CODEWITHSUNDEEP
.netxml-serializationcircular-reference
oscilatingcretin
oscilatingcretin

Reputation: 10919

Is it possible for XmlSerializer to support circular references?

I am using the .NET XmlSerializer class to write an XML string to a StringWriter (not WCF or JSON or anything else that involves services).

After hours of trying to find out why I was getting the exception of There was an error generating the XML document after calling XmlSerializer.Serialize(), I finally discovered that it involved a circular reference. My classes look like this:

class Table
{
    public List<Columns> Columns {get; set;}
}

class Column
{
    public Table Table {get; set;}
}

As you can see, a table has a collection of columns, but each column in that collection also holds a reference to its parent table.

I do not want to ignore the property during serialization. I want to be able to deserialize it and not have to rebuild references. Back when I was using WCF, there was a method to preserve references across the wire to reduce the size of the XML. Certainly .NET offers some similar method of serializing circular relationships to XML without compromising the integrity of the XML itself.

Upvotes: 2

Views: 894

Answers (1)

Marc Gravell
Marc Gravell

Reputation: 1062745

No, XmlSerializer does not support this. You mention WCF: WCF doesn't really use XmlSerializer (unless your type is clearly marked for such) - it prefers to use DataContractSerializer, and DataContractSerializer can support circular references, but only be enabling a flag at construction:

var serializer = new DataContractSerializer(typeof(Foo),
    new DataContractSerializerSettings
{
    PreserveObjectReferences = true
});

Note that DataContractSerializerSettings is only in .NET 4.5 and above; prior to that, the same is also available on a constructor overload (the preserveObjectReferences parameter).

Note that XmlSerializer and DataContractSerializer are not 1:1 compatible; they behave differently in many subtle ways.

Upvotes: 4

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