Felder zu FormContainer per Event-Listener hinzufügen

protected function createForm()
    {
        parent::createForm();

        $this->form->appendChild(
            FormContainer::create('data')
                ->label('wcf.global.form.data')
                ->appendChildren([
                    TextFormField::create('todoName')
                        ->label('todolist.column.todoName')
                        ->required()
                        ->autoFocus()
                        ->maximumLength(255),
                        
                    MultilineTextFormField::create('description')
                        ->label('todolist.column.description')
                        ->required()
                        ->maximumLength(8192),
                        
                    BooleanFormField::create('done')
                        ->label('todolist.column.done')
                        ->value(false),
                ])
        );
    }

class TodoAddEventListener implements IParameterizedEventListener {

    /**
     * @inheritDoc
     */
    public function execute($eventObj, $className, $eventName, array &$parameters) {
        $this->$eventName($eventObj);
    }

    /**
     * @inheritDoc
     */
    protected function createForm(TodoAddForm $eventObj)
    {
        $eventObj->form->appendChild(
            FormContainer::create('data')
                ->label('wcf.global.form.data')
                ->appendChildren([
                    BooleanFormField::create('enableComments')
                        ->label('todolist.comments.enable')
                        ->description('todolist.comments.enable.description')
                        ->value(true),
                ])
        );
    }
}