Wicketeers, I have another hard-to-track down issue.
To make matters worse, I've actually taken this code/pattern, put it into a quickstart - and what do you know - it works fine...! This means I have no way to recreate this error in a demonstrable way. Hopefully if I throw this out there, someone might be able to describe the error and I can then determine what I'm doing to cause it. Unfortunately google has zero results for; +"Components can no longer be added" +wicket Anyway... the exception I'm getting is; java.lang.IllegalStateException: Components can no longer be added at org.apache.wicket.ajax.AbstractAjaxResponse.assertNotFrozen(AbstractAjaxResponse.java:740) at org.apache.wicket.ajax.AbstractAjaxResponse.assertComponentsNotFrozen(AbstractAjaxResponse.java:733) at org.apache.wicket.ajax.AbstractAjaxResponse.add(AbstractAjaxResponse.java:358) at org.apache.wicket.ajax.AjaxRequestHandler.add(AjaxRequestHandler.java:239) at org.apache.wicket.ajax.AjaxRequestHandler.add(AjaxRequestHandler.java:232) at org.apache.wicket.extensions.markup.html.repeater.tree.TableTree.updateBranch(TableTree.java:178) at org.apache.wicket.extensions.markup.html.repeater.tree.AbstractTree.expand(AbstractTree.java:204) at myapp.TreeUtils.expandNode(TreeUtils.java:25) at myapp.TreeUtils.expandAll(TreeUtils.java:19) It is caused when refreshing a table-tree component, that had previous rendered correctly and had successfully expanded the nodes. This problem happens when the table-trees parent component is refreshed, in which the table is rebuilt from new, and replaced the old table. Having debugged the code, it's something to do with the AjaxRequestHandler that has been retrieved - in that it's components are 'frozen'. It's odd as I'm in the onConfigure() part of the lifecycle, and therefore components should be okay to be added - especially as they are brand new components. Could the AjaxRequestHandler being retrieved be the wrong one, stale one? List I said - I can't recreate it in a Quickstart, so there is obviously something else in the 100k+s of the projects code that is doing something else to mess it up. The 'Tree Utils' class looks like this; public class TreeUtils { @SuppressWarnings("unchecked") public static void expandAll( AbstractTree<?> tree ) { // stupid cast!! Has to happen for use to retrieve the roots, generically. AbstractTree<Object> castTree = (AbstractTree<Object>) tree; Iterator<?> roots = tree.getProvider().getRoots(); while( roots.hasNext() ) { Object root = roots.next(); expandNode( castTree, root ); } } private static void expandNode( AbstractTree<Object> tree, Object node) { tree.expand(node); Iterator<?> children = tree.getProvider().getChildren(node); while( children.hasNext() ) { Object child = children.next(); expandNode( tree, child ); } } } Any pointers and tips would be greatly appreciated. Cheers, Col. EMAIL DISCLAIMER This email message and its attachments are confidential and may also contain copyright or privileged material. If you are not the intended recipient, you may not forward the email or disclose or use the information contained in it. If you have received this email message in error, please advise the sender immediately by replying to this email and delete the message and any associated attachments. Any views, opinions, conclusions, advice or statements expressed in this email message are those of the individual sender and should not be relied upon as the considered view, opinion, conclusions, advice or statement of this company except where the sender expressly, and with authority, states them to be the considered view, opinion, conclusions, advice or statement of this company. Every care is taken but we recommend that you scan any attachments for viruses.