bootstrapvalidator/src/js/validator/isbn.js

(function($) {
    $.fn.bootstrapValidator.validators.isbn = {
        /**
         * Return true if the input value is a valid ISBN 10 or ISBN 13 number
         * Examples:
         * - Valid:
         * ISBN 10: 99921-58-10-7, 9971-5-0210-0, 960-425-059-0, 80-902734-1-6, 85-359-0277-5, 1-84356-028-3, 0-684-84328-5, 0-8044-2957-X, 0-85131-041-9, 0-943396-04-2, 0-9752298-0-X
         * ISBN 13: 978-0-306-40615-7
         * - Invalid:
         * ISBN 10: 99921-58-10-6
         * ISBN 13: 978-0-306-40615-6
         *
         * @see http://en.wikipedia.org/wiki/International_Standard_Book_Number
         * @param {BootstrapValidator} validator The validator plugin instance
         * @param {jQuery} $field Field element
         * @param {Object} options Can consist of the following keys:
         * - message: The invalid message
         * @returns {Boolean}
         */
        validate: function(validator, $field, options) {
            var value = $field.val();
            if (value == '') {
                return true;
            }

            // http://en.wikipedia.org/wiki/International_Standard_Book_Number#Overview
            // Groups are separated by a hyphen or a space
            var type;
            switch (true) {
                case /^\d{9}[\dX]$/.test(value):
                case (value.length == 13 && /^(\d+)-(\d+)-(\d+)-([\dX])$/.test(value)):
                case (value.length == 13 && /^(\d+)\s(\d+)\s(\d+)\s([\dX])$/.test(value)):
                    type = 'ISBN10';
                    break;
                case /^(978|979)\d{9}[\dX]$/.test(value):
                case (value.length == 17 && /^(978|979)-(\d+)-(\d+)-(\d+)-([\dX])$/.test(value)):
                case (value.length == 17 && /^(978|979)\s(\d+)\s(\d+)\s(\d+)\s([\dX])$/.test(value)):
                    type = 'ISBN13';
                    break;
                default:
                    return false;
            }

            // Replace all special characters except digits and X
            value = value.replace(/[^0-9X]/gi, '');
            var chars  = value.split(''),
                length = chars.length,
                sum    = 0,
                checksum;

            switch (type) {
                case 'ISBN10':
                    sum = 0;
                    for (var i = 0; i < length - 1; i++) {
                        sum += ((10 - i) * parseInt(chars[i]));
                    }
                    checksum = 11 - (sum % 11);
                    if (checksum == 11) {
                        checksum = 0;
                    } else if (checksum == 10) {
                        checksum = 'X';
                    }
                    return (checksum + '' == chars[length - 1]);

                case 'ISBN13':
                    sum = 0;
                    for (var i = 0; i < length - 1; i++) {
                        sum += ((i % 2 == 0) ? parseInt(chars[i]) : (parseInt(chars[i]) * 3));
                    }
                    checksum = 10 - (sum % 10);
                    if (checksum == 10) {
                        checksum = '0';
                    }
                    return (checksum + '' == chars[length - 1]);

                default:
                    return false;
            }
        }
    };
}(window.jQuery));