The Validator class provides static access to commonly used data validation logic. These common routines cover HTML form input data such as phone and credit card numbers, dates and postal codes, but also include general checks for regular expressions and booleans and numericality.

General data checking is done by using Validator statically. Rules can be specified as a parameter to the rule() method or accessed directly via the is[RuleName]() method name convention:

use lithium\util\Validator;

// The following are equivalent:
Validator::rule('email', '');  // true
Validator::isEmail('');     // false

Data can also be validated against multiple rules, each having their own associated error message. The rule structure is array-based and hierarchical based on rule names and messages. Responses match the keys present in the $data parameter of check() up with an array of rules which they violate.

See the `check()` method for more information an multi-value datasets. Custom validation rules
can also be added to `Validator` at runtime. These can either take the form of regular expression
strings or functions supplied to the `add()` method.

### Rules

The `Validator` class includes a series of commonly-used rules by default, any of which may be
used in calls to `rule()` or `check()`, or called directly as a method. Additionally, many rules
have a variety of different _formats_ in which they may be specified. The following is the list
of the built-in rules, but keep in mind that none of them are hard-coded. Any rule may be
overridden by adding a new rule of the same name using the `add()` method.

- `notEmpty`: Checks that a string contains at least one non-whitespace character.

- `alphaNumeric`: Checks that a string contains only integer or letters.

- `lengthBetween`: Checks that a string length is within a specified range. Spaces are included
  in the character count. The available options are `'min'` and `'max'`, which designate the
  minimum and maximum length of the string.

- `blank`: Checks that a field is left blank **OR** only whitespace characters are present in its
  value. Whitespace characters include spaces, tabs, carriage returns and newlines.

- `creditCard`: Checks that a value is a valid credit card number. This rule is divided into a
  series of formats: `'amex'`, `'bankcard'`, `'diners'`, `'disc'`, `'electron'`, `'enroute'`,
  `'jcb'`, `'maestro'`, `'mc'`, `'solo'`, `'switch'`, `'visa'`, `'voyager'`, `'fast'`. If no
  format value is specified, the value defaults to `'any'`, which will validate the value if
  _any_ of the available formats match. You can also use the `'fast'` format, which does a
  high-speed, low-fidelity check to ensure that the value looks like a real credit card number.
  This rule includes one option, `'deep'`, which (if set to `true`) validates the value using the
  [Luhn algorithm]( if the format validation is
  successful. See the `luhn` validator below for more details.

- `date`: Checks that a value is a valid date that complies with one or more formats. Also
  validates leap years. Possible formats are `'dmy'` (27-12-2010 or 27-12-10 separators can be a
  space, period, dash, forward slash), `'mdy'` (12-27-2010 or 12-27-10 separators can be a space,
  period, dash, forward slash), `'ymd'` (2010-12-27 or 10-12-27 separators can be a space,
  period, dash, forward slash), `'dMy'` (27 December 2010 or 27 Dec 2010), `'Mdy'` (December 27,
  2010 or Dec 27, 2010 comma is optional), `'My'` (December 2010 or Dec 2010) or `'my'` (12/2010
  separators can be a space, period, dash, forward slash).

- `time`: Checks that a value is a valid time. Validates time as 24hr (HH:MM) or am/pm
  ([ H]H:MM[a|p]m). Does not allow / validate seconds.

- `boolean`: Checks that the value is or looks like a boolean value. The following types of
  values are interpreted as boolean and will pass the check.
  - boolean (`true`, `false`, `'true'`, `'false'`)
  - boolean number (`1`, `0`, `'1'`, `'0'`)
  - boolean text string (`'on'`, `'off'`, `'yes'`, `'no'`)

- `decimal`: Checks that a value is a valid decimal. Takes one option, `'precision'`, which is
  an optional integer value defining the level of precision the decimal number must match.

- `email`: Checks that a value is (probably) a valid email address. The subject of validating
  an actual email address is complicated and problematic. A regular expression that correctly
  validates addresses against [RFC 5322]( would be several
  pages long, with the drawback of being unable to keep up as new top-level domains are added.
  Instead, this validator uses PHP's internal input filtering API to check the format, and
  provides an option, `'deep'` ( _boolean_) which, if set to `true`, will validate that the email
  address' domain contains a valid MX record. Keep in mind, this is just one of the many ways to
  validate an email address in the overall context of an application. For other ideas or
  examples, [ask Sean](

- `ip`: Validates a string as a valid IPv4 or IPv6 address.

- `money`: Checks that a value is a valid monetary amount. This rule has two formats, `'right'`
  and `'left'`, which indicates which side the monetary symbol (i.e. $) appears on.

- `numeric`: Checks that a value is numeric.

- `phone`: Check that a value is a valid phone number, non-locale-specific phone number.

- `postalCode`: Checks that a given value is a valid US postal code.

- `inRange`: Checks that a numeric value is within a specified range. This value has two options,
   `'upper'` and `'lower'`, which specify the boundary of the value.

- `url`: Checks that a value is a valid URL according to
  [RFC 2395]( Uses PHP's filter API, and accepts any
  options accepted for
  [the validation URL filter](

- `luhn`: Checks that a value is a valid credit card number according to the
  [Luhn algorithm]( (See also: the `creditCard`

- `inList`: Checks that a value is in a pre-defined list of values. This validator accepts one
  option, `'list'`, which is an array containing acceptable values.

- `regex`: Checks that a value appears to be a valid regular expression, possibly
  containing PCRE-compatible options flags.

- `uuid`: Checks that a value is a valid UUID.

### UTF-8 encoded input strings

All rules operating on strings have been created with the possibility of
UTF-8 encoded input in mind. A default PHP binary and an enabled Lithium
g11n bootstrap will make these rules work correctly in any case. Should you
ever experience odd behavior following paragraph with implementation
details might help you to track down the cause.

The rules `alphaNumeric` and `money` rely on additional functionality of
PCRE to validate UTF-8 encoded strings. As no PCRE feature detection is
done, having this feature enabled in PCRE isn't optional. Please ensure
you've got PCRE compiled with UTF-8 support.


class Validator extends \lithium\core\StaticObject {

	 * An array of validation rules.  May contain a single regular expression, an array of regular
	 * expressions (where the array keys define various possible 'formats' of the same rule), or a
	 * closure which accepts a value to be validated, and an array of options, and returns a
	 * boolean value, indicating whether the validation succeeded or failed.
	 * @var array
	 * @see lithium\util\Validator::add()
	 * @see lithium\util\Validator::rule()
	protected static $_rules = array();

	 * Default options used when defining a new validator rule. Each key contains method-specific
	 * options that should always be applied, or options that should be applied to all rules in the
	 * `'defaults'` key.
	 * @see lithium\util\Validator::add()
	 * @see lithium\util\Validator::rule()
	 * @var array
	protected static $_options = array(
		'defaults' => array('contains' => true)

	 * Initializes the list of default validation rules.
	public static function reset() {
		$alnum = '[A-Fa-f0-9]';
		$class = get_called_class();
		static::$_methodFilters[$class] = array();

		static::$_rules = array(
			'alphaNumeric' => '/^[\p{Ll}\p{Lm}\p{Lo}\p{Lt}\p{Lu}\p{Nd}]+$/mu',
			'blank'        => '/[^\\s]/',
			'creditCard'   => array(
				'amex'     => '/^3[4|7]\\d{13}$/',
				'bankcard' => '/^56(10\\d\\d|022[1-5])\\d{10}$/',
				'diners'   => '/^(?:3(0[0-5]|[68]\\d)\\d{11})|(?:5[1-5]\\d{14})$/',
				'disc'     => '/^(?:6011|650\\d)\\d{12}$/',
				'electron' => '/^(?:417500|4917\\d{2}|4913\\d{2})\\d{10}$/',
				'enroute'  => '/^2(?:014|149)\\d{11}$/',
				'jcb'      => '/^(3\\d{4}|2100|1800)\\d{11}$/',
				'maestro'  => '/^(?:5020|6\\d{3})\\d{12}$/',
				'mc'       => '/^5[1-5]\\d{14}$/',
				'solo'     => '/^(6334[5-9][0-9]|6767[0-9]{2})\\d{10}(\\d{2,3})?$/',
				'switch'   => '/^(?:49(03(0[2-9]|3[5-9])|11(0[1-2]|7[4-9]|8[1-2])|36[0-9]{2})' .
				              '\\d{10}(\\d{2,3})?)|(?:564182\\d{10}(\\d{2,3})?)|(6(3(33[0-4]' .
				'visa'     => '/^4\\d{12}(\\d{3})?$/',
				'voyager'  => '/^8699[0-9]{11}$/',
				'fast'     => '/^(?:4[0-9]{12}(?:[0-9]{3})?|5[1-5][0-9]{14}|6011[0-9]{12}|3' .
			'date'         => array(
				'dmy'      => '%^(?:(?:31(\\/|-|\\.|\\x20)(?:0?[13578]|1[02]))\\1|(?:(?:29|30)' .
				              '(\\/|-|\\.|\\x20)(?:0?[1,3-9]|1[0-2])\\2))(?:(?:1[6-9]|[2-9]\\d)?' .
				              '\\d{2})$|^(?:29(\\/|-|\\.|\\x20)0?2\\3(?:(?:(?:1[6-9]|[2-9]\\d)?' .
				              '(?:0[48]|[2468][048]|[13579][26])|(?:(?:16|[2468][048]|[3579][26])' .
				              '00))))$|^(?:0?[1-9]|1\\d|2[0-8])(\\/|-|\\.|\\x20)(?:(?:0?[1-9])|' .
				'mdy'      => '%^(?:(?:(?:0?[13578]|1[02])(\\/|-|\\.|\\x20)31)\\1|(?:(?:0?[13-9]|' .
				              '1[0-2])(\\/|-|\\.|\\x20)(?:29|30)\\2))(?:(?:1[6-9]|[2-9]\\d)?\\d' .
				              '{2})$|^(?:0?2(\\/|-|\\.|\\x20)29\\3(?:(?:(?:1[6-9]|[2-9]\\d)?' .
				              '(?:0[48]|[2468][048]|[13579][26])|(?:(?:16|[2468][048]|[3579][26])' .
				              '00))))$|^(?:(?:0?[1-9])|(?:1[0-2]))(\\/|-|\\.|\\x20)(?:0?[1-9]|1' .
				'ymd'      => '%^(?:(?:(?:(?:(?:1[6-9]|[2-9]\\d)?(?:0[48]|[2468][048]|[13579]' .
				              '[26])|(?:(?:16|[2468][048]|[3579][26])00)))(\\/|-|\\.|\\x20)' .
				              '(?:0?2\\1(?:29)))|(?:(?:(?:1[6-9]|[2-9]\\d)?\\d{2})(\\/|-|\\.|' .
				              '\\x20)(?:(?:(?:0?[13578]|1[02])\\2(?:31))|(?:(?:0?[1,3-9]|1[0-2])' .
				              '\\2(29|30))|(?:(?:0?[1-9])|(?:1[0-2]))\\2(?:0?[1-9]|1\\d|2[0-8]' .
				'dMy'      => '/^((31(?!\\ (Feb(ruary)?|Apr(il)?|June?|(Sep(?=\\b|t)t?|Nov)' .
				              '(ember)?)))|((30|29)(?!\\ Feb(ruary)?))|(29(?=\\ Feb(ruary)?\\ ' .
				              '(((1[6-9]|[2-9]\\d)(0[48]|[2468][048]|[13579][26])|((16|[2468]' .
				              '[048]|[3579][26])00)))))|(0?[1-9])|1\\d|2[0-8])\\ (Jan(uary)?|' .
				              'Feb(ruary)?|Ma(r(ch)?|y)|Apr(il)?|Ju((ly?)|(ne?))|Aug(ust)?|' .
				              'Oct(ober)?|(Sep(?=\\b|t)t?|Nov|Dec)(ember)?)\\ ((1[6-9]|[2-9]' .
				'Mdy'      => '/^(?:(((Jan(uary)?|Ma(r(ch)?|y)|Jul(y)?|Aug(ust)?|Oct(ober)?' .
				              '|Dec(ember)?)\\ 31)|((Jan(uary)?|Ma(r(ch)?|y)|Apr(il)?|Ju((ly?)' .
				              '|(ne?))|Aug(ust)?|Oct(ober)?|(Sept|Nov|Dec)(ember)?)\\ (0?[1-9]' .
				              '|([12]\\d)|30))|(Feb(ruary)?\\ (0?[1-9]|1\\d|2[0-8]|(29(?=,?\\ ' .
				              '((1[6-9]|[2-9]\\d)(0[48]|[2468][048]|[13579][26])|((16|[2468]' .
				              '[048]|[3579][26])00)))))))\\,?\\ ((1[6-9]|[2-9]\\d)\\d{2}))$/',
				'My'       => '%^(Jan(uary)?|Feb(ruary)?|Ma(r(ch)?|y)|Apr(il)?|Ju((ly?)|(ne?))|' .
				              'Aug(ust)?|Oct(ober)?|(Sep(?=\\b|t)t?|Nov|Dec)(ember)?)\\ ((1[6-9]' .
				'my'       => '%^(0?[1-9]|1[012])([- /.])((1[6-9])|([2-9]\\d)\\d{2})$%'
			'ip' => function($value, $format = null, array $options = array()) {
				$options += array('flags' => array());
				return (boolean) filter_var($value, FILTER_VALIDATE_IP, $options);
			'money'        => array(
				'right'    => '/^(?!0,?\d)(?:\d{1,3}(?:([, .])\d{3})?(?:\1\d{3})*|(?:\d+))' .
				'left'     => '/^(?!\x{00a2})\p{Sc}?(?!0,?\d)(?:\d{1,3}(?:([, .])\d{3})?' .
			'notEmpty'     => '/[^\s]+/m',
			'phone'        => '/^\+?[0-9\(\)\-]{10,20}$/',
			'postalCode'   => '/(^|\A\b)[A-Z0-9\s\-]{5,}($|\b\z)/i',
			'regex'        => '/^(?:([^[:alpha:]\\\\{<\[\(])(.+)(?:\1))|(?:{(.+)})|(?:<(.+)>)|' .
			'time'         => '%^((0?[1-9]|1[012])(:[0-5]\d){0,2}([AP]M|[ap]m))$|^([01]\d|2[0-3])' .
			'boolean'      => function($value) {
				$bool = is_bool($value);
				$filter = filter_var($value, FILTER_VALIDATE_BOOLEAN, FILTER_NULL_ON_FAILURE);
				return ($bool || $filter !== null || empty($value));
			'decimal' => function($value, $format = null, array $options = array()) {
				if (isset($options['precision'])) {
					$precision = strlen($value) - strrpos($value, '.') - 1;

					if ($precision !== (int) $options['precision']) {
						return false;
				return (filter_var($value, FILTER_VALIDATE_FLOAT, FILTER_NULL_ON_FAILURE) !== null);
			'inList' => function($value, $format, $options) {
				$options += array('list' => array());
				$strict = is_bool($value) || $value === '';
				return in_array($value, $options['list'], $strict);
			'lengthBetween' => function($value, $format, $options) {
				$length = strlen($value);
				$options += array('min' => 1, 'max' => 255);
				return ($length >= $options['min'] && $length <= $options['max']);
			'luhn' => function($value) {
				if (empty($value) || !is_string($value)) {
					return false;
				$sum = 0;
				$length = strlen($value);

				for ($position = 1 - ($length % 2); $position < $length; $position += 2) {
					$sum += $value[$position];
				for ($position = ($length % 2); $position < $length; $position += 2) {
					$number = $value[$position] * 2;
					$sum += ($number < 10) ? $number : $number - 9;
				return ($sum % 10 === 0);
			'numeric' => function($value) {
				return is_numeric($value);
			'inRange' => function($value, $format, $options) {
				$defaults = array('upper' => null, 'lower' => null);
				$options += $defaults;

				if (!is_numeric($value)) {
					return false;
				switch (true) {
					case ($options['upper'] !== null && $options['lower'] !== null):
						return ($value >= $options['lower'] && $value <= $options['upper']);
					case ($options['upper'] !== null):
						return ($value <= $options['upper']);
					case ($options['lower'] !== null):
						return ($value >= $options['lower']);
				return is_finite($value);
			'uuid' => "/^{$alnum}{8}-{$alnum}{4}-{$alnum}{4}-{$alnum}{4}-{$alnum}{12}$/",
			'email' => function($value) {
				return filter_var($value, FILTER_VALIDATE_EMAIL);
			'url' => function($value, $format = null, array $options = array()) {
				$options += array('flags' => array());
				return (boolean) filter_var($value, FILTER_VALIDATE_URL, $options);

		$isEmpty = function($self, $params, $chain) {
			return (empty($value) && $value !== '0') ? false : $chain->next($self, $params, $chain);

		static::$_methodFilters[$class]['alphaNumeric'] = array($isEmpty);
		static::$_methodFilters[$class]['notEmpty'] = array($isEmpty);

		static::$_methodFilters[$class]['creditCard'] = array(function($self, $params, $chain) {
			$options += array('deep' => false);

			if (strlen($value = str_replace(array('-', ' '), '', $value)) < 13) {
				return false;
			if (!$chain->next($self, compact('value') + $params, $chain)) {
				return false;
			return $options['deep'] ? Validator::isLuhn($value) : true;

		static::$_methodFilters[$class]['email'] = array(function($self, $params, $chain) {
			$defaults = array('deep' => false);
			$options += $defaults;

			if (!$chain->next($self, $params, $chain)) {
				return false;
			if (!$options['deep']) {
				return true;
			list($prefix, $host) = explode('@', $params['value']);

			$mxhosts = array();
			if (getmxrr($host, $mxhosts)) {
				return is_array($mxhosts);
			return false;

	 * Maps method calls to validation rule names.  For example, a validation rule that would
	 * normally be called as `Validator::rule('email', '')` can also be called as
	 * `Validator::isEmail('')`.
	 * @param string $method The name of the method called, i.e. `'isEmail'` or `'isCreditCard'`.
	 * @param array $args
	 * @return boolean
	public static function __callStatic($method, $args = array()) {
		if (!isset($args[0])) {
			return false;
		$args = array_filter($args) + array(0 => $args[0], 1 => 'any', 2 => array());
		$rule = preg_replace("/^is([A-Z][A-Za-z0-9]+)$/", '$1', $method);
		$rule[0] = strtolower($rule[0]);
		return static::rule($rule, $args[0], $args[1], $args[2]);

	 * Determines if a given method can be called.
	 * @param string $method Name of the method.
	 * @param boolean $internal Provide `true` to perform check from inside the
	 *                class/object. When `false` checks also for public visibility;
	 *                defaults to `false`.
	 * @return boolean Returns `true` if the method can be called, `false` otherwise.
	public static function respondsTo($method, $internal = false) {
		$rule = preg_replace("/^is([A-Z][A-Za-z0-9]+)$/", '$1', $method);
		$rule[0] = strtolower($rule[0]);
		return isset(static::$_rules[$rule]) || parent::respondsTo($method, $internal);

	 * Checks a set of values against a specified rules list. This method may be used to validate
	 * any arbitrary array of data against a set of validation rules.
	 * @param array $values An array of key/value pairs, where the values are to be checked.
	 * @param array $rules An array of rules to check the values in `$values` against. Each key in
	 *        `$rules` should match a key contained in `$values`, and each value should be a
	 *        validation rule in one of the allowable formats. For example, if you are
	 *        validating a data set containing a `'credit_card'` key, possible values for
	 *        `$rules` would be as follows:
	 *        - `array('credit_card' => 'You must include a credit card number')`: This is the
	 *          simplest form of validation rule, in which the value is simply a message to
	 *          display if the rule fails. Using this format, all other validation settings
	 *          inherit from the defaults, including the validation rule itself, which only
	 *          checks to see that the corresponding key in `$values` is present and contains
	 *          a value that is not empty. _Please note when globalizing validation messages:_
	 *          When specifying messages, it may be preferable to use a code string (i.e.
	 *          `'ERR_NO_TITLE'`) instead of the full text of the validation error. These code
	 *          strings may then be translated by the appropriate tools in the templating layer.
	 *         - `array('credit_card' => array('creditCard', 'message' => 'Invalid CC #'))`:
	 *           In the second format, the validation rule (in this case `creditCard`) and
	 *           associated configuration are specified as an array, where the rule to use is
	 *           the first value in the array (no key), and additional settings are specified
	 *           as other keys in the array. Please see the list below for more information on
	 *           allowed keys.
	 *         - The final format allows you to apply multiple validation rules to a single
	 *           value, and it is specified as follows:
	 *           `array('credit_card' => array(
	 *                array('notEmpty', 'message' => 'You must include credit card number'),
	 *                array('creditCard', 'message' => 'Your credit card number must be valid')
	 *           ));`
	 * @param array $options Validator-specific options.
	 *        Each rule defined as an array can contain any of the following settings
	 *        (in addition to the first value, which represents the rule to be used):
	 *        - `'message'` _string_: The error message to be returned if the validation
	 *          rule fails. See the note above regarding globalization of error messages.
	 *        - `'required`' _boolean_: Represents whether the value is required to be
	 *          present in `$values`. If `'required'` is set to `false`, the validation rule
	 *          will be skipped if the corresponding key is not present. Defaults to `true`.
	 *        - `'skipEmpty'` _boolean_: Similar to `'required'`, this setting (if `true`)
	 *          will cause the validation rule to be skipped if the corresponding value
	 *          is empty (an empty string or `null`). Defaults to `false`.
	 *        - `'format'` _string_: If the validation rule has multiple format definitions
	 *          (see the `add()` or `init()` methods), the name of the format to be used
	 *          can be specified here. Additionally, two special values can be used:
	 *          either `'any'`, which means that all formats will be checked and the rule
	 *          will pass if any format passes, or `'all'`, which requires all formats to
	 *          pass in order for the rule check to succeed.
	 * @return array Returns an array containing all validation failures for data in `$values`,
	 *         where each key matches a key in `$values`, and each value is an array of
	 *         that element's validation errors.
	 * @filter
	public static function check(array $values, array $rules, array $options = array()) {
		$defaults = array(
			'message' => null,
			'required' => true,
			'skipEmpty' => false,
			'format' => 'any',
			'on' => null,
			'last' => false

		$options += $defaults;
		$params = compact('values', 'rules', 'options');

		return static::_filter(__FUNCTION__, $params, function($self, $params) {
			$values = $params['values'];
			$rules = $params['rules'];
			$options = $params['options'];

			$errors = array();
			$events = (array) (isset($options['events']) ? $options['events'] : null);
			$values = Set::flatten($values);

			foreach ($rules as $field => $rules) {
				$rules = is_string($rules) ? array('message' => $rules) : $rules;
				$rules = is_array(current($rules)) ? $rules : array($rules);
				$errors[$field] = array();
				$options['field'] = $field;

				foreach ($rules as $key => $rule) {
					if (array_key_exists('required', $rule) && $rule['required'] === null) {
					$rule += $options + compact('values');
					list($name) = $rule;

					if ($events && $rule['on'] && !array_intersect($events, (array) $rule['on'])) {
					if (!array_key_exists($field, $values)) {
						if ($rule['required']) {
							$errors[$field][] = $rule['message'] ?: $key;
						if ($rule['last']) {
					if (empty($values[$field]) && $rule['skipEmpty']) {

					if (!$self::rule($name, $values[$field], $rule['format'], $rule + $options)) {
						$errors[$field][] = $rule['message'] ?: $key;

						if ($rule['last']) {
			return array_filter($errors);

	 * Adds to or replaces built-in validation rules specified in `Validator::$_rules`.  Any new
	 * validation rules created are automatically callable as validation methods.
	 * For example:
	 * ```
	 * Validator::add('zeroToNine', '/^[0-9]$/');
	 * $isValid = Validator::isZeroToNine("5"); // true
	 * $isValid = Validator::isZeroToNine("20"); // false
	 * ```
	 * Alternatively, the first parameter may be an array of rules expressed as key/value pairs,
	 * as in the following:
	 * ```
	 * Validator::add(array(
	 * 	'zeroToNine' => '/^[0-9]$/',
	 * 	'tenToNineteen' => '/^1[0-9]$/',
	 * ));
	 * ```
	 * In addition to regular expressions, validation rules can also be defined as full anonymous
	 * functions:
	 * ```
	 * use app\models\Account;
	 * Validator::add('accountActive', function($value) {
	 * 	$value = is_int($value) ? Account::find($value) : $value;
	 * 	return (boolean) $value->is_active;
	 * });
	 * $testAccount = Account::create(array('is_active' => false));
	 * Validator::isAccountActive($testAccount); // returns false
	 * ```
	 * These functions can take up to 3 parameters:
	 * 	- `$value` _mixed_: This is the actual value to be validated (as in the above example).
	 * 	- `$format` _string_: Often, validation rules come in multiple "formats", for example:
	 * 	  postal codes, which vary by country or region. Defining multiple formats allows you to
	 * 	  retain flexibility in how you validate data. In cases where a user's country of origin
	 * 	  is known, the appropriate validation rule may be selected. In cases where it is not
	 * 	  known, the value of `$format` may be `'any'`, which should pass if any format matches.
	 * 	  In cases where validation rule formats are not mutually exclusive, the value may be
	 * 	  `'all'`, in which case all must match.
	 * 	- `$options` _array_: This parameter allows a validation rule to implement custom
	 * 	  options.
	 * @see lithium\util\Validator::$_rules
	 * @param mixed $name The name of the validation rule (string), or an array of key/value pairs
	 *        of names and rules.
	 * @param string $rule If $name is a string, this should be a string regular expression, or a
	 *        closure that returns a boolean indicating success. Should be left blank if
	 *        `$name` is an array.
	 * @param array $options The default options for validating this rule. An option which applies
	 *        to all regular expression rules is `'contains'` which, if set to true, allows
	 *        validated values to simply _contain_ a match to a rule, rather than exactly
	 *        matching it in whole.
	public static function add($name, $rule = null, array $options = array()) {
		if (!is_array($name)) {
			$name = array($name => $rule);
		static::$_rules = Set::merge(static::$_rules, $name);

		if (!empty($options)) {
			$options = array_combine(array_keys($name), array_fill(0, count($name), $options));
			static::$_options = Set::merge(static::$_options, $options);

	 * Checks a single value against a single validation rule in one or more formats.
	 * @param string $rule
	 * @param mixed $value
	 * @param string $format
	 * @param array $options
	 * @return boolean Returns `true` or `false` indicating whether the validation rule check
	 *         succeeded or failed.
	 * @filter
	public static function rule($rule, $value, $format = 'any', array $options = array()) {
		if (!isset(static::$_rules[$rule])) {
			throw new InvalidArgumentException("Rule `{$rule}` is not a validation rule.");
		$defaults = isset(static::$_options[$rule]) ? static::$_options[$rule] : array();
		$options = (array) $options + $defaults + static::$_options['defaults'];

		$ruleCheck = static::$_rules[$rule];
		$ruleCheck = is_array($ruleCheck) ? $ruleCheck : array($ruleCheck);

		if (!$options['contains'] && !empty($ruleCheck)) {
			foreach ($ruleCheck as $key => $item) {
				$ruleCheck[$key] = is_string($item) ? "/^{$item}$/" : $item;

		$params = compact('value', 'format', 'options');
		return static::_filter($rule, $params, static::_checkFormats($ruleCheck));

	 * Returns a list of available validation rules, or the configuration details of a single rule.
	 * @param string $name Optional name of a rule to get the details of. If not specified, an array
	 *        of all available rule names is returned. Otherwise, returns the details of a
	 *        single rule. This can be a regular expression string, a closure object, or an
	 *        array of available rule formats made up of string regular expressions,
	 *        closures, or both.
	 * @return mixed Returns either an single array of rule names, or the details of a single rule.
	public static function rules($name = null) {
		if (!$name) {
			return array_keys(static::$_rules);
		return isset(static::$_rules[$name]) ? static::$_rules[$name] : null;

	 * Perform validation checks against a value using an array of all possible formats for a rule,
	 * and an array specifying which formats within the rule to use.
	 * @param array $rules All available rules.
	 * @return \Closure Function returning boolean `true` if validation succeeded, `false` otherwise.
	protected static function _checkFormats($rules) {
		return function($self, $params, $chain) use ($rules) {
			$value = $params['value'];
			$format = $params['format'];
			$options = $params['options'];

			$defaults = array('all' => true);
			$options += $defaults;

			$formats = (array) $format;
			$options['all'] = ($format === 'any');

			foreach ($rules as $index => $check) {
				if (!$options['all'] && !(in_array($index, $formats) || isset($formats[$index]))) {

				$regexPassed = (is_string($check) && preg_match($check, $value));
				$closurePassed = (is_object($check) && $check($value, $format, $options));

				if ($regexPassed || $closurePassed) {
					return true;
			return false;