Registering your own custom form builder

Until there's a better interface to register your own builders, you can do it this way.

If you create a form builder and use that (let's say your inherited this CustomFormBuilder from SimpleForm::FormBuilder), you'll need to "register" this builder in the rails.validations.js file.

If you don't register it, you'll get errors that has something to do with clientSideValidations.formBuilders[settings.type].

To register this CustomFormBuilder, you first need to add a new js file rails.validations.customFormBuilders.js and require it in your layout. Then simple add the following:

  // ...
    'SimpleForm::FormBuilder': {
      // ...
    },
    'CustomFormBuilder': {
      add: function(element, settings, message) {
        if (element.data('valid') !== false) {
          var wrapper = element.closest(settings.wrapper_tag);
          wrapper.addClass(settings.wrapper_error_class);
          var errorElement = $('<' + settings.error_tag + ' class="' + settings.error_class + '">' + message + '</' + settings.error_tag + '>');
          wrapper.append(errorElement);
        } else {
          element.parent().find(settings.error_tag + '.' + settings.error_class).text(message);
        }
      },
      remove: function(element, settings) {
        var wrapper = element.closest(settings.wrapper_tag + '.' + settings.wrapper_error_class);
        wrapper.removeClass(settings.wrapper_error_class);
        var errorElement = wrapper.find(settings.error_tag + '.' + settings.error_class);
        errorElement.remove();
      }
    },
    'Formtastic::SemanticFormBuilder': {
      // ...
    }
  // ...

In this particular case, it was exactly like the SimpleForm::FormBuilder entry, since CustomFormBuilder inherits from that and changed the resulting HTML only slightly. If your custom form builder is radically different, you will have to edit the js accordingly.