Question

The JQuery validator plugin uses the “name” and I would like to find it dynamically by ID. My $test variable returns a string with the correct name but then I can’t use a string.

How can I use this variable to replace the hard coded name (ctl00$MainContent$ListBox1)?

Instead of:

<script type="text/javascript">
    $(document).ready(function () {
        var $test = $("#ListBox1").attr("name");

        $("#form1").validate({
            rules: {
                ctl00$MainContent$ListBox1: {
                    required: true,
                    rangelength: [0, 4]
                }
            },
            messages: {
                ctl00$MainContent$ListBox1: {
                    required: "Please select a state",
                    rangelength: "Please select maximum 4 states"
                }
            },
            errorLabelContainer: $("#message")
        });
    });
</script>

I would like to use something like:

$("#form1").validate({
     rules: {
         $test: {
              required: true,
              rangelength: [0, 4]
          }
      },

Answer 1

You can’t actually replace a member id. You can however augment objects:

$(document).ready(function () {
    var test = $("#ListBox1").attr("name");
    var validators = {
        rules: {},
        messages: {},
        errorLabelContainer: $("#message")
    };

    validators.rules[test] = {
        required: true,
        rangelength: [0, 4]
    };
    validator.messages[test] = {
        required: "Please select a state",
        rangelength: "Please select maximum 4 states"
    }

    $("#form1").validate(validators);
});

Now your messages and rules object both contain a member with your saved name.