how to replace a specific widget by another for all generated forms in symfony

Configuration.class.php

<?php

class xxxConfiguration extends sfXxxConfiguration
{
    public function setup()
    {
 
        $this->dispatcher->connect('command.filter_options', array($this, 'filterCommandOptions'));
    }
 
    /**
     * Filters command options.
     *
     * @param   sfEvent $event
     * @param   array   $options
     *
     * @return  array
     */
    public function filterCommandOptions(sfEvent $event, $options) {

        // force generator class when running build-forms task
        if ('sfDoctrineBuildFormsTask' === get_class($event->getSubject()))
        {
          $options = array('--generator-class=myFormGenerator');
        }
        return $options;
    }
}

myFormGenerator.class.php

<?php

/**
 * @author johnwards
 * @link http://stackoverflow.com/questions/2881379/symfony-forms-how-to-change-default-widget-for-form-generation
 */
class myFormGenerator extends sfDoctrineFormGenerator
{

  public function getWidgetClassForColumn($column)
  { 
    switch ($column->getDoctrineType())
    {
      case 'date':
        return 'sfWidgetFormDateJQueryUI';
        break;
      default:
        return parent::getWidgetClassForColumn($column);
    }
  }
  public function getWidgetOptionsForColumn($column)
  {
    switch ($column->getDoctrineType())
    {
      case 'date':
        return "array('image'=>'/images/icones/calendrier.gif')";
    break;
      default:
        return parent::getWidgetOptionsForColumn($column);
    }
  }
  
}