About the addCustomValueSetListener: This feature has many problems up to Vaadin version 13. It should work a lot better in Vaadin 14, which should be released soon (latest pre-release at the moment is 14.0.0.rc2).
About the addCustomValueSetListener: This feature has many problems up to Vaadin version 13. It should work a lot better in Vaadin 14, which should be released soon (latest pre-release at the moment is 14.0.0.rc2).