Widgetset problem with ImageScaler add on


I’m trying to use the current version of the ImageScaler addon in a Vaadin 7 project. I’ve used this addon previously. Now I get the following error:

Widgetset does not contain implementation for org.vaadin.peter.imagescaler.ImageScaler. Check its component connector’s @Connect mapping, widgetsets GWT module description file and re-compile your widgetset. In case you have downloaded a vaadin add-on package, you might want to refer to add-on instructions.

I copied the ImageScaler.jar to the WEB-INF/lib directory and manually recompiled the widgetset; if I remember correctly that’s all that was necessary to get it working in the past. My widgetset’s .gwt.xml file includes ImageScaler’s widgetset as

<inherits name="org.vaadin.peter.imagescaler.ImageScalerWidgetset" />

I tried creating a new project and including ImageScaler, and ran into the same behavior.

Would really appreciate some help with this, thanks in advance.

Matthew Fleming

The problem was that I needed a @Widgetset annotation on the main UI class. The widgetset has to be specified either in the web.xml or using the annotation. With Servlet 2.4 it has to be in web.xml but apparently with Servlet 3.0 an entry in web.xml is ignored, and the @Widgetset annotation is required. The documentation at, for example, https://vaadin.com/directory/help/using-vaadin-add-ons should probably be updated with this information. (Also, BTW, you might want to change the Eclipse plug-in so that “Suspend widgetset builds” is not checked by default.)

With Servlet 3.0, entries in web.xml override annotations but that happens on the level of whole servlet configurations, not individual parameters.