jQuery validate: How to add a rule for regular expression validation?

I am using the jQuery validation plugin. Great stuff! I want to migrate my existing ASP.NET solution to use jQuery instead of the ASP.NET validators. I am missing a replacement for the regular expression validator. I want to be able to do something like this:

$("Textbox").rules("add", { regularExpression: "^[a-zA-Z'.\s]{1,40}$" })

How do I add a custom rule to achieve this?


Thanks to the answer of redsquare I added a method like this:

$.validator.addMethod(
  "regex",
  function(value, element, regexp) {
    var re = new RegExp(regexp);
    return this.optional(element) || re.test(value);
  },
  "Please check your input."
);

Now all you need to do to validate against any regex is this:

$("#Textbox").rules("add", { regex: "^[a-zA-Z'.\\s]{1,40}$" })

Additionally, it looks like there is a file called additional-methods.js that contains the method "pattern", which can be a RegExp when created using the method without quotes.


Edit

The pattern function is now the preferred way to do this, making the example:

$("#Textbox").rules("add", { pattern: "^[a-zA-Z'.\\s]{1,40}$" })
  • https://cdnjs.com/libraries/jquery-validate
    • https://cdnjs.cloudflare.com/ajax/libs/jquery-validate/1.19.2/jquery.validate.min.js
    • https://cdnjs.cloudflare.com/ajax/libs/jquery-validate/1.19.2/additional-methods.min.js

You can use the addMethod()

e.g

$.validator.addMethod('postalCode', function (value) { 
    return /^((\d{5}-\d{4})|(\d{5})|([A-Z]\d[A-Z]\s\d[A-Z]\d))$/.test(value); 
}, 'Please enter a valid US or Canadian postal code.');

good article here https://web.archive.org/web/20130609222116/http://www.randallmorey.com/blog/2008/mar/16/extending-jquery-form-validation-plugin/


I had some trouble putting together all the pieces for doing a jQuery regular expression validator, but I got it to work... Here is a complete working example. It uses the 'Validation' plugin which can be found in jQuery Validation Plugin

<!DOCTYPE html PUBLIC "-//W3C//DTD XHTML 1.0 Strict//EN" "http://www.w3.org/TR/xhtml1/DTD/xhtml1-strict.dtd">
<html xmlns="http://www.w3.org/1999/xhtml">
<head>
    <meta http-equiv="Content-Type" content="text/html; charset=UTF-8" />
    <script src="http://YOURJQUERYPATH/js/jquery.js" type="text/javascript"></script>
    <script src="http://YOURJQUERYPATH/js/jquery.validate.js" type="text/javascript"></script>
    <script type="text/javascript">

        $().ready(function() {
            $.validator.addMethod("EMAIL", function(value, element) {
                return this.optional(element) || /^[a-zA-Z0-9._-]+@[a-zA-Z0-9-]+\.[a-zA-Z.]{2,5}$/i.test(value);
            }, "Email Address is invalid: Please enter a valid email address.");

            $.validator.addMethod("PASSWORD",function(value,element){
                return this.optional(element) || /^(?=.*\d)(?=.*[a-z])(?=.*[A-Z]).{8,16}$/i.test(value);
            },"Passwords are 8-16 characters with uppercase letters, lowercase letters and at least one number.");

            $.validator.addMethod("SUBMIT",function(value,element){
                return this.optional(element) || /[^ ]/i.test(value);
            },"You did not click the submit button.");

            // Validate signup form on keyup and submit
            $("#LOGIN").validate({
                rules: {
                    EMAIL: "required EMAIL",
                    PASSWORD: "required PASSWORD",
                    SUBMIT: "required SUBMIT",
                },
            });
        });
    </script>
</head>
<body>
    <div id="LOGIN_FORM" class="form">
        <form id="LOGIN" name="LOGIN" method="post" action="/index/secure/authentication?action=login">
            <h1>Log In</h1>
            <div id="LOGIN_EMAIL">
                <label for="EMAIL">Email Address</label>
                <input id="EMAIL" name="EMAIL" type="text" value="" tabindex="1" />
            </div>
            <div id="LOGIN_PASSWORD">
                <label for="PASSWORD">Password</label>
                <input id="PASSWORD" name="PASSWORD" type="password" value="" tabindex="2" />
            </div>
            <div id="LOGIN_SUBMIT">
                <input id="SUBMIT" name="SUBMIT" type="submit" value="Submit" tabindex="3" />
            </div>
        </form>
    </div>
</body>
</html>

No reason to define the regex as a string.

$.validator.addMethod(
    "regex",
    function(value, element, regexp) {
        var check = false;
        return this.optional(element) || regexp.test(value);
    },
    "Please check your input."
);

and

telephone: { required: true, regex : /^[\d\s]+$/, minlength: 5 },

tis better this way, no?


Extending PeterTheNiceGuy's answer a bit:

$.validator.addMethod(
        "regex",
        function(value, element, regexp) {
            if (regexp.constructor != RegExp)
                regexp = new RegExp(regexp);
            else if (regexp.global)
                regexp.lastIndex = 0;
            return this.optional(element) || regexp.test(value);
        },
        "Please check your input."
);

This would allow you to pass a regex object to the rule.

$("Textbox").rules("add", { regex: /^[a-zA-Z'.\s]{1,40}$/ });

Resetting the lastIndex property is necessary when the g-flag is set on the RegExp object. Otherwise it would start validating from the position of the last match with that regex, even if the subject string is different.

Some other ideas I had was be to enable you use arrays of regex's, and another rule for the negation of regex's:

$("password").rules("add", {
    regex: [
        /^[a-zA-Z'.\s]{8,40}$/,
        /^.*[a-z].*$/,
        /^.*[A-Z].*$/,
        /^.*[0-9].*$/
    ],
    '!regex': /password|123/
});

But implementing those would maybe be too much.