How to collapse tree node with no children

Question

Using ExtJs 4.2.

I have a tree panel where all nodes have arrow for expanding. On expanding a node with children, the arrow for collapsing remains. However, on expanding a node without children, the arrow of the node disappears. So there is no collapsing possible on that node.

How to keep the arrow and collapsing functionality on a node without children?

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See the screenshot: both nodes (on the same level, black) are expanded, however only the node with children has a arrow for collapsing again.

Answer 1

AFAIK double-clicking the node toggles expand/collapse. I've tested it in 4.0.0.

Edit:
It has probably changed in Ext4.2 though. The empty folder node seems to be always open (with no children inside). I guess the reason might be to clearly indicate it's empty node to the user (without even interacting with it).

Answer 2

So far we are solving this problem by checking for children on an expand event. If there are no children, we collapse the node again without the user taking note.