India Meetup Group Q&A Session

Join the
India Meetup Group
's Q&A Session on Vaadin with Matti Tahvonen and Fredrik Rönnlund from the Vaadin team answering your questions. For further questions post them below in this thread.


India Q&A session starting in 5 minutes. Join live here and post your questions below.

We (TejaSoft) wishes to be a execution (implementation) partner to Vaadin. As we are small firm, how does Vaadin enguage with small companies. Do they help in customers aqusation or leads support.

We have been using Vaading when it was itmill since 7 years now… but find very difficult to get the clients reach us.

How to invalidate HttpSession on logoff,

VaadinService.getCurrentRequest().getWrappedSession().invalidate(); This statement throws exception with Vaadin-7, push enabled, Tomcat7.

1 Can push notification be used for refreshing data changes on UI(dynamically)
2. Required more details on controlling scroll on layouts and components
3. Compilation of widgetset time is huge, can we reduce the time during development process

I have 2 questions:

  1. How does one approach Test Driven Development in Vaadin. Do you recommend going about implementing the UI classes with a TDD approach?
  2. How does and Spring integration with Vaadin development. Is there an example project out there that I can go through which has Vaadin Spring + hibernate?

How to handle vaadin session in multi-cluster environment?


How can we make Autorefresh for the view page that extends VerticalLayout for every n seconds

If application is with slow performance, how to evaluate/find the reason in vaadin? Can you suggest any tool for the same

Which pakagmanager is better for vaadin applications .
and why?

We are facing problem in writing the selinum scripts to do regression test, apart from Vaadin TestBench

I have one issue in using Lazy query container, using this container, the list
is loaded starting time itself before execute the query for getting list method in this case
method,How can we get the Size of the list before execute the query.
can you please give any solution on this?


I want a conformation from client side before closing the session, what is the best way to handle it in Vaadin7.

Does Vaadin provie any API within to implement RBAC/Access control.

Are there any plans to setup support center in India ? If so,When?

Who is using VAADIN in India? If so, any large enterprise being used?

Which pakagmanager is better for vaadin applications .
and why?

How can i clone the chart configuration object.

If i apply or remove the style to vaadin Donut chart it is repainting .how can i stop it?

Hello Team,

It would be great if you could come up with set of tutorials with respect to developing pure Client Side Widget and integrating the same with Vaadin Backend. Though we have a wiki page it is not that exhaustive.
What I’m looking at is a good lauching pad to start writing a Client side Widget.

Can you please look in to it.


What precautions should be take if we change the existing component code as the new version of vaadin is released. Do you have any plugin or extenstion architecture like it is in Liferay

  1. Push notification from where is the question? If you have @Push annotated ui, you can just modify your uis from any other thread and the change will happen automatically for the client. Similarly if you have enabled “polling” as well. Be sure to change your UIs sychronously. Easiest and safest method is to use UI.access(Runnable) method.
  2. Panels (including splitpanel) have scrollable content by default. Using them is the easiest method, but you can also do “overflow:auto” hacks with CSS.
  3. Couple of tricks: You should only build your widgetset during clean build and ofter version updates. Widgetset building can also be split to separate module in multimodule maven project to avoid non relevant gwt compilations. During extension development you’ll naturally need to do this, but there you can use devmode/superdevmode. Updating to latest Vaadin version will also cut down the compilation time dramatically. GWT has developed a lot on this field lately.