How to serialize class members as attributes to xml in C# - c#

I am trying to serialize my object to xml. A serializer seemingly serializes all data members as children, but I want to serialize all members as attributes, not children.
Here's a code example:
[DataContract]
public class MyDataClass
{
[DataMember]
int foo = 24;
[DataMember]
string bar = "brabrabra";
}
This will be serialized as following xml when I use DataContractSerializer:
<MyDataClass xmlns="..." xmlns:i="...">
<foo>24</foo>
<bar>brabrabra</bar>
</MyDataClass>
However, I want to serialize it as following xml somehow:
<MyDataClass xmlns="..." xmlns:i="..." foo="24" bar="brabrabra" />
Is there any way to serialize like that? Or, should I write my own serializer to realize it?
For reference, I am using DataContract serializer in this sample, but I can change it to a normal XmlSerializer or another one if there's a better one.
Hope someone knows about this.
Aki

Have a look at XMLAttribute. Only works with XMLSerializer though.

You can use a simple XmlSerializer to achieve this, in the following way:
[Serializable]
public class SerializationTest2
{
[XmlAttributeAttribute]
public string MemberA { get; set; }
}
[Test]
public void TestSerialization()
{
var d2 = new SerializationTest2();
d2.MemberA = "test";
new XmlSerializer(typeof(SerializationTest2))
.Serialize(File.OpenWrite(#"c:\temp\ser2.xml"), d2);
}

Put [XmlAttribute] before foo and bar declaration.
Great ref: http://msdn.microsoft.com/en-us/library/system.xml.serialization.xmlserializer.aspx

Related

Serialize an object to XML without using attributes

Is it possible to control XmlSerializer/DataContractSerializer behavior without specifying any serialization attributes?
To be more specific, I want to control the serialization (XmlIgnore, custom attribute name etc.), but without decorating my properties.
Use cases:
A large existing class, which I don't wish to pollute with serialization attributes
Serializing a class for which no source code is available
Switching from using XmlSerializer to DataContractSerializer to JSON without changing class code
For example, how would I serialize the following without uncommenting the attributes:
// [Serializable]
public MyClass
{
// [XmlIgnore] - The following property should not be serialized, without uncommenting this line
public int DontSerializeMeEvenThoughImPublic { get; set; }
// [XmlAttribute("another_name")] - should be serialized as 'another_name', not 'SerializeMeAsXmlAttribute'
public double SerializeMeAsXmlAttribute { get; set; }
// [DataMember] - should be included
private string IWantToBeSerializedButDontDecorateMeWithDataMember { get; set; }
}
You can't (do it elegantly).
The only way to modify the way the XmlSerializer serializes classes is by using attributes (by the way SerializableAttribute is not required). The DataContractSerializer is even worse.
One possible solution is to create intermediate classes for XML serialization/desrialization and use Automapper to copy the data between the "real" class and mediator.
I've used this approach to keep the front end XML serialization concerns outside of my business logic data types.
I know this is an old question, but for the XmlSerializer part, it's interesting that no one has suggested the use of Attribute overrides.
Although not solving the Private property, but AFAIK you can't do that with attributes either, so the only route there would be the IXmlSerializable interface.
But what you can do by adding Attributes should be possible with overrides as well.
The following should work for the change wishes reflected by the outcommented XmlAttributes:
public class Program
{
public static void Main()
{
XmlAttributeOverrides overrides = new XmlAttributeOverrides();
overrides.Add(typeof(MyClass), "DontSerializeMeEvenThoughImPublic", new XmlAttributes { XmlIgnore = true });
overrides.Add(typeof(MyClass), "SerializeMeAsXmlAttribute", new XmlAttributes { XmlAttribute = new XmlAttributeAttribute("another_name") });
XmlSerializer serializer = new XmlSerializer(typeof(MyClass), overrides);
using (var writer = new StringWriter())
{
serializer.Serialize(writer, new MyClass());
Console.WriteLine(writer.ToString());
}
}
}
Serialization via XmlSerializer should work without the attributes.

NonSerialized dind't work

i'm serialization a class but i can't exclude some field in my class.
[Serializable]
public class DicData
{
private GDicJson DeserializedGDicJson = new GDicJson();
public UOCDicData BuiltDicData;
[NonSerialized]
public string CacheName = "";
}
in my expection, a public field CacheName didn't include in my *.xml deserialized output, but it included in .xml file.
here are serializing rutine.
XmlSerializer myXml = new XmlSerializer(typeof(DicData), "test");
myXml.Serialize(myFile, this); //note:a serializing perform in method of himself.
For XmlSerializer you want
[XmlIgnore]
Also, note that the [Serializable] is unnecessary in this case.
As a final note: public fields are not encouraged; properties are almos always preferred. The addition of {get;set;} would go a long way...

Public fields/properties of a class derived from BindingList<T> wont serialize

I'm trying to serialize a class that derives from BindingList(Floor), where Floor is a simple class that only contains a property Floor.Height
Here's a simplified version of my class
[Serializable]
[XmlRoot(ElementName = "CustomBindingList")]
public class CustomBindingList:BindingList<Floor>
{
[XmlAttribute("publicField")]
public string publicField;
private string privateField;
[XmlAttribute("PublicProperty")]
public string PublicProperty
{
get { return privateField; }
set { privateField = value; }
}
}
I'll serialize an instance of CustomBindingList using the following code.
XmlSerializer ser = new XmlSerializer(typeof(CustomBindingList));
StringWriter sw = new StringWriter();
CustomBindingList cLIst = new CustomBindingList();
Floor fl;
fl = new Floor();
fl.Height = 10;
cLIst.Add(fl);
fl = new Floor();
fl.Height = 10;
cLIst.Add(fl);
fl = new Floor();
fl.Height = 10;
cLIst.Add(fl);
ser.Serialize(sw, cLIst);
string testString = sw.ToString();
Yet testString above ends getting set to the following XML:
<CustomBindingList xmlns:xsi=\"http://www.w3.org/2001/XMLSchema-instance\" xmlns:xsd=\"http://www.w3.org/2001/XMLSchema\">
<Floor Height="10" />
<Floor Height="10" />
<Floor Height="10" />
</CustomBindingList>"
How do I get "publicField" or "publicProperty to serialize as well?
The short answer here is that .NET generally expects something to be a collection xor to have properties. This manifests in a couple of places:
xml serialization; properties of collections aren't serialized
data-binding; you can't data-bind to properties on collections, as it implicitly takes you to the first item instead
In the case of xml serialization, it makes sense if you consider that it might just be a SomeType[] at the client... where would the extra data go?
The common solution is to encapsulate a collection - i.e. rather than
public class MyType : List<MyItemType> // or BindingList<...>
{
public string Name {get;set;}
}
public class MyType
{
public string Name {get;set;}
public List<MyItemType> Items {get;set;} // or BindingList<...>
}
Normally I wouldn't have a set on a collection property, but XmlSerializer demands it...
XML serialization handles collections in a specific way, and never serializes the fields or properties of the collection, only the items.
You could either :
implement IXmlSerializable to generate and parse the XML yourself (but it's a lot of work)
wrap your BindingList in another class, in which you declare your custom fields (as suggested by speps)
This is known issue with XML serialization and inheriting from collections.
You can read more info on this here : http://social.msdn.microsoft.com/Forums/en-US/asmxandxml/thread/0d94c4f8-767a-4d0f-8c95-f4797cd0ab8e
You could try something like this :
[Serializable]
[XmlRoot]
public class CustomBindingList
{
[XmlAttribute]
public string publicField;
private string privateField;
[XmlAttribute]
public string PublicProperty
{
get { return privateField; }
set { privateField = value; }
}
[XmlElement]
public BindingList<Floor> Floors = new BindingList<Floor>();
}
This means you can add floors by using Floors.Add and you will get the result you want, I hope, however, I didn't try it. Keep in mind that playing around with attributes is the key to XML serialization.

IXmlSerializable

Could you guys help me I have a problem with deserialization via IXmlSerializable
var ArrayOfAccounts = new Accounts(); //This class structure I'm trying to read
Class Accounts:List<Session>{ }
Class Shedule{
public DateTime StartAt { get; set; }
public DateTime EndAt { get; set; }
}
Class Session:IXmlSerializable {
public string Name{get;set;}
public string Pass{get;set;}
public List<Shedule> Shedules = new List<Shedule>();
public void ReadXml(System.Xml.XmlReader reader){
//AND HERE IS A PROBLEM. I don't know how to implement right code here. I've tried
//code below, but this one works for the first account only, and doesn't restore others
Schedules.Clear();
XmlReader subR = reader.ReadSubtree();
if (reader.MoveToAttribute("Name"))
Name = reader.Value;
if (reader.MoveToAttribute("Password"))
Password = reader.Value;
reader.MoveToContent();
while (subR.ReadToFollowing("Schedule"))
{
XmlSerializer x = new XmlSerializer(typeof(Schedule));
object o = x.Deserialize(subR);
if (o is Schedule) Schedules.Add((Schedule)o);
}
}
And the xml itself looks like:
<Accounts>
<Session UserName="18SRO" Password="shalom99">
<Schedule>
<StartAt>0001-01-01T09:30:00</StartAt>
<EndAt>0001-01-01T16:00:00</EndAt>
</Schedule>
</Session>
</Accounts>
Since you've defined the classes, you should just be able to use XML Serialization attributes, and use the default XML deserializer.
Your structure doesn't look overly complicated, is there any particular reason you're not using serialization attributes instead of manually deserializing?
Re inherited fields... if you switch to DataContractSerializer, then fields are "opt in" rather than "opt out" - but you lose the ability to specify attributes (everything is an element). A trivial example:
[DataContract(Name="foo")]
public class Foo
{
[DataMember(Name="bar")]
public string Bar { get; set; }
public int ThisIsntSerialized {get;set;}
}
However - adding unexpected subclasses is a pain for both XmlSerializer and DataContractSerializer. Both can do it, but it isn't pretty...

XmlSerialize a custom collection with an Attribute

I've got a simple class that inherits from Collection and adds a couple of properties. I need to serialize this class to XML, but the XMLSerializer ignores my additional properties.
I assume this is because of the special treatment that XMLSerializer gives ICollection and IEnumerable objects. What's the best way around this?
Here's some sample code:
using System.Collections.ObjectModel;
using System.IO;
using System.Xml.Serialization;
namespace SerialiseCollection
{
class Program
{
static void Main(string[] args)
{
var c = new MyCollection();
c.Add("Hello");
c.Add("Goodbye");
var serializer = new XmlSerializer(typeof(MyCollection));
using (var writer = new StreamWriter("test.xml"))
serializer.Serialize(writer, c);
}
}
[XmlRoot("MyCollection")]
public class MyCollection : Collection<string>
{
[XmlAttribute()]
public string MyAttribute { get; set; }
public MyCollection()
{
this.MyAttribute = "SerializeThis";
}
}
}
This outputs the following XML (note MyAttribute is missing in the MyCollection element):
<?xml version="1.0" encoding="utf-8"?>
<MyCollection xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance" xmlns:xsd="http://www.w3.org/2001/XMLSchema">
<string>Hello</string>
<string>Goodbye</string>
</MyCollection>
What I want is
<MyCollection MyAttribute="SerializeThis"
xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance"
xmlns:xsd="http://www.w3.org/2001/XMLSchema">
<string>Hello</string>
<string>Goodbye</string>
</MyCollection>
Any ideas? The simpler the better. Thanks.
Collections generally don't make good places for extra properties. Both during serialization and in data-binding, they will be ignored if the item looks like a collection (IList, IEnumerable, etc - depending on the scenario).
If it was me, I would encapsulate the collection - i.e.
[Serializable]
public class MyCollectionWrapper {
[XmlAttribute]
public string SomeProp {get;set;} // custom props etc
[XmlAttribute]
public int SomeOtherProp {get;set;} // custom props etc
public Collection<string> Items {get;set;} // the items
}
The other option is to implement IXmlSerializable (quite a lot of work), but that still won't work for data-binding etc. Basically, this isn't the expected usage.
If you do encapsulate, as Marc Gravell suggests, the beginning of this post explains how to get your XML to look exactly like you describe.
http://blogs.msdn.com/youssefm/archive/2009/06/12/customizing-the-xml-for-collections-with-xmlserializer-and-datacontractserializer.aspx
That is, instead of this:
<MyCollection MyAttribute="SerializeThis"
xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance"
xmlns:xsd="http://www.w3.org/2001/XMLSchema">
<Items>
<string>Hello</string>
<string>Goodbye</string>
<Items>
</MyCollection>
You can have this:
<MyCollection MyAttribute="SerializeThis"
xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance"
xmlns:xsd="http://www.w3.org/2001/XMLSchema">
<string>Hello</string>
<string>Goodbye</string>
</MyCollection>
As Neil Whitaker suggests and in case his link dies..
Create an inner collection to store the strings and apply the XmlElement attribute to mask the collection name. Produces the same xml output as if MyCollection inherited from Collection, but also serializes attributes on the parent element.
[XmlRoot("MyCollection")]
public class MyCollection
{
[XmlAttribute()]
public string MyAttribute { get; set; }
[XmlElement("string")]
public Collection<string> unserializedCollectionName { get; set; }
public MyCollection()
{
this.MyAttribute = "SerializeThis";
this.unserializedCollectionName = new Collection<string>();
this.unserializedCollectionName.Add("Hello");
this.unserializedCollectionName.Add("Goodbye");
}
}
I've been fighting with the same issue Romaroo is (wanting to add properties to the xml serialization of a class that implements ICollection). I have not found any way to expose properties that are in the collection class. I even tried using the XmlAttribute tag and making my properties show up as attributes of the root node, but no luck there either. I was however able to use the XmlRoot tag on my class to rename it from "ArrayOf...". Here are some references in case you're interested:
MilkCarton.com
Microsoft Forum Posting
Diranieh - look halfway down
Sometimes you just want to do what you just want to do; the Framework be damned.
I posted an answer here Property of a List<T> Not Deserialized
that does what the OP wanted to do.

Categories

Resources