Using lots of trial and error, I finally found a solution. Or, rather a hack. In Pharo 3: Just set autoRefreshOnExpand to true, and then when there is need for update, do: self widget treeModel updateList In Pharo 4: For some reason autoRefreshOnExpand was removed, and now we also have to manually reset children of all (at least all affected nodes). Something like this: node widget widget setChildren: node widget childrenBlock (where node is instance of TreeNodeModel; root nodes can be obtained by calling self widget treeModel rootNodes collect: #nodeModel) However as this solution uses some implementation details, expect it to break at any time. Hey, they even change public API without warning (like mentioned autoRefreshOnExpand). -- View this message in context: http://forum.world.st/Spec-TreeModel-dynamic-contents-tp4827440p4827812.html Sent from the Pharo Smalltalk Users mailing list archive at Nabble.com.