Question

I have a graph object, that I need to serialize. Nomatter which members i implement, the method returns {}

string json = new JavascriptSerializer().Serialize(routeGraph);

Here is my graph class:

namespace GraphClass
{
    [Serializable, DataContract]
    public class Graph : ISerializable
    {
        [DataMember]
        readonly Dictionary<string, Node> nodeMap = new Dictionary<string, Node>();
        [DataMember]
        private Tuple<string, string, double> bufferOriginalOffer;
    }
    [Serializable, DataContract]
    public class Node : ISerializable
    {
        [DataMember]
        public string Name { get; private set; }
        [DataMember]
        public List<Edge> Adj { get; private set; }
        [DataMember]
        public Node Prev { get; set; }
        [DataMember]
        public double Distance { get; set; }
    [Serializable, DataContract]
    public class Edge : IComparable, ISerializable
    {
        [DataMember]
        public Node Destination { get; private set; }
        [DataMember]
        public double Cost { get; set; }
        [DataMember]
        public double Time { get; set; }
    }
    [Serializable, DataContract]
    public class Tuple<T, T1, T2> : ISerializable
    {
        [DataMember]
        public T Item1 { get; set; }
        [DataMember]
        public T1 Item2 { get; set; }
        [DataMember]
        public T2 Item3 { get; set; }
    }
}

I’ve tried for a whole day, to serialize this to either JSON or XML, as I have to send the object to a webservice.

UPDATE:
Used DataContractJsonSerialiser instead. I get the following error:

Object graph for type 'GraphClass.Edge' contains cycles and cannot be serialized if reference tracking is disabled.

As you can see in the Node class, a Node can contain a list of edges. I’m at a loss about fixing the error though.

Answer 1

Did you perhaps intend to use DataContractJsonSerializer ? This is more data-contract oriented; JavascriptSerializer doesn’t really care at all about data-contracts – it just looks at the type meta.

Graph only has private fields; JavascriptSerializer only looks at public members. Add a public property for nodeMap, perhaps?

Note that [Serializable] does nothing here, and those types don’t implement ISerializable etc, despite claiming to.

---

Edit: confirmed the following seems to work OK:

DataContractJsonSerializer ser = new DataContractJsonSerializer(graph.GetType());
string s;
using(var ms = new MemoryStream()) {
    ser.WriteObject(ms, graph);
    s = Encoding.UTF8.GetString(ms.GetBuffer(), 0, (int)ms.Length);
}
Console.WriteLine(s);

and the following seems to work after adding a property:

public Dictionary<string, Node> NodeMap { get { return nodeMap; } }
...
JavaScriptSerializer ser = new JavaScriptSerializer();
string s = ser.Serialize(graph);
Console.WriteLine(s);