Implicit Collections are not symmetric in inheritance heirarchy

– From Walt Dixon –

Lets say I have an XML document:

<outer>
<inner id="1"/>
...
<inner id="n"/>
</outer>

That has an underlying class structure like:

public class Node {
private String id;
private Node parent;
private ArrayList children = new ArrayList();
...
}

public class Outer extends Node {
...
}

public class Inner extends Node {
...
}

With the following aliases - and the implicit
collection directive - the xml file unmarshalls
fine

xs.alias("outer", Outer.class);
xs.alias("inner", Inner.class);
xs.addImplicitCollection(Outer.class, "children");

However, marshalling the objects back to XML produces
asymmetric results. (i.e. the collection is now explicit)

<outer>
<children>
<inner id="1"/>
...
<inner id="n"/>
</children>
</outer>

I did however find that by adding an implicit collection
to Node - it marshaled properly?

xs.addImplicitCollection(Node.class, "children");

Is this intentional - it seems a bit asymmetric?

With the xs.addImplicitCollection(Outer.class, "children")
The children aren't unmarshalled correctly

And without the
xs.addImplicitCollection(Node.class, "children");
The children aren't marshalled correctly.