FancyTree how to set parent of a node to unselectable if it has no children

I know how to do this for one particular child node, but my problem is that I need to be able to iterate through the fancyTree and (using selectMode: 3) deem whether a node should be checked or not based on whether any of it's child Nodes have children.

I know this sounds confusing so an example would be a top level node called 'TopNode' with 2 children 'T2Node1' && 'T2Node2'. I want the node to stay selected if either of the two children have children of their own, otherwise set the node and its parent to unselectable.

My fancyTree code:

        $("#surveyTargetTree").fancytree({
        activeVisible: true,
        checkbox: true,
        extensions: ["filter", "glyph", "clones"],
        glyph: {
            map: {
                doc: "fa fa-user",
                folder: "fa fa-folder",
                folderOpen: "fa fa-folder-open text-primary",
                loading: "fa fa-spinner fa-pulse"
            }
        },
        selectMode: 3,
        filter: {
            mode: "hide",
            autoApply: true
        },
        source: collectiveJson...,        

        click: function (e, data) {
            var treeDisabled = $("#surveyTargetTree").hasClass("ui-fancytree-disabled");
            if (treeDisabled == false) {
                var nodeType = data.node.refKey.split('_')[0];
                var nodeParentType = data.node.parent.key.split('_')[0];
                var emptyCount = 0;

                if (nodeType == "adGroup" && nodeParentType == "OU" && data.targetType == "title") {
                    ViewGroupUsers(data.node.refKey);
                }

                if (data.targetType == "checkbox" && (nodeType != "aduser" && nodeType != "emailuser")) {

                    if (data.node.children == null) {
                        data.node.unselectable = true;
                        ErrorNotification('ErrorNotification');
                        data.node.render();
                        return false;
                    }
                    else 
                    {
                        ProcessChildren(data.node);
                    }}
            }
            data.node.render();
        }

and the recursive function..

function ProcessChildren(node)
    {
        var blah = 0;
        var selectedNodes = [];

        if (node.children != null) {
            for (var i = 0; i < node.children.length; i++) {

                var nodeType = node.children[i].refKey.split('_')[0];
                if (node.children[i].children == null && (nodeType != "aduser" && nodeType != "emailuser")) {

                    node.children[i].unselectable = true;
                    blah++;
                }
                else
                {
                    ProcessChildren(node.children[i])

                }
            }
        }
    }

If someone can point me in the right direction i'd appreciate it.

via bjjrolls