if (typeof $.validator !== 'undefined') {

    $.validator.addMethod("nestedconditionalrequired", function(value, element, params) {
        var dependantProperty = $('input[name="' + params.propertyName + '"]');
        if ((dependantProperty.val() == 'True') && (value == null || value.length <= 0)) {
            return false;
        }
        return true;
    });

    $.validator.unobtrusive.adapters.add('nestedconditionalrequired', ['propertyname'], function(options) {
        options.rules['nestedconditionalrequired'] = { propertyName: options.params.propertyname };
        options.messages['nestedconditionalrequired'] = options.message;
    });

    $.validator.addMethod("nestedmulticonditionalrequired", function(value, element, params) {
        var needsSecondaryProp = true;
        var properties = params.properties.split(',');
        for (var i = 0; i < properties.length; i++) {
            var dependantProperty = $('input[name="' + properties[i] + '"]');
            needsSecondaryProp = needsSecondaryProp && (dependantProperty.val() == 'True');
        }

        if (needsSecondaryProp && (value == null || value.length <= 0)) {
            return false;
        }
        return true;
    });

    $.validator.unobtrusive.adapters.add('nestedmulticonditionalrequired', ['properties'], function(options) {
        options.rules['nestedmulticonditionalrequired'] = { properties: options.params.properties };
        options.messages['nestedmulticonditionalrequired'] = options.message;
    });

    $.validator.addMethod("nullablefileextension", function(value, element, params) {
        if (value == null || value == '') {
            return true;
        }

        var validExtensions = params.validExtensions.split(',');

        var fileExtension = '.' + value.split('.').pop();

        for (var i = 0; i < validExtensions.length; i++) {
            if (fileExtension.toLowerCase() == validExtensions[i].toLowerCase()) {
                return true;
            }
        }

        return false;
    });

    $.validator.unobtrusive.adapters.add('nullablefileextension', ['validextensions'], function(options) {
        options.rules['nullablefileextension'] = { validExtensions: options.params.validextensions };
        options.messages['nullablefileextension'] = options.message;
    });

    $.validator.addMethod("textstringlength", function(value, element, params) {
        if (element === null || typeof element === 'undefined') {
            return true;
        }
        if ($(element).length > 0) {
            var elementValueLength = $('<span></span>').html($(element).val()).text().length;
            return elementValueLength <= params.maxlength;
        }
        return true;
    });

    $.validator.unobtrusive.adapters.add('textstringlength', ['maxlength'], function(options) {
        options.rules['textstringlength'] = { maxlength: options.params.maxlength };
        options.messages['textstringlength'] = options.message;
    });

}