Primefaces Tree node is draggable to children - jsf

Question

I have a PrimeFaces (6.2.5) tree, where I have enabled draggable and droppable. I have a few issues with this, and have implemented the drag and drop manually with jquery in stead, while I figure this out;
<div class="plantree" id="realplantree">
<p:tree id="plantree" value="#{curriculumngTreeFacade.root}" var="node" dynamic="false" selectionMode="single" selection="#{curriculumngTreeFacade.selectedNode}" draggable="true" droppable="true">
<p:ajax event="select" listener="#{curriculumngTreeFacade.onNodeSelect}" update="administration-form:curriculummain" oncomplete="initDNDPlan();"/>
<p:ajax event="expand" listener="#{curriculumngTreeFacade.onNodeExpand}" />
<p:ajax event="collapse" listener="#{curriculumngTreeFacade.onNodeCollapse}" />
<p:ajax event="dragdrop" listener="#{curriculumngTreeFacade.onDragDrop}"/>
<p:treeNode expandedIcon="ui-icon ui-icon-folder-open" collapsedIcon="ui-icon ui-icon-folder-collapsed">
<h:outputText value="#{node}"/>
</p:treeNode>
</p:tree>
</div>
My issues are:
I have not added an "update='plantree'" variable to the p:ajax event
for dragdrop. Even still, if I try and drag a parent category to a
sub category, it breaks my tree, because the UI tries to update. I
actually run a check for parent / child connection in the backend
code, and I dont update the tree if that's the case, but in this
case, my method in the backing bean is not even called before the
tree explodes. It does the very same on the PrimeFaces Showcase
Backing code:
public void onDragDrop(TreeDragDropEvent event) throws Exception {
TreeNode dragNode = event.getDragNode();
TreeNode dropNode = event.getDropNode();
int dropIndex = event.getDropIndex();
if (dragNode.getData() instanceof CurriculumCategoryMetaModel && dropNode.getData() instanceof CurriculumCategoryMetaModel) {
CurriculumCategoryMetaModel drop = (CurriculumCategoryMetaModel) dropNode.getData();
CurriculumCategoryMetaModel drag = (CurriculumCategoryMetaModel) dragNode.getData();
if (drop.getType() == drag.getType() && drag.getClassid() > 0) {
drag.setParent(drop);
CurriculumBuilderProvider provider = CurriculumBuilderProvider.getProvider(drop.getType());
provider.saveCategory(drag, UserSessionFacade.getUserLocale());
this.initialize();
expandCategory(root, drop.getClassid(), drop.getType());
} else {
this.initialize();
}
}
FacesMessage message = new FacesMessage(FacesMessage.SEVERITY_INFO, "Dragged " + dragNode.getData(), "Dropped on " + dropNode.getData() + " at " + dropIndex);
FacesContext.getCurrentInstance().addMessage(null, message);
List<String> updates = new ArrayList<>();
updates.add("administration-form:curriculummenu");
updates.add("administration-form:growl");
PrimeFaces.current().ajax().update(updates);
}
private boolean dragIsParentOfDrop(CurriculumCategoryMetaModel drop, CurriculumCategoryMetaModel drag) {
CurriculumCategoryMetaModel parent = drop.getParent();
while (parent != null) {
if (parent.getClassid() == drag.getClassid()) {
return true;
} else {
parent = parent.getParent();
}
}
return false;
}
Is there a way to add accepted nodes that you can drop into. I have 2
root nodes, for different categories, and it is not allowed to drag
and drop between them. In fact, I dont even want the root nodes to be
draggable. On the picture, the "Learning paths" and "Ad hoc" are not supposed to be draggable, since they're only containers for the categories underneath.