Uuid.php

<?php

namespace Drupal\Component\Uuid;


/**
 * UUID Helper methods.
 */
class Uuid {
    
    /**
     * The pattern used to validate a UUID string.
     */
    const VALID_PATTERN = '[0-9a-f]{8}-([0-9a-f]{4}-){3}[0-9a-f]{12}';
    
    /**
     * Checks that a string appears to be in the format of a lower-case UUID.
     *
     * Implementations should not implement validation, since UUIDs should be in
     * a consistent format across all implementations.
     *
     * @param string $uuid
     *   The string to test.
     *
     * @return bool
     *   TRUE if the string is well formed, FALSE otherwise.
     */
    public static function isValid($uuid) {
        return (bool) preg_match('/^' . self::VALID_PATTERN . '$/', $uuid);
    }

}