Adding dependent validations using jQuery Validate

While validating one of the many forms, I came accross a situation where a form field’s presence was dependent on another DOM element, depends property of jquery-validate plugin came to resue.

  rules: {
    'contact': {
      required: true,
      email: {
        depends: function(element) {
          return $("#contactform_email").is(":checked");
        }
      },
      number: {
        depends: function(element) {
          return $("#contactform_number").is(":checked");
        }
      }
    }
  }

In the above example, contact is always required, but email and number are dependent on a radio being checked for contact via email and mobile number respectively.

References: .validate() method