Example of the newer define-widget form for defining Vaadin widgets

button_example_widget.scm

;; Example of a custom Vaadin widget in Scheme using Spil (github.com/mjvesa/spil)
;;
;; define-widget is a macro which takes the code and distributes it between the client and server
;; client part is uploaded to the browser
;; call-server invokes a server-rpc from the client side
;; server-rpc defines a server-rpc
(define-widget (button text listener)
  `((client
      (let ((button (element-new '(button ,text))))
       (append-to-root button)
       (js-set! button "onclick" (js-closure (lambda () (call-server 'click '()))))))
    (server-rpc (click ev)
                (,listener))))