How do you show a processing image while Vaadin is bootstrapping?

This has probably been asked elsewhere but I was unable to find the correct search criteria.

When you first hit a Vaadin UI there is a blank page shown. How can you provide some user feedback during this time to let them know that it is not simply a dead link.

In other words, while the Vaadin app/UI is loading how can you show some kind of visual feedback (processing animation / please wait to load text) to the user.

Thanks in advance }>

A good question. I could not remember myself exactly how it was done so I had a look and wrote
a tutorial
about it at the same time. I also discovered a bug related to this in 7.0 which I hope we can get fixed already for 7.1

Thanks for the quick response Artur.

I am working with 7.1 beta.
If you have a simple Vaadin application, does the default load indicator require some minimum delay before it activates? I currently do not see any load indicator, just a blank page prior to the application loading.

Is there a setting to enable/disable the default load indicator?

Thanks again.

Because of the default loading indicator is never shown

Got it. Thank you Artur.

Hi Artur,

I work with Vaadin 7.1.1 and the problem seems to be not fixed I think or maybe it’s another issue.
I have a Vaadin application (in a Liferay Portlet) that take 3-4 secondes to be loaded and before showing the application I have a blank page with no loading indicator.
After my 3-4 seconds the application appear with a very fast loading indicator (less than 1 second).

The problem discusses has been fixed in Vaadin 7.1.1, that’s right? So why I can’t have this loading indicator during the blank page, is it an other bug?

Thanks in advance,

The loading indicators are only shown after the client side of the application has been loaded in the browser and started (but before application view content has been loaded by them from the server). The bug mentioned here was that the initial load indicator was not shown immediately after the client side module (widgetset) was started.

What I suspect happens in your case with the portal is that getting to the point where the portlet bootstrap javascript has been loaded takes a while. I can’t say based on this information where the delays are, though - or even whether they are on the server side or on the client side.