test non-required url

http://stackoverflow.com/questions/12554159/jquery-validation-validate-field-as-url-only-if-it-has-a-value

by ryleyb

HTML

<script src="http://jquery.bassistance.de/validate/jquery.validate.js"></script>
<form id="myform">
<input name="webcast[title]" value="The Title" type="text"><br>
<input name="webcast[survey_url]" value="" type="text"><br>
<input type=submit>
</form>

CSS

label.error{ color: red;  }

JavaScript

$("#myform").validate({
    rules: {
        "webcast[title]": "required",
        "webcast[survey_url]": {
            url: true
        }
    },
    messages: {
        "webcast[title]": {
            required: "Please enter a title for this Webcast."
        },
        "webcast[survey_url]": {
            required: "You must enter a valid URL, or leave blank."
        }
    },
    submitHandler: function(form) {
        alert('successful submit');
    }
});