Foundation 5 & Abide: a custom validator for a set of checkboxes?

Question

I would like to create a validator for abide for a set of checkboxes.

Let's consider a set of 5 checkboxes. The user is asked to check 3 max, and at least 1.

So, here is my work-in-progress code:

<div data-abide-validator='checkboxes' data-abide-validator-values='1,3'>
    <input type="checkbox"/>
    <input type="checkbox"/>
    <input type="checkbox"/>
    <input type="checkbox"/>
    <input type="checkbox"/>
</div>

<script>
    $(document).foundation({
        validators: {
            checkboxes: function(el, required, parent) {
                var countC = el.find(':checked').length;
                alert(countC);
            }
        }
    });
</script>

At this point, I just try to count the checked inputs. But it seems I can't even trigger the validator... I think I could manage to code my validation stuff if only I could figure out how to trigger it.

Indeed I didn't find many examples of the custom validator, and the official doc did not help me much.

Answer 1

Your HTML markup is not really "correct" for abide. You should be attaching the data-abide-validator attribute to the inputs, not the parent div. Additionally, you need some better markup so abide's default error display can work (and some better use of foundation's grid system to lay it out). I would point you toward the Abide Validation Page on Zurb's site for some examples of form markup.

I've taken the liberty of restructuring your markup to be something that is more becoming of a foundation layout:

<form action="/echo/html/" method="POST" data-abide>
    <div class="row">
        <div class="small-12 columns checkbox-group" data-abide-validator-limit="1,3">
            <label>Check some boxes</label>
            <small class="error">You have checked an invalid number of boxes.</small>
            <ul class="small-block-grid-3">
                <li>
                    <label>
                        <input type="checkbox" data-abide-validator="checkbox_limit" value="1" /> 1
                    </label>
                </li>
                <li>
                    <label>
                        <input type="checkbox" data-abide-validator="checkbox_limit" value="2" /> 2
                    </label>
                </li>
                <li>
                    <label>
                        <input type="checkbox" data-abide-validator="checkbox_limit" value="3" /> 3
                    </label>
                </li>
                <li>
                    <label>
                        <input type="checkbox" data-abide-validator="checkbox_limit" value="4" /> 4
                    </label>
                </li>
                <li>
                    <label>
                        <input type="checkbox" data-abide-validator="checkbox_limit" value="5" /> 5
                    </label>
                </li>
            </ul>
        </div>
    </div>
    <div class="row">
        <div class="small-12 columns">
            <button type="submit">Submit</button>
        </div>
    </div>
</form>

As to your JS code. It's not correct either. You need to address the abide -> validators namespace of the options, not just validators. I've rewritten your JS code to not only do that, but give the desired effect you wanted:

$(document).foundation({
    abide: {
        validators: {
            checkbox_limit: function(el, required, parent) {
                var group = parent.closest( '.checkbox-group' );
                var limit = group.attr('data-abide-validator-limit').split(',');
                var countC = group.find(':checked').length;
                if( countC >= limit[0] && countC <= limit[1] ) {
                    group.find('small.error').hide();
                    //return true so abide can clear any invalid flags on this element
                    return true;
                } else {
                    group.find('small.error').css({display:'block'});
                    //return false and let abide do its thing to make sure the form doesn't submit
                    return false;
                }
            }
        }
    }
});

In order to check adjacent elements when doing custom validation, you need to have something to target. The el variable in the validation function will be the DOM element of the input/field that is being validated. The required variable will tell you if the field is flagged as being required or not (boolean). The parent variable will be set to the "parent" of the field. I say "parent" because although the label tag is technically the parent of the input element, abide is smart enough to realize that the label is part of the field's element structure and skip over it to the li element instead.

From there, you need a way to identify a common parent. So I added the checkbox-group class to whatever element I decided to make the "parent" of all the checkboxes in the group. This is not a Foundation or Abide "magic" class, but rather something of my own creation for use in the validation function.

From there, you can easily trace the few lines of the validation function to see the workflow: Find the group container object, parse the limits off the container's data-abide-validator-limits attribute, count the number of checked inputs in the container, check if the number checked is between the limits, display/hide the error message and return true/false so abide knows if the field validated or not.

I've got a working Fiddle of it if you care to check it out yourself ;) Hopefully this was informative for you, and I wish you the best of luck playing with the awesome that is Foundation!