How can I force Fancytree to render nodes with ext-table?

[bpromasmb]

[This is copied from my StackOverflow question since I think this issue might be about more than just me not knowing how to use fancytree]

I have two fancytree tables, and I can drag a node from one tree to the other. Once I drag the node I dynamically add a set number of children to the dragged node, which all have input fields in the next column, rendered via renderColumn.

The problem I'm facing is that the columns are not showing in my HTML until I manually expand the dragged node, and I need to validate the input fields associated to the children.

I tried iterating node by node and forcing each to render individually:

visit_node.addChildren([
    //child nodes...
]);

visit_node.children.forEach(function(childNode){
    childNode.render(true);
});

but to no avail... Is there a way to force these nodes to render? Am I doing something wrong?

Currently I am manually calling setExpanded(true) followed by setExpanded(false) to force rendering, but this is causing performance issues.

EDIT: I have created a jsfiddle showcasing the issue.

Notice that when you drag a node from tree1 to tree2 3 children are created for each "final" folder, however, were I to submit my form without first expanding the folders, there would be no rendered <input> tags to validate. You can verify this by looking at the HTML by pressing F12.

[mar10]

The tree.render(true, true) method should create markup even for hidden nodes, but seems to have a bug. Will try to fix...

[bpromasmb]

Just to add, the same issue affects cases in which I copy and paste a node. Even when the copied node has been rendered, the pasted node does not get rendered.