How to disable custom validation method on condition

Question

I use jQuery Validation plugin to ensure what user entered positive cost_of_car in first text field and positive payment_amount in second text field such what *cost_of_car * 0.4 <= payment_amount <= cost_of_car*:

$.validator.addMethod("testMaxAmount", function()
{
    return $("#cost_of_car").val() - 0 >= $("#payment_amount").val() - 0;
}, "Can't be more than cost_of_car");

$.validator.addMethod("testMinAmount", function()
{
    return $("#cost_of_car").val() * 0.4 <= $("#payment_amount").val() - 0;
}, "Can't be less than cost_of_car * 0.4");

$("#calc_form").validate(
{
    rules: 
    {
        cost_of_car: 
        {
            required: true,
            number: true,
            min: 1,
            max: 10000000
        },
        payment_amount: 
        {
            required: true,
            number: true,
            testMaxAmount: true,
            testMinAmount: true 
        }
    }
});

Now I want to skip testMaxAmount and testMinAmount checks until cost_of_car is valid. Testing

$("#calc_form").validate().element("#cost_of_car")

or even

$("#calc_form").validate({ignore: "#payment_amount"}).element("#cost_of_car")

inside these methods leads to the recursion and hangs browser.

Would you propose some other method to disable validation of payment_amount until cost_of_car is valid, please?

Answer 1

UPDATE: The change has to be in the validator.addMethod() calls:

$.validator.addMethod("testMaxAmount", function()
{
    if($("#cost_of_car").valid())
      return $("#cost_of_car").val() - 0 >= $("#payment_amount").val() - 0;
    else
      return true;
}, "Can't be more than cost_of_car");

$.validator.addMethod("testMinAmount", function()
{
    if($("#cost_of_car").valid())
      return $("#cost_of_car").val() * 0.4 <= $("#payment_amount").val() - 0;
    else
      return true;
}, "Can't be less than cost_of_car * 0.4");