value * * @link http://www.sitemaps.org/protocol.php Sitemaps XML format */ class Changefreq extends AbstractValidator { /** * 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 => "The input 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 * * @param string $value value to validate * @return bool */ public function isValid($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; } }