DynamicObject and WCF support

Question

I was wondering if anyone has had any luck getting a DynamicObject to serialize and work with WCF?

Here’s my little test:

[DataContract]
class MyDynamicObject : DynamicObject
{
    [DataMember]
    private Dictionary<string, object> _attributes =
       new Dictionary<string, object>();

    public override bool TryGetMember(GetMemberBinder binder, out object result)
    {
        string key = binder.Name;

        result = null;

        if (_attributes.ContainsKey(key))
            result = _attributes[key];

        return true;
    }

    public override bool TrySetMember(SetMemberBinder binder, object value)
    {
        _attributes.Add(binder.Name, value);

        return true;
    }
}

var dy = new MyDynamicObject();
var ser = new DataContractSerializer(typeof(MyDynamicObject));
var mem = new MemoryStream();
ser.WriteObject(mem, dy);

The error I get is:

System.Runtime.Serialization.InvalidDataContractException was unhandled Message=Type 'ElasticTest1.MyDynamicObject' cannot inherit from a type that is not marked with DataContractAttribute or SerializableAttribute. Consider marking the base type 'System.Dynamic.DynamicObject' with DataContractAttribute or SerializableAttribute, or removing them from the derived type.

Any suggestions?

Answer 1

Solution for your problem

Implement custom IDynamicMetaObjectProvider

Answer 2

Can you use something like Dictionary<TKey, TValue> to achieve this?

I am trying to solve a similar problem. My issue is that I have DTO's to transfer data between client and server. However, you should always have DTO's that are fine grained and flattened.

For example, if a client wants to get Customer's Name and ID and it is not interested in anything else, ideally, you should create a DTO that only has these 2 properties in it. If you were to transfer the same CustomerDTO for all methods, there is a lot of performance implications. You could be transferring a lot of redundant fields.