View Full Version : [CLOSED] Buffered rendered TreePanel setRootNode fails when the tree has been scrolled down

22 Jan 2013, 4:56 PM
Ext version tested:


Browser versions tested against:

Chrome 24.0.1312.52 m


I have a TreePanel configured with the BufferedRenderer plugin. After the tree is loaded, and after I scroll down the tree a couple of pages (via PageDown), if I try to reload the tree it fails with:

Unable to get value of the property 'insertSibling': object is null or undefined

in this function:

doAdd: function(records, index) {
var me = this,
nodes = me.bufferRender(records, index, true),
all = me.all,
count = all.getCount(),
i, l;

if (count === 0) {
for (i = 0, l = nodes.length; i < l; i++) {
} else if (index < count) {
if (index === 0) {
all.item(index).insertSibling(nodes, 'before', true);
} else {
all.item(index - 1).insertSibling(nodes, 'after', true);
} else {
all.last().insertSibling(nodes, 'after', true);

all.insert(index, nodes);
return nodes;

at this line:

all.item(index).insertSibling(nodes, 'before', true);

Steps to reproduce the problem:

Unzip the attached file in a directory where you can open app.html in your own web server of choice. Before you do that you might have to change app.html to point to the local directory where you keep extjs
Assuming you've successfuly opened the page in a browser, click on the Load Tree button. The data is loaded and alert message is displayed. Click the OK button.
Select the first node in the tree
Now press PageDown twice (now, this depends on how big the browser window is, you might have to scroll down more, basically enough to force the buffer to kick in)
Click again on the Load Tree button. This time the browser fails to reload the tree

The result that was expected:

The second click should reload the tree

The result that occurs instead:

The tree is not reloaded and the mask stays on. When debugging in IE9 and VS 2010 the page fails with the error described above

23 Jan 2013, 7:40 AM
Thanks for the report! I have opened a bug in our bug tracker.

10 Jun 2013, 12:54 AM

Any progress on this bug? I am having similar issues with BufferedRenderer.


23 Jul 2013, 5:19 AM
Reporting the same bug as well. Is there maybe a workaround for this at the premium forums?

23 Mar 2014, 11:16 PM
This seems to have been fixed at least in
The provided sample is working if anyone affected could please provide some feedback it would be very helpful. :)