root/trunk/lib/validator/sfValidatorTags.class.php

<?php
/**
 * This validators validates tags string
 *
 */
class sfValidatorTags extends sfValidatorBase
{

  /**
   * Configures the validator
   *
   * @param unknown_type $options
   * @param unknown_type $messages
   */
  public function configure($options = array(), $messages = array())
  {
    $this->addOption('separator', ',');
    $this->setMessage('invalid', 'Looks like your tags should be separated by the "%separator%" char');
  }

  /**
   * Apply validator
   *
   * @param  mixed $value
   * @return mixed
   */
  public function doClean($value)
  {
    if (' ' === $this->getOption('separator'))
    {
      return $value;
    }

    $words = str_word_count($value);
    $seps = substr_count($value, $this->getOption('separator'));

    if ($seps < $words / 2)
    {
      throw new sfValidatorError($this, 'invalid', array('separator' => $this->getOption('separator')));
    }

    return $value;
  }

}