woocommerce/includes/class-wc-validation.php

<?php
/**
 * Contains Validation functions
 *
 * @class 		WC_Validation
 * @version		2.1.0
 * @package		WooCommerce/Classes
 * @category	Class
 * @author 		WooThemes
 */
class WC_Validation {

	/**
	 * Validates an email using wordpress native is_email function
	 *
	 * @param   string	email address
	 * @return  bool
	 */
	public static function is_email( $email ) {
		return is_email( $email );
	}

	/**
	 * Validates a phone number using a regular expression
	 *
	 * @param   string	phone number
	 * @return  bool
	 */
	public static function is_phone( $phone ) {
		if ( strlen( trim( preg_replace( '/[\s\#0-9_\-\+\(\)]/', '', $phone ) ) ) > 0 )
			return false;

		return true;
	}

	/**
	 * Checks for a valid postcode
	 *
	 * @param   string	postcode
	 * @param	string	country
	 * @return  bool
	 */
	public static function is_postcode( $postcode, $country ) {
		if ( strlen( trim( preg_replace( '/[\s\-A-Za-z0-9]/', '', $postcode ) ) ) > 0 )
			return false;

		switch ( $country ) {
			case "GB" :
				return self::is_GB_postcode( $postcode );
			case "US" :
				 if ( preg_match( "/^([0-9]{5})(-[0-9]{4})?$/i", $postcode ) )
				 	return true;
				 else
				 	return false;
			case "CH" :
				 if ( preg_match( "/^([0-9]{4})$/i", $postcode ) )
				 	return true;
				 else
				 	return false;
			case "BR" :
				if ( preg_match( "/^([0-9]{5,5})([-])?([0-9]{3,3})$/", $postcode ) )
					return true;
				else
					return false;
		}

		return true;
	}

	/**
	 * is_GB_postcode function.
	 *
	 * @author John Gardner
	 * @param string $to_check A postcode
	 * @return bool
	 */
	public static function is_GB_postcode( $to_check ) {

		// Permitted letters depend upon their position in the postcode.
		// http://en.wikipedia.org/wiki/Postcodes_in_the_United_Kingdom#Validation
		$alpha1 = "[abcdefghijklmnoprstuwyz]";                          // Character 1
		$alpha2 = "[abcdefghklmnopqrstuvwxy]";                          // Character 2
		$alpha3 = "[abcdefghjkpstuw]";                                  // Character 3 == ABCDEFGHJKPSTUW
		$alpha4 = "[abehmnprvwxy]";                                     // Character 4 == ABEHMNPRVWXY
		$alpha5 = "[abdefghjlnpqrstuwxyz]";                             // Character 5 != CIKMOV

		$pcexp    = array();

		// Expression for postcodes: AN NAA, ANN NAA, AAN NAA, and AANN NAA
		$pcexp[0] = '/^('.$alpha1.'{1}'.$alpha2.'{0,1}[0-9]{1,2})([0-9]{1}'.$alpha5.'{2})$/';

		// Expression for postcodes: ANA NAA
		$pcexp[1] =  '/^('.$alpha1.'{1}[0-9]{1}'.$alpha3.'{1})([0-9]{1}'.$alpha5.'{2})$/';

		// Expression for postcodes: AANA NAA
		$pcexp[2] =  '/^('.$alpha1.'{1}'.$alpha2.'[0-9]{1}'.$alpha4.')([0-9]{1}'.$alpha5.'{2})$/';

		// Exception for the special postcode GIR 0AA
		$pcexp[3] =  '/^(gir)(0aa)$/';

		// Standard BFPO numbers
		$pcexp[4] = '/^(bfpo)([0-9]{1,4})$/';

		// c/o BFPO numbers
		$pcexp[5] = '/^(bfpo)(c\/o[0-9]{1,3})$/';

		// Load up the string to check, converting into lowercase and removing spaces
		$postcode = strtolower( $to_check );
		$postcode = str_replace( ' ', '', $postcode );

		// Assume we are not going to find a valid postcode
		$valid = false;

		// Check the string against the six types of postcodes
		foreach ( $pcexp as $regexp ) {
			if ( preg_match( $regexp, $postcode, $matches ) ) {
				// Remember that we have found that the code is valid and break from loop
				$valid = true;
				break;
			}
		}

		return $valid;
	}

	/**
	 * Format the postcode according to the country and length of the postcode
	 *
	 * @param   string	postcode
	 * @param	string	country
	 * @return  string	formatted postcode
	 */
	public static function format_postcode( $postcode, $country ) {
		wc_format_postcode( $postcode, $country );
	}

	/**
	 * format_phone function.
	 *
	 * @access public
	 * @param mixed $tel
	 * @return string
	 */
	public static function format_phone( $tel ) {
		wc_format_phone_number( $tel );
	}
}