text: <?php
  /**
   * Zend Framework
   *
   * LICENSE
   *
   * This source file is subject to the new BSD license that is bundled
   * with this package in the file LICENSE.txt.
   * It is also available through the world-wide-web at this URL:
   * http://framework.zend.com/license/new-bsd
   * If you did not receive a copy of the license and are unable to
   * obtain it through the world-wide-web, please send an email
   * to license@zend.com so we can send you a copy immediately.
   *
   * @category   Zend
   * @package    Zend_Validate
   * @subpackage Sitemap
   * @copyright  Copyright (c) 2005-2015 Zend Technologies USA Inc. (http://www.zend.com)
   * @license    http://framework.zend.com/license/new-bsd     New BSD License
   * @version    $Id$
   */
  
  /**
   * @see Zend_Validate_Abstract
   */
  require_once 'Zend/Validate/Abstract.php';
  
  /**
   * Validates whether a given value is valid as a sitemap <changefreq> value
   *
   * @link       http://www.sitemaps.org/protocol.php Sitemaps XML format
   *
   * @category   Zend
   * @package    Zend_Validate
   * @subpackage Sitemap
   * @copyright  Copyright (c) 2005-2015 Zend Technologies USA Inc. (http://www.zend.com)
   * @license    http://framework.zend.com/license/new-bsd     New BSD License
   */
  class Zend_Validate_Sitemap_Changefreq extends Zend_Validate_Abstract
  {
      /**
       * Validation key for not valid
       *
       */
      const NOT_VALID = 'sitemapChangefreqNotValid';
      const INVALID   = 'sitemapChangefreqInvalid';
  
      /**
       * Validation failure message template definitions
       *
       * @var array
       */
      protected $_messageTemplates = array(
          self::NOT_VALID => "'%value%' is not a valid sitemap changefreq",
          self::INVALID   => "Invalid type given. String expected",
      );
  
      /**
       * Valid change frequencies
       *
       * @var array
       */
      protected $_changeFreqs = array(
          'always',  'hourly', 'daily', 'weekly',
          'monthly', 'yearly', 'never'
      );
  
      /**
       * Validates if a string is valid as a sitemap changefreq
       *
       * @link http://www.sitemaps.org/protocol.php#changefreqdef <changefreq>
       *
       * @param  string  $value  value to validate
       * @return boolean
       */
      public function isValid($value)
      {
          if (!is_string($value)) {
              $this->_error(self::INVALID);
              return false;
          }
  
          $this->_setValue($value);
          if (!is_string($value)) {
              return false;
          }
  
          if (!in_array($value, $this->_changeFreqs, true)) {
              $this->_error(self::NOT_VALID);
              return false;
          }
  
          return true;
      }
  }
  