DataContract Serialize abstract class

Question

I have an interface IServiceInfo and an abstract class ServiceInfo. There are several classes inherited from ServiceInfo, like CoreServiceInfo, ModuleServiceInfo etc. There is a service contract named RootService which returns IServiceInfo.

 public IServiceInfo GetServiceInfo()
 {
     return (IServiceInfo)new CoreServiceInfo();
 }

I am having problem serializing. I can use ServiceKnownType to identify base class, and KnownType to identify child class.

Problem is I do not know all the ServiceInfo child, since application can have plugins with different child inherited from ServiceInfo, so I cannot tell serializer to have all the child in serialized XML.

I can ignore abstract class, but it contains certain common implementation so I need to keep it. As a work around I can have another class say "sampleServiceInfo" and convert all the info classes to sampleServiceInfo and return it from Service method, and define KnownType to ServiceInfo class.

[KnownType(typeof(sampleServiceInfo))]
public class ServiceInfo : IServiceInfo

But that does not sound pretty way to do it. Please suggest. Do I need to write custom serializer? Is there any way to serialize base only and ignoring the child when both has same members?

How do you expect .NET to know about your derived class if you don't know about it yourself? — John Saunders, Dec 21 '10 at 03:47
that's the boundary, application contains pluggable services — hungryMind, Dec 21 '10 at 05:42

score 7 · Accepted Answer · edited May 23 '17 at 12:10

7

Get all the types in all loaded assemblies that implement given abstract class or interface(ref:Implementations of interface through Reflection)

 var allTypes =  AppDomain
            .CurrentDomain
            .GetAssemblies()
            .SelectMany(assembly => assembly.GetTypes())
            .Where(type => typeof(A).IsAssignableFrom(type));

Then create serializer passing allTypes as known types parameter, as below

var serializer = new DataContractSerializer(typeof(A), allTypes);

that's it - you will be able to serialize and deserialize any type that derives from A (A could be class or interface, if interface, serializer writes elements as deriving from xs:anyType.

edited May 23 '17 at 12:10

Community

1
1

answered Dec 21 '10 at 04:24

Om Deshmane

808
6
11

Thanks mho, so finally i need to write custom serializer. I was expecting some class level attribute to ignore serialization, or some nice pattern, or something like that. Great and thanks anyway. – hungryMind Dec 21 '10 at 05:47
@hungryMind if that answered the question you would do well to mark it as such by checking the mark underneath the vote-spinner. – jcolebrand Dec 26 '10 at 15:43

DataContract Serialize abstract class

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