How to validate jQuery UI combobox values with jQuery Validation Plugin?

Question

I've added jQuery UI combobox with remote source to my form. Now, I am trying to validate that with jQuery Validation Plugin (only values from the list are allowed, field is mandatory).

I've tried standard approach:

 $("#myform").validate({
    focusInvalid: false,
    focusCleanup: true,
    rules: {
      cbCountry: { // combobox
        required: true
      }

But still empty values are allowed. What am I doing wrong?

Update: I've tried to follow @Mike_Laird's advice below and I've found that my custom method

$.validator.addMethod('validComboboxValue', function (value) {
},
...

even not called when applied to jQuery UI combobox. But when I assign the same method to standard text input, it is called.

Answer 1

The basic idea is to set values on each of the select options, and then write a custom validator method to check the option values. Something like the following custom method will make some selection only from the select dropdown required.

jQuery.validator.addMethod(
"selectComboboxCheck",
function (value, element)
    {
    if (element.value === "0") {return false;}
    else return true;
    }
"Required - select an option."
);

Put class="selectComboboxCheck" in the select tag to trigger this method. The select options should look something like

<option value = "1">1</option>