XML Elements Move Inside New Descendant with Linq to XML C#?

Question

I have this XML document:

<aaa>
    <x1></x1>
    <x2></x2>
    <x3></x3>
</aaa>

And need to convert it to this document:

<aaa>
    <bbb note="moved to new">
        <x1></x1>
        <x2></x2>
        <x3></x3>   
    </bbb>
</aaa>

Using Linq-to-XML, what would be the right code to add all child nodes of to a new descendant , but only if descendant does not exist? I started with this

var docRaw = XElement.Parse( documentString );
var bbbElem = docRaw.Elements( "aaa" ).Where( docRaw => !docRaw.Elements( "bbb" ).Any() );

But I think that takes me down the wrong strategy-path.

All ideas appreciated, thanks.

Answer 1

You can use ReplaceNodes() to replace the content of the root element. You can replace them with a new node named <bbb> that contains the root's former child elements.

doc.Root.ReplaceNodes(
    new XElement("bbb",
        new XAttribute("note", "moved to new"),
        doc.Root.Elements()
    )
);