Integrating stepper into the Generic UI

I integrated the Stepper Vaadin component into my project as described on
It works fine when used by manual insertion into an xml form descriptor or creation by controller code. But there is no Stepper component in UI designer palette and there are no specific stepper properties on the Properties tab.
I found 2 lines in the studio log:
2018-05-24 13:18:38,822 INFO [] Model class for stepper not found
2018-05-24 13:24:20,406 INFO [com.vaadin.server.VaadinServlet] Requested resource [/VAADIN/ace/worker-xml.js] not found from filesystem or through class loader. Add widgetset and/or theme JAR to your classpath or add files to WebContent/VAADIN folder.

Maybe I missed something when integrating the stepper? (2.3 KB)

Hello, @evgenypopov!

Did you complete the steps from chapter “Support for Custom Visual Components in CUBA Studio”?

No, I didn’t.
But now, after this step is completed, I get the error in the studio log when opening my form:

groovy.lang.MissingMethodException: No signature of method: static is applicable for argument types: (java.lang.String) values: [msg://flashmobMaxVolunteer]
	at groovy.lang.MetaClassImpl.invokeStaticMissingMethod(
	at groovy.lang.MetaClassImpl.invokeStaticMethod(

upd1: Property “caption” of the component Stepper is unavailable to set/change.

upd2: After removal of the caption option from the stepper component in the xml descriptor I got another error:

    Validation error
    Invocation of method selectedTabChange in$1 failed.

There is a TabSheet component indeed on my form but the stepper do not lay on it.

Hi, Evgeny

Regarding groovy.lang.MissingMethodException.
There is a bug in Studio, so it can’t handle caption property for custom components. It will be fixed in the next maintenance release. See YouTrack issue.
As a temporary workaround you can set caption in controller code.

Unfortunately I can’t reproduce your second issue. Could you please provide any additional information?
Best option is a test project, where the problem could be reproduced.

Thanks for reporting the problems,

Unfortunately I have no enough time to create a test project. Suppose that it linked to the 1st.
Thank you for support, I’ll wait for the fix.

Hi again,
One of my colleague pulled our changed project from git repository and built it, but got an an error text instead of the Stepper component on his form:


The error is present on his workplace only. What should he do to eliminate it?


Did he rebuild WidgetSet after pulling those changes?
Try to execute gradle clean assemble tasks.

Clean & assemble gave no results. The other members of our team didn’t make any special actions but have working applications.
He installed the latest version of CUBA Studio and even cleared studio cache but no results again.

Could you provide content of the AppWidgetSet.gwt.xml file on his machine?

Also OS and CUBA Platform versions can be helpful.

The AppWidgetSet.gwt.xml is identical on all our machines:

<?xml version="1.0" encoding="UTF-8" standalone="no"?>
    <inherits name="com.haulmont.cuba.web.toolkit.ui.WidgetSet"/>
    <inherits name="com.haulmont.charts.web.toolkit.ui.ChartsWidgetSet"/>
    <inherits name="com.vaadin.sebastian.indeterminatecheckbox.IndeterminateCheckboxWidgetSet"/>
    <inherits name="org.vaadin.risto.stepper.widgetset.StepperWidgetset"/>

OS Windows 7 pro, CUBA platform version 6.8.4

\deploy\tomcat\webapps\app\VAADIN\widgetsets\\stepper folder exist?

Try to undeploy project and then start.