jquery validate - valid if hidden field has a value

I need to validate a field based on the value of a hidden field. I tried this custom rule:

jQuery.validator.addMethod("cityselected", function() {
    if ($('#featureID').val() == "") return false;
    else return true;
});

cityselect: {
    required: true,
    cityselected: t开发者_如何学编程rue
},

featureID is a hidden input which I need to check has a value. This doesnt seem to work though. Any ideas?

Add the class "required" to the hidden input.

If your plugin version is greater than 1.9, you'll have to explicitly add hidden to the validation process, like that when you initialize the plugin :

$("#form").validate({
  // Do not ignore hidden fields
  ignore: []
});