[System.Text.Json] How to create a new array from existing nodes?

[aventus13]

I have the following code:

var token // property name, type of string
var array // existing array, type of JsonArray

var newArray = new JsonArray();
array.Select(n => n?[token])
    .Where(n => n != null)
    .ToList()
    .ForEach(n => newArray.Add(n!.AsValue()));

However, running this throws the following exception
System.InvalidOperationException : The node already has a parent.

I'm trying to figure out how to create a new JsonArray from existing JsonNode elements. I tried creating new JsonNode elements "manually" but as far as I can see this is not possible, given that many members in System.Text.Json are internal, even the JsonNode constructor.

[huoyaoyuan]

A node isn't supposed to be reference in two trees, or two different positions in tree. You must clone it first before adding to another position.

[aventus13]

@huoyaoyuan thanks for your reply. Yes, I'm aware that a node can only have one parent however that doesn't really answer my question. How can I clone a node? I'm unable to find any Clone method on either the base JsonNode nor any derived types such as JsonArray or JsonObject.

Please note that I'm trying to avoid having to use serialization/deserialization or reflection.

[huoyaoyuan]

You can make an api suggestion for Clone method then.

[danmoseley]

Answered: please use API suggestion template.

[huoyaoyuan]

Cloning is covered by #56592.