bootstrapvalidator/src/js/validator/emailAddress.js

(function($) {
    $.fn.bootstrapValidator.i18n.emailAddress = $.extend($.fn.bootstrapValidator.i18n.emailAddress || {}, {
        'default': 'Please enter a valid email address'
    });

    $.fn.bootstrapValidator.validators.emailAddress = {
        html5Attributes: {
            message: 'message',
            multiple: 'multiple',
            separator: 'separator'
        },

        enableByHtml5: function($field) {
            return ('email' === $field.attr('type'));
        },

        /**
         * Return true if and only if the input value is a valid email address
         *
         * @param {BootstrapValidator} validator Validate plugin instance
         * @param {jQuery} $field Field element
         * @param {Object} [options]
         * - multiple: Allow multiple email addresses, separated by a comma or semicolon; default is false.
         * - separator: Regex for character or characters expected as separator between addresses; default is comma /[,;]/, i.e. comma or semicolon.
         * @returns {Boolean}
         */
        validate: function(validator, $field, options) {
            var value = $field.val();
            if (value === '') {
                return true;
            }

            // Email address regular expression
            // http://stackoverflow.com/questions/46155/validate-email-address-in-javascript
            var emailRegExp   = /^(([^<>()[\]\\.,;:\s@\"]+(\.[^<>()[\]\\.,;:\s@\"]+)*)|(\".+\"))@[a-zA-Z0-9](?:[a-zA-Z0-9-]{0,61}[a-zA-Z0-9])?(?:\.[a-zA-Z0-9](?:[a-zA-Z0-9-]{0,61}[a-zA-Z0-9])?)*$/,
                allowMultiple = options.multiple === true || options.multiple === 'true';

            if (allowMultiple) {
                var separator = options.separator || /[,;]/,
                    addresses = this._splitEmailAddresses(value, separator);

                for (var i = 0; i < addresses.length; i++) {
                    if (!emailRegExp.test(addresses[i])) {
                        return false;
                    }
                }

                return true;
            } else {
                return emailRegExp.test(value);
            }
        },

        _splitEmailAddresses: function(emailAddresses, separator) {
            var quotedFragments     = emailAddresses.split(/"/),
                quotedFragmentCount = quotedFragments.length,
                emailAddressArray   = [],
                nextEmailAddress    = '';

            for (var i = 0; i < quotedFragmentCount; i++) {
                if (i % 2 === 0) {
                    var splitEmailAddressFragments     = quotedFragments[i].split(separator),
                        splitEmailAddressFragmentCount = splitEmailAddressFragments.length;

                    if (splitEmailAddressFragmentCount === 1) {
                        nextEmailAddress += splitEmailAddressFragments[0];
                    } else {
                        emailAddressArray.push(nextEmailAddress + splitEmailAddressFragments[0]);

                        for (var j = 1; j < splitEmailAddressFragmentCount - 1; j++) {
                            emailAddressArray.push(splitEmailAddressFragments[j]);
                        }
                        nextEmailAddress = splitEmailAddressFragments[splitEmailAddressFragmentCount - 1];
                    }
                } else {
                    nextEmailAddress += '"' + quotedFragments[i];
                    if (i < quotedFragmentCount - 1) {
                        nextEmailAddress += '"';
                    }
                }
            }

            emailAddressArray.push(nextEmailAddress);
            return emailAddressArray;
        }
    };
}(window.jQuery));