How would a helper method for this UI code look like?

Question

I'd like to refactor some UI code.

I have a HTML form (here: written in a Java GUI called Wicket) where I put some links (anchor tags). Instead of repeating the code over and over again, I want to create a new elegant helper method.

String type = "", id = ""; 
Form form, Service service;

form.add(new Widget("createLink", form) { // the same for read, update, delete
    private static final long serialVersionUID = 1L;
    @Override
    public void onSubmit() {
        try {
            service.create(type, id);  // the same for service.read / update / delete
            info("Specific message for create, read, update, delete");
        } catch (DataAccessException e) {
            error(ExceptionUtils.getRootCauseMessage(e));
        }
    }
});
form.add(new Widget("readLink", form) {
    // ... service.read(...); info("... read ...");
});
form.add(new Widget("updateLink", form) {
    // ... service.update(...); info("... update ...");
});

As you've already guessed, I would like to have sth. like

form.add(createLink(htmlId, form, type, id, message, ?));

I'd like to avoid create an extra class for that. But Lambdas would be fine.

What would be the best approach? And how is the pattern called?

Thanks.

Answer 1

For ? you can use java.util.function.Consumer:

private void createLink(String htmlId, Form<?> form, String type, String id, String feedbackMessage, Runnable _onSubmit) {
    return new Widget(htmlId, form) {
      private static final long serialVersionUID = 1L;

      @Override
      public void onSubmit() {
        try {
          _onSubmit();
          info(feedbackMessage);
        } catch (DataAccessException e) {
          error(ExceptionUtils.getRootCauseMessage(e));
        }
      }
    }
}

Usage:

form.add(createLink("createLink", form, type, id, createMessage, () -> {
  service.create(type, id);
}));