Does TreeTable support lazy loading?

[Naresh Bhatia <NB...@sapient.com>]

Does TreeTable support lazy loading? I would like to display a very
large tree and want to lazy load the children when the user expands a
parent node. After reading the documentation I thought that the
RowDisclosureEvent could be used for this, but I don't readily see how.
This is what I have done so far:

// Set the treeModel and rowDisclosureListener for the tree table
<tr:treeTable var="node" value="#{treeTableBean.treeModel}"
    rowDisclosureListener="#{treeTableBean.processRowDisclosureEvent}">
    ...
</tr:treeTable>

// Here's the bean method that returns the tree model
// ************ Just return the root node ***********
public TreeModel getTreeModel() {
    if (treeModel == null)
	{
        TreeNodeVO root = getTreeService().getTreeNode("CORP");
        treeModel = new ChildPropertyTreeModel(root, "children");
	}
}

At this point I see a TreeTable on my page with just the root node, but
no arrow to expand it. So here are my questions:

1) Since the root node cannot be expanded, the rowDisclosureListener
will not be called. Even if it is called, how can I use the event to
lazily connect the children to the root node? How does the event tell me
what to fetch next and where to put this information?
2) Currently I have my bean in request scope. Does TreeTable, especially
with lazy loading, require the bean to be in the session scope?

Thanks for your help.

Naresh Bhatia

RE: Does TreeTable support lazy loading?

[Naresh Bhatia <NB...@sapient.com>]

I would really appreciate if someone could give me a helping hand on
this question. I have to deliver a proof-of-concept by Monday, so even
small hints would help me tremendously. Please see below for details.

Again, thanks so much for your help.

Naresh Bhatia


-----Original Message-----
From: Naresh Bhatia [mailto:NBhatia@sapient.com] 
Sent: Thursday, September 21, 2006 5:53 PM
To: adffaces-user@incubator.apache.org
Subject: Does TreeTable support lazy loading?

Does TreeTable support lazy loading? I would like to display a very
large tree and want to lazy load the children when the user expands a
parent node. After reading the documentation I thought that the
RowDisclosureEvent could be used for this, but I don't readily see how.
This is what I have done so far:

// Set the treeModel and rowDisclosureListener for the tree table
<tr:treeTable var="node" value="#{treeTableBean.treeModel}"
    rowDisclosureListener="#{treeTableBean.processRowDisclosureEvent}">
    ...
</tr:treeTable>

// Here's the bean method that returns the tree model
// ************ Just return the root node ***********
public TreeModel getTreeModel() {
    if (treeModel == null)
	{
        TreeNodeVO root = getTreeService().getTreeNode("CORP");
        treeModel = new ChildPropertyTreeModel(root, "children");
	}
}

At this point I see a TreeTable on my page with just the root node, but
no arrow to expand it. So here are my questions:

1) Since the root node cannot be expanded, the rowDisclosureListener
will not be called. Even if it is called, how can I use the event to
lazily connect the children to the root node? How does the event tell me
what to fetch next and where to put this information?
2) Currently I have my bean in request scope. Does TreeTable, especially
with lazy loading, require the bean to be in the session scope?

Thanks for your help.

Naresh Bhatia