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Using jQuery validation plugin, need to ensure at least one checkbox is checked when names are different

Hi Experts,

On a web form, I have a set of checkboxes that form a logical group but do not have the same name. Using the jQuery validation plugin (http://docs.jquery.com/Plugins/Validation), I need to add a custom validation method and rule to ensure that the user checks at least one checkbox.

I've read the documentation on jquery.com and understand the basics of adding a method and rule, but I haven't been able to work out the specifics for this particular scenario.

Fair warning :) I already found http://osdir.com/answers/javascript/16692-jquery-validation-plugin-validate-checkboxes-dont-have-samename.html and this does *not* provide the detail I'm looking for. Points won't be given for a reference to this page or anything similar, or for an answer that says, "Write a custom rule." I already figured that part out :) I set the points higher because I'm looking for actual code for the custom method and rule.

Thanks in advance--

Kathryn

<input type="checkbox" name="length" value="length">
<input type="checkbox" name="density" value="density">
<input type="checkbox" name="packaging" value="packaging">
<input type="checkbox" name="loose" value="loose">

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anoyes

I think this should work for you. You might also want to look into doing custom error positioning, so that only one error shows up, perhaps at the start of the checkbox list, which is also included in the script below.

<script type="text/javascript">
$.validator.methods.checkboxGroup = function(value,element,param)
{
  return (
    $("input[name='length']").is(':checked') ||
    $("input[name='density']").is(':checked') ||
    $("input[name='packaging']").is(':checked') ||
    $("input[name='loose']").is(':checked')
  );
}
 
$('form').validate({
  rules: {
    length: "checkboxGroup",
    density: "checkboxGroup",
    packaging: "checkboxGroup",
    loose: "checkboxGroup",
    //etc
  },
  errorPlacement: function(err, el) {
    var name = $(el).attr('name');
    if (name == 'length' || name=='density' || name=='packaging' || name=='loose')
    {
      err.insertBefore(el);
    }
    else
    {
      err.insertAfter(el);
    }
  }
});
</script>

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KathrynGZ

ASKER

anoyes,

YOU ROCK! That's exactly what I was looking for. Thank you!

Just one more detail: it's telling me no error message was defined. Do you know how to add that? (I know how to add a message with validator.addMethod, but the same thing didn't work with validator.methods).

Thank you!

Kathryn

ASKER CERTIFIED SOLUTION

anoyes

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KathrynGZ

ASKER

If I could have given you an A+, I would have :) Thanks again!