Discussion Around Parameterized Content

Given the class…

public class Person
{
    private IList<Person> _friends = new List<Person>();

    public Person(string name)
    {
        Name = name;
    }

    public Person()
    {
    }

    public string Name { get; set; }

    public IList<Person> Friends
    {
        get => _friends;
        set => _friends = value ?? throw new ArgumentNullException();
    }
}

And invoking it as such:

       var snoopy = new Person("Snoopy");
        var charlieBrown = new Person("Charles \"Charlie\" Brown");
        var sallyBrown = new Person("Sally Brown");
        var marcie = new Person("Marcie");

        snoopy.Friends.Add(charlieBrown);
        snoopy.Friends.Add(sallyBrown);
        snoopy.Friends.Add(marcie);
        snoopy.Friends.Add(charlieBrown); // added twice -- intentional

       var serializer = new ConfigurationContainer().EnableParameterizedContent().EnableReferences().Create();
        
        var serializedPerson = serializer.Serialize(snoopy);
        snoopy = serializer.Deserialize<Person>(serializedPerson);

The serialization will all work as expected, but an exception will be thrown on deserialization:

The value "ExtendedXmlSerializer.ExtensionModel.Types.ActivationContext" is not of type "ExsTests.Person" and cannot be used in this generic collection. Parameter name: value

If you comment out the last Friends.Add then the object will be properly deserialized but snoopy will be an empty object - no Friends, no Name. Please fix poor ol’ Snoopy!

[FaustoNascimento]

This issue is resolved and can be closed, yes. Although could you explain exactly what the extension WritableParameterizedContentExtension (as per #196) does?

It seems to me like it just allows public setters on properties set by the ctor, but not sure if that’s the case?

[FaustoNascimento]

You have to keep in mind that we have basically shelved this version as we work towards v3.

Apologies, wasn’t aware of this, thought that while you were working towards v3, that v2 was still being actively maintained and improved (rather than just bug fixing).

I agree it’s not ideal but it seems that you are under the impression that it is the project that is blocking you here.

Well, not quite. Redesigning my classes is not really an option (having an empty private ctor is an option but it feels like dodging the problem rather than fixing it). But I don’t see it as this project blocking me. I’ve always had alternatives but I thought that v2 was still being actively worked on and that as such I was contributing to this project by highlighting things that are important for developers like myself.

I don’t mind creating my own extensions and submitting a PR when they’re done - I’d actually prefer it since I’d end up with the knowledge about how to create my own extensions. But right now I don’t feel like I know enough about all of the different classes involved to create my own.

So long as you’re happy to potentially devoting more time to teaching me what each class does than what it would take you to implement it I have no problems with creating an extension and submitting a PR.