click event completes in hosted mode but not once deployed?

[darren]

Hi Everyone

In my web application i have some links that, when clicked are
supposed to:
- use an RPC to get some data from the server
- construct a new Panel
- insert the panel into the browser document

My solution seems to work as expected while in hosted mode, but not
once the application is deployed. I am using App Engine as a
server.

From what I can tell, the clickEvent does cause the asynchronous RPC
to fire, and the correct results are returned to the client. I see
the values I expect in FireBug's header view. For some reason the
clickEvent is not finishing as i would expect - the new panel is not
displayed.

There appear to be no errors on the server, as the logs remain
clean.

Any help on how to debug this would be much appreciated.

One possible problem area may be my use of java packages on the
client? I have my code in several packages:
com.app.client
com.app.client.model
com.app.client.util
etc....

I have not made any changes to my gwt.xml file, as I'm somewhat
confused about modules. With no changes here, the app is working as
expected in hosted mode, and the app does compile without error.

Thanks.

[darren]

ok, I found my problem.

In my client code, I had a try/catch expression that would ignore a
NullPointerException when a Map entry was attepted that didn't exist.
I replaced this, and my web app works as expected.

On a similar note, does anybody have any javascript debugging tips for
GWT? I have no way to set breakpoints / or otherwise observe the
javascript of my app. this is making debugging with alert statements
tedious.

[FKereki]

NullPointerExceptions can become JavaScriptExceptions when going from
hosted (development) mode to web (production) mode.

Check out http://code.google.com/p/google-web-toolkit-doc-1-6/wiki/DevGuideJavaCompatibility