Avoid installing 2 versions of Netbeans 6

Tonight I installed the latest OpenESB software (Build 20080303) and was rather confused as a lot has changed since I last used it back in October 2007. I found myself being rather unproductive so I decided to revert to an earlier version. So I downloaded Build 20080214 and installed it, but I did not uninstall the previous version. With the older version I repeatedly received exceptions on just about everything I clicked on. Many of my co-workers battle these issues everyday, but now I might have figured out why. For some reason, Netbeans just doesn't like being installed twice on the same system under the same folder (for me was /workspace/java/openesb). Under there I had 2 netbeans and 2 glassfish folders. Once I uninstalled everything and reinstalled the older version (Build 20080214) it worked perfectly.

So when you are receiving all those nasty exceptions every 5 seconds in Netbeans, make sure you only have one installed.

Challenges using Icefaces

I would just like to take a quick moment and inform anyone about Icefaces, and the challenges I have faced using it. Take it from my current experience (version 1.6.1 and 1.6.2) and the words of an Icefaces developer that since Icefaces "is a stateful technology......providing enhanced features for the user....but require server-side resources to do so." That last statement has been our recent struggle.

Unfortunately, on my current project we don't have the luxury of lots of server-side resources. It's disappointing to say we have to share a single server that is already running IIS; then we have to run Jboss and MS SQL on the same machine. Obviously this is not by choice and doesn't look to change in the near future.

It might be Icefaces never intended their framework to run in such a limited environment. But that really doesn't help me now. It would be great if they published information about minimum hardware requirements, especially if they are aware of performance issues. Equally important I am sure we have strayed away from best practices in using Icefaces.

Please don't ask me why we choose to use Icefaces in the first place (I wasn't with the group at the time). But I assume it was a lack of knowledge of how Icefaces works, and we weren't aware of the environment limitations. Either way, we are facing difficult challenges that are very frustrating.

For example, we recently had severe problems with an editable table which was sortable (much like an excel spreadsheet). When users clicked twice on the header to sort, the data appeared to be sent twice and some how our data got corrupted. Consequently we had to disable the ability to sort.

Also, based on my understanding of Icefaces, it appears that all clients maintain a constant connection with the server. I am assuming this is what the Icefaces developer above was referring to when he says Icefaces is a stateful technology. For some reason, I feel this constant connection would cause challenges for 50-100+ concurrent clients with limited server-side resources.

Hope it helps someone.

How to simulate onblur event for a Panel in Extjs

Here is a simple trick in Extjs I borrowed from Ext.layout.BorderLayout that simulates listening for the onblur event of an Ext.Panel. This trick is necessary because unfortunately Ext.Panel does not natively support registering for the onblur event (or at least I don't know how). We typically use this trick when we show a Panel and want to remove it when the user clicks off, or to state it differently, when the Panel looses focus. This is very similar to how menus work.

Step 1: Register for mousedown event

this.panel.show();
Ext.getDoc().on("mousedown", this.handleDocMouseDown, this);

First, we show the panel. Here it is assumed this was created previously. Second, we use Ext.getDoc() to return the current HTML document object, and then we register for the mousedown event. The second parameter, this.handleDocMouseDown, is our function we want called when this event is fired. Notice that we register for the mousedown event as opposed to the click event. This is intentional because listening for the click event will actually call this.handleDocMouseDown before your ready because a click involves both mousedown and mouseup.

Step 2: Handle the event

handleDocMouseDown : function(e) {
if (!e.within(this.panel.getEl())) {
   this.panel.destroy();
   Ext.getDoc().un("mousedown", this.handleDocMouseDown, this);
}
}

In our second step we first check to make sure the user didn't click anywhere in the Panel that was just displayed. If it wasn't then we destroy the panel and unregister the mousedown event.