Hello
I am a new user of Vaadin, starting by making a project in Eclipse, pasting the code of the
Five Minute Tutorial
and hacking it a bit.
I had to hunt down the information that I had to add
?restartApplication
at the end of the Tomcat URL to see my changes (eg. label renaming).
I also had a deprecation warning on the SplitPanel component, I suggest to update the tutorials using it to switch to HorizontalSplitPanel or the vertical one.
While testing the application, I could test the nice exception reporting when I clicked on the + button… It was the opportunity to debug the application, which is a pleasure to do (easy and efficient).
I found out that in the handler of initContactAddRemoveButtons, we call addItemAt(0), then we do getItem(id). But I found out that the latter operation can return null! Hence the exception.
Why do we get null? Because I clicked the button while filtering the list! So the empty item was automatically removed from the view, and cannot be found back…
I just avoided to use the item if null, but it isn’t a satisfying solution as it remains empty and out of view. We should at least be able to change it to John Doe, but as a newbie, I don’t know yet if it can be done, and how.
So I suggest to update this code to handle this case (or just disable the + button when filtering the list…).
So far, I find Vaadin very intuitive to use, I really like it! I must do a quick prototype with it, and I believe I will get it done much faster than if I had to use SmartGWT or similar…