Evaluation of Vaadin Questions -


I have a few questions that either I missed or I just didn’t understand from the documentation that I have read:

  1. When applications are deployed as portlets, are the Ajax requests using the JSR-286 resource requests?
  2. If you have more than 2 portlets on the page, can they communicate with each other? Does the event-listener model work across portlets?
  3. How is performance versus a plain old GWT application?
  4. Are there any tutorials for a Maven - Spring based Vaadin portlet?



  1. Yes

  2. When using portlet events, communication between portlets on a page is possible but does result in full page refreshes due to how JSR-286 portlet request lifecycle works. Therefore, I would recommend using e.g.
    the ICEPush add-on
    and some other underlying communication channel if communicating between two Vaadin portlets for a smoother user experience.

  3. Depends on the application. There should not be many portlet-specific aspects to this, so earlier discussions about servlets mostly apply. There is a performance penalty when using Vaadin compared to carefully designed GWT applications (Vaadin is a layer on top of GWT), but in many cases it is not significant and the communication requirements of Vaadin can also be lower than those of a naively implemented GWT application. The initial download of a large GWT application can be significantly larger than that of Vaadin.

  4. Not that I am aware of, but maybe someone else knows of one. You could try to combine the information from some simple Maven-Spring-Portlet tutorial with a Vaadin-Spring tutorial, or a Vaadin-Portlet tutorial.

On Liferay, if you use custom widgets (from add-ons or written by you using GWT), widgetset compilation is probably best left to the
Vaadin Control Panel for Liferay