tell me how I can override the behavior at runtime
> to serialize as attributes instead of elelements.
>[/color]

[grwalker@vt.edu]

Re: Serialize XML With Attributes Instead of Elements

Garry,

The error was "Error Reflecting Type" on line Dim xs As New
XmlSerializer(G etType(Class3), attrOverrides). I didn't post the error
message originally because I thought it was irrelevant in the context.
All I want to know is if it is possible to control the serialization of
properties at runtime as either elements or attributes using
XMLAttributeOve rrides and how that can be done. My example is probably
negligble as well, but I felt it necessary to throw *something* out
there to give people some idea of what I was attempting. So... I doubt
that error message is particularly helpful, but if you've got any ideas
I'd be willing to listen.

Garry Freemyer wrote:[color=blue]
> Oops. It might help a great deal if you told us what the error was. Sorry,
> but it's hilarious to me, I have done this mistake myself. I would think I
> would learn to state what the error I got was myself after groaning so many
> times when a user would tell me they forgot what the error was and what it
> was about and could not even remember enough about it to reproduce the
> error.
> :)
> <grwalker@vt.ed u> wrote in message
> news:1117902206 .591012.17460@g 14g2000cwa.goog legroups.com...[color=green]
> >I have some classes that have the <Serializable() > attribute applied,
> > which of course by default serializes the class properties as elements.
> > What I would like to do is to be able to override this behavior at
> > runtime to serialize the properties as attributes.
> >
> > I have been exploring the XMLAttributesOv errides classes and examples
> > which claims:
> >
> > "you can create one set of serializable classes, but serialize the
> > objects in multiple ways. For example, instead of serializing members
> > of a class instance as XML elements, you can serialize them as XML
> > attributes, resulting in a more efficient document to transport."
> >
> > I have yet to be able to figure out how this can be acomplished
> > however... For a simple class like the following if I call the
> > SerializeXML() method I get an error.
> >
> > <Serializable() > _
> > Public Class Class3
> >
> > Public Test As String = "Test"
> > Private Test2 As String = "Test2"
> > Private Test3 As String = "Test3"
> >
> > <XmlIgnore()> _
> > Public Property Test4() As String
> > Get
> > Return Test3
> > End Get
> > Set(ByVal Value As String)
> > Test3 = Value
> > End Set
> > End Property
> >
> > Public Sub SerializeXML(By Ref sw As TextWriter)
> > Dim attrs As New XmlAttributes
> > Dim attr As New XmlAttributeAtt ribute("MyTest" ,
> > GetType(String) )
> > attrs.XmlAttrib ute = attr
> >
> > Dim attrOverrides As New XmlAttributeOve rrides
> > attrOverrides.A dd(Me.GetType, "Test", attrs)
> >
> > Dim xs As New XmlSerializer(G etType(Class3), attrOverrides)
> > xs.Serialize(sw , Me)
> > End Sub
> > End Class
> >
> > Can someone PLEASE tell me how I can override the behavior at runtime
> > to serialize as attributes instead of elelements.
> >[/color][/color]

[grwalker@vt.edu]

Re: Serialize XML With Attributes Instead of Elements

Does anyone have any idea how this:

"you can create one set of serializable classes, but serialize the
objects in multiple ways. For example, instead of serializing members
of a class instance as XML elements, you can serialize them as XML
attributes, resulting in a more efficient document to transport."

can be accomplished?

[Chris Lovett]

Re: Serialize XML With Attributes Instead of Elements

Try serializing this:

Imports System.Xml
Imports System.Xml.Seri alization

Public Class Class1

Public Name As String

<XmlAttributeAt tribute()> _
Public Id As Integer

End Class

<grwalker@vt.ed u> wrote in message
news:1118144485 .045349.80790@o 13g2000cwo.goog legroups.com...[color=blue]
> Does anyone have any idea how this:
>
> "you can create one set of serializable classes, but serialize the
> objects in multiple ways. For example, instead of serializing members
> of a class instance as XML elements, you can serialize them as XML
> attributes, resulting in a more efficient document to transport."
>
> can be accomplished?
>[/color]

[grwalker@vt.edu]

Re: Serialize XML With Attributes Instead of Elements

Yes, I know that will work... But you missed the point. I want to
control this behavior at runtime, not design time.

[DC]

Re: Serialize XML With Attributes Instead of Elements

Yes, you can change serialization at runtime, to decide whether to serialize
data as elements or attributes. There is a thing called XML Attribute
overrides, that you can apply at runtime, when de-serializing.

---- Begin sample ----
using System.IO;
using System.Xml.Seri alization;

namespace Ionic {


public class Foo {
public int id;
public System.String name;
public System.Single value;
}


/// <summary>
/// helper class for serializing - omits the XML Declaration line (just
for human readability)
/// </summary>
public class XmlTextWriterFo rmattedNoDeclar ation :
System.Xml.XmlT extWriter {
public XmlTextWriterFo rmattedNoDeclar ation (System.IO.Text Writer w) :
base(w) { Formatting= System.Xml.Form atting.Indented ;}
public override void WriteStartDocum ent () { }
}


public class TestDriver {
public static void Main() {

try {
Foo x= new Foo();

x.id= 7;
x.name= "Theodore Roosevelt";
x.value= 172.33F;

XmlSerializer s1 = new XmlSerializer(t ypeof(Foo));
XmlSerializerNa mespaces ns = new XmlSerializerNa mespaces();
ns.Add( "", "" );


System.Console. WriteLine("----------------------\nserialized as
elements:\n");
System.IO.Strin gWriter stringWriter = new System.IO.Strin gWriter();
System.Xml.XmlW riter xmlWriter = new
XmlTextWriterFo rmattedNoDeclar ation(stringWri ter);
s1.Serialize(xm lWriter, x, ns);

System.Console. WriteLine(strin gWriter.ToStrin g() + "\n\n");

System.Console. WriteLine("----------------------\nserialized as
attributes:\n") ;

XmlAttributeOve rrides overrides = new XmlAttributeOve rrides();
XmlAttributes attributeSet;
XmlAttributeAtt ribute a1;

// provide an Attribute attribute
//

http://msdn.microsoft.com/library/en-us/cpref/html/frlrfSystemXmlSerializationXmlAttributeAttributeClassTopic.asp

a1 = new XmlAttributeAtt ribute("id");

// drop that into an attribute Set
attributeSet = new XmlAttributes() ;
attributeSet.Xm lAttribute= a1;

// add that attribute set for the first field
overrides.Add(t ypeof(Foo), "id", attributeSet);

// do the same thing for the name field
a1 = new XmlAttributeAtt ribute("name");
attributeSet = new XmlAttributes() ;
attributeSet.Xm lAttribute= a1;
overrides.Add(t ypeof(Foo), "name", attributeSet);

// and finally, the same idea for the value field
a1 = new XmlAttributeAtt ribute("value") ;
attributeSet = new XmlAttributes() ;
attributeSet.Xm lAttribute= a1;
overrides.Add(t ypeof(Foo), "value", attributeSet);

// create a new instance of the serializer specifying the overrides
s1 = new XmlSerializer(t ypeof(Foo), overrides);

// serialize as normal
stringWriter = new System.IO.Strin gWriter();
xmlWriter = new XmlTextWriterFo rmattedNoDeclar ation(stringWri ter);
s1.Serialize(xm lWriter, x, ns);
System.Console. WriteLine(strin gWriter.ToStrin g() + "\n\n");

}
catch (System.Excepti on e1) {
System.Console. WriteLine("Exce ption!\n" + e1);
}
}
}
}

---- End sample ----

-Dino
dinoch // Microsoft.com

<grwalker@vt.ed u> wrote in message
news:1118243631 .648366.323190@ o13g2000cwo.goo glegroups.com.. .[color=blue]
> Yes, I know that will work... But you missed the point. I want to
> control this behavior at runtime, not design time.
>[/color]

[grwalker@vt.edu]

Re: Serialize XML With Attributes Instead of Elements

Ahh fantastic! This does indeed work! Apparently the only thing I was
doing incorrectly in my code was attempting to pass a Type to the
constructor of the XmlAttributeAtt ribute. I'm still not sure why this
was causing the serialization to fail, but at least this works! Thanks
much for the help!