How to customize error message using jQuery.validator placeholders?

Question

I'm trying to add custom form validators. And I'm stuck with message customizing issue.

Let's say I want to check if field value does not exceeds max allowed value. I know that 'Validation Plugin' has a "max" validator already - this is just for sample:

$.validator.addMethod("max-numeric", function(value, element, param) {
    var maxValue = $(element).attr("data-max");
    return (!maxValue) || maxValue >= value;
}, $.validator.format('Applicants must be older than {0} and younger than {1} years of age'));

$("#data-form").validate({
    rules: {
        "form.params1.p4":
        {
            "min-numeric": [5, 6]
        }
    }
});

I cannot comprehend what is responsible for replacing {0} and {1} in '$.validator.format'. And how to pass those parameters?

UPDATE:

Here is the message I get:

Applicants must be older than true and younger than [object HTMLInputElement] years of age

Answer 1

I cannot comprehend what is responsible for replacing {0} and {1} in '$.validator.format' . And how to pass those parameters?

In your example above, {0} represents the first parameter and {1} represents the second parameter. The parameters are [5, 6] respectively and the automatic replacement of such within the message is handled automatically by the plugin.

So when writing a custom method, there is nothing special you'll need to do. If you pass three parameters into your method...

customMethod: [34, 50, 10]

...then you'll have {0} , {1} , and {2} available for your custom message, representing each value of the parameters respectively.

It just works.

---

If there is something going wrong, then it's not obvious from your OP aside from:

The method is called max-numeric , but you're referencing min-numeric in the rules object of the .validate() method.

As long as you have two parameters next to max-numeric , then your example would work.

max-numeric: [5, 6]