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    <h3>Editing: class-wc-validation.php</h3>
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/**
 * General user data validation methods
 *
 * @package WooCommerce\Classes
 * @version  2.4.0
 */

defined( 'ABSPATH' ) || exit;

/**
 * Validation class.
 */
class WC_Validation {

	/**
	 * Validates an email using WordPress native is_email function.
	 *
	 * @param  string $email Email address to validate.
	 * @return bool
	 */
	public static function is_email( $email ) {
		return is_email( $email );
	}

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

		return true;
	}

	/**
	 * Checks for a valid postcode.
	 *
	 * @param  string $postcode Postcode to validate.
	 * @param  string $country Country to validate the postcode for.
	 * @return bool
	 */
	public static function is_postcode( $postcode, $country ) {
		if ( strlen( trim( preg_replace( '/[\s\-A-Za-z0-9]/', '', $postcode ) ) ) &gt; 0 ) {
			return false;
		}

		switch ( $country ) {
			case 'AT':
			case 'BE':
			case 'CH':
			case 'HU':
			case 'NO':
				$valid = (bool) preg_match( '/^([0-9]{4})$/', $postcode );
				break;
			case 'BA':
				$valid = (bool) preg_match( '/^([7-8]{1})([0-9]{4})$/', $postcode );
				break;
			case 'BR':
				$valid = (bool) preg_match( '/^([0-9]{5})([-])?([0-9]{3})$/', $postcode );
				break;
			case 'DE':
				$valid = (bool) preg_match( '/^([0]{1}[1-9]{1}|[1-9]{1}[0-9]{1})[0-9]{3}$/', $postcode );
				break;
			case 'DK':
				$valid = (bool) preg_match( '/^(DK-)?([1-24-9]\d{3}|3[0-8]\d{2})$/', $postcode );
				break;
			case 'ES':
			case 'FI':
			case 'EE':
			case 'FR':
			case 'IT':
				$valid = (bool) preg_match( '/^([0-9]{5})$/i', $postcode );
				break;
			case 'GB':
				$valid = self::is_gb_postcode( $postcode );
				break;
			case 'IE':
				$valid = (bool) preg_match( '/([AC-FHKNPRTV-Y]\d{2}|D6W)[0-9AC-FHKNPRTV-Y]{4}/', wc_normalize_postcode( $postcode ) );
				break;
			case 'IN':
				$valid = (bool) preg_match( '/^[1-9]{1}[0-9]{2}\s{0,1}[0-9]{3}$/', $postcode );
				break;
			case 'JP':
				$valid = (bool) preg_match( '/^([0-9]{3})([-]?)([0-9]{4})$/', $postcode );
				break;
			case 'PT':
				$valid = (bool) preg_match( '/^([0-9]{4})([-])([0-9]{3})$/', $postcode );
				break;
			case 'PR':
			case 'US':
				$valid = (bool) preg_match( '/^([0-9]{5})(-[0-9]{4})?$/i', $postcode );
				break;
			case 'CA':
				// CA Postal codes cannot contain D,F,I,O,Q,U and cannot start with W or Z. https://en.wikipedia.org/wiki/Postal_codes_in_Canada#Number_of_possible_postal_codes.
				$valid = (bool) preg_match( '/^([ABCEGHJKLMNPRSTVXY]\d[ABCEGHJKLMNPRSTVWXYZ])([\ ])?(\d[ABCEGHJKLMNPRSTVWXYZ]\d)$/i', $postcode );
				break;
			case 'PL':
				$valid = (bool) preg_match( '/^([0-9]{2})([-])([0-9]{3})$/', $postcode );
				break;
			case 'CZ':
			case 'SE':
			case 'SK':
				$valid = (bool) preg_match( &quot;/^($country-)?([0-9]{3})(\s?)([0-9]{2})$/&quot;, $postcode );
				break;
			case 'NL':
				$valid = (bool) preg_match( '/^([1-9][0-9]{3})(\s?)(?!SA|SD|SS)[A-Z]{2}$/i', $postcode );
				break;
			case 'SI':
				$valid = (bool) preg_match( '/^([1-9][0-9]{3})$/', $postcode );
				break;
			case 'LI':
				$valid = (bool) preg_match( '/^(94[8-9][0-9])$/', $postcode );
				break;
			default:
				$valid = true;
				break;
		}

		return apply_filters( 'woocommerce_validate_postcode', $valid, $postcode, $country );
	}

	/**
	 * Check if is a GB postcode.
	 *
	 * @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.
		// https://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 Postcode to format.
	 * @param  string $country Country to format the postcode for.
	 * @return string  Formatted postcode.
	 */
	public static function format_postcode( $postcode, $country ) {
		return wc_format_postcode( $postcode, $country );
	}

	/**
	 * Format a given phone number.
	 *
	 * @param  mixed $tel Phone number to format.
	 * @return string
	 */
	public static function format_phone( $tel ) {
		return wc_format_phone_number( $tel );
	}
}
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