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.
Related
I am wondering if there is a way to get XmlSerializer in C# to change what it outputs for one property of one object. For example, if I have something like:
public class MyClass
{
public string prop1{get;}
public uint prop2{get;}
public MyClass2 class2{get;}
public MyClass3 class3{get;}
}
public class MyClass2
{
public string prop3{get;}
}
public class MyClass3
{
//Lots of properties that I want to serialize as normal
}
Now in somewhere in my code, I have something like this:
private void SerializeStuff(List<MyClass> list, string path)
{
XmlSerializer serialize = new XmlSerializer(typeof(List<MyClass>));
TextWriter writer = new StreamWriter(path);
serialize.Serialize(writer, list);
writer.Close();
}
What I want is for the serialization to work as normal, but with prop3 replaced with some other stuff. Example:
<MyClass>
<prop1>whatever</prop1>
<prop2>345</prop2>
<class2>
<somethingNotProp3>whatever</somethingNotProp3>
<somethingElseNotProp3>whatever</somethingElseNotProp3>
</class2>
<class3>
...
</class3>
</MyClass>
Is there a way to customize XmlSerializer so I don't have to write the entire Xml file manually, or is there no way to do that?
Edit:
I am pretty sure that the solution could have something to do with implementing ISerializable's GetObjectData method; however, I am not exactly sure how to implement it. I tried making MyClass2 inherit from ISerializable and implementing GetObjectData, but nothing changed. prop3 was still output in the XML file.
Use the attributes in the System.Xml.Serialization namespace to affect the way that the instance is serialized.
If you need very specialized serialization for MyClass3 that the attributes cannot handle, then implement the IXmlSerializable interface which will give you complete control over the serialization process (you can even decide on an instance-by-instance basis how to serialize the content/property).
Based on the comments, it would seem that you want to implement IXmlSerializable, as you want to change the name of the property and the value; the attributes will let you change the name of the property/element/attribute, but not allow you to perform transformations on the value (and I assume you don't want to corrupt your representation and add an extra property/value for this purpose).
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...
Can anyone explain how to control the XML generated ?
I have a simple test class, NumberService ...
[Serializable]
public class NumberService
{
public int Number1 { get; set; }
public int Number2 { get; set; }
}
Now if I use an XmlSerializer to deserialise an instance, I get what I expected ...
<NumberService>
<Number1>23</Number1>
<Number2>45</Number2>
</NumberService>
but I was attempting to send this and Fiddler was showing ...
<NumberService>
<_x003C_Number1_x003E_k__BackingField>10</_x003C_Number1_x003E_k__BackingField>
<_x003C_Number2_x003E_k__BackingField>2</_x003C_Number2_x003E_k__BackingField>
</NumberService>
Poking around I've read that this is because of my use of automatic properties, and indeed if I changed to ...
public class NumberService
{
private int _number1;
public int Number1
{
get { return _number1; }
set { _number1 = value; }
}
public int Number2 { get; set; }
}
indeed the XML changes to ...
<NumberService>
<_number1>4</_number1>
<_x003C_Number2_x003E_k__BackingField>6</_x003C_Number2_x003E_k__BackingField>
</NumberService>
But of course I can't change _number1 to Number1 as it'd conflict with the property :-(
So how can you control the XML ?
... and a bit more reading ...
this is involving WCF data contracts
This has to do with how the DataContractSerializer handles items with the Serializable attribute applied.
When confronted with the Serializable attribute, the DataContractSerializer will defer to the semantics that you would expect when using the instance with an IFormatter implementation; in other words, it will serialize the underlying fields using the names of the fields as the keys to the data.
Because you are using auto-generated properties, what you are seeing is actually the names of the auto-generated fields that the compiler generates for you.
In order to get around this, you should apply the DataContract attribute to the class and the DataMember attribute to the properties (and you can control the name by specifying it in the attribute if you want it to differ from the property name).
You also have the option of not specifying the DataContract/DataMember attributes at all and using POCO DataContract serialization; this assumes you have a default parameterless constructor along with only serializing public properties/fields.
You should remove the [Serializable] attribute. It is not used by XML Serialization, and it is giving the wrong message to the Data Contract Serializer.
If you are using just XmlSerialization then you can use attributes from System.Xml.Serialization namespace to control Xml-Serialization for example XmlAttributeAttribute.
If you wand to use DataContractSerializer in your Wcf service, you need to mark your class with DataContract attribute and mark all properties with DataMember attribute.
IMHO DataContractSerializer is much more advanced, than old XmlSerialization
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
For example I want to remove or change below property attributes or add a new one. Is it possible?
[XmlElement("bill_info")]
[XmlIgnore]
public BillInfo BillInfo
{
get { return billInfo; }
set { billInfo = value; }
}
(edit - I misread the original question)
You cannot add actual attributes (they are burned into the IL); however, with XmlSerializer you don't have to - you can supply additional attributes in the constructor to the XmlSerializer. You do, however, need to be a little careful to cache the XmlSerializer instance if you do this, as otherwise it will create an additional assembly per instance, which is a bit leaky. (it doesn't do this if you use the simple constructor that just takes a Type). Look at XmlAttributeOverrides.
For an example:
using System;
using System.Xml.Serialization;
public class Person
{
static void Main()
{
XmlAttributeOverrides overrides = new XmlAttributeOverrides();
XmlAttributes attribs = new XmlAttributes();
attribs.XmlIgnore = false;
attribs.XmlElements.Add(new XmlElementAttribute("personName"));
overrides.Add(typeof(Person), "Name", attribs);
XmlSerializer ser = new XmlSerializer(typeof(Person), overrides);
Person person = new Person();
person.Name = "Marc";
ser.Serialize(Console.Out, person);
}
private string name;
[XmlElement("name")]
[XmlIgnore]
public string Name { get { return name; } set { name = value; } }
}
Note also; if the xml attributes were just illustrative, then there is a second way to add attributes for things related to data-binding, by using TypeDescriptor.CreateProperty and either ICustomTypeDescriptor or TypeDescriptionProvider. Much more complex than the xml case, I'm afraid - and doesn't work for all code - just code that uses the component-model.
It is not possible to add/remove attributes from a class at runtime.
It is possible however to update the way XML serialization works at runtime without needing to edit attributes. See Marc's post.
EDIT Updated