无法在嵌套TabView中展开TreeTable的节点

Question

When I have a p:treeTable inside p:tabView inside p:tabView as a second tab, I'm unable to expand/collapse the nodes. But this happen only in this very specific scenario, which I've refined into minimal code:

<h:form id="mainForm">
    <p:tabView id="outer" dynamic="false">
        <p:tab id="outer1">
        </p:tab>
        <p:tab id="outer2">
            <p:tabView id="inner" dynamic="false">
                <p:tab id="inner1">
                    <p:treeTable value="#{someBB.root}" var="wrapper">
                        <p:column>
                            #{wrapper}
                        </p:column>
                    </p:treeTable>
                </p:tab>
                <p:tab>
                    <p:tab id="inner2">
                        <p:treeTable value="#{someBB.root}" var="wrapper">
                            <p:column>
                                #{wrapper}
                            </p:column>
                        </p:treeTable>
                    </p:tab>
                </p:tab>
            </p:tabView>
        </p:tab>
    </p:tabView>
</h:form>

The model is also minimal:

private TreeNode root;
{
    root = new DefaultTreeNode("root", null);
    TreeNode documents = new DefaultTreeNode("root", root);
    new DefaultTreeNode("node1", documents);
    new DefaultTreeNode("node2", documents);
}

public TreeNode getRoot(){
    return root;
}

So when I open the page, go to outer2 tab, I'm not able to expand the node in the inner1's treeTable. But when I switch to inner2, I can expand the nodes in that treeTable. And what is more strange is that when I switch back to inner1, I can expand the nodes there as well now. It is also correct if there are no nested tabviews.

Also when I remove the outer1 tab, the behavior is correct.

Also sharing the model doesn't affect this(I've tried having different model for each treeTable, but the behavior was the same).

Could there be some reason for this or is it a bug in PrimeFaces?

I use Primefaces 4.0

Answer 1

Some thoughts, but the answer to your question should be inside...

Well, first of all, your model has to be in a scope that allows it to keep its state between requests, otherwise you'll always have the absolute same tree (as in each request the tree model "root" will be generated again). Other important thing to notice is that you have to keep the root, your method should be something like this:

private TreeNode root;
{
    if (root != null)
        return root;

    root = new DefaultTreeNode("root", null);
    TreeNode documents = new DefaultTreeNode("root", root);
    new DefaultTreeNode("node1", documents);
    new DefaultTreeNode("node2", documents);
}

public TreeNode getRoot(){
    return root;
}

And you must remember to update the right tree (and I think keep just one tree updated is rather complex, imagine two!). And last, but not least, never use one model to both trees, you're messing everything, near impossible to makes things work properly in this situation. Try to use two models and keep the treemodel (root) with an apropriate scope (@ViewScoped or @SessionScoped in backing bean or @Session in a CDI bean).

I hope this can help you.