Playing with Bootstrap Tags Input

Use with the Bootstrap Tags Input plugin.
You should look at the basic principles when integrating FormValidation with other plugins
The Cities field requires to enter at least one city you like most.
The Countries field requires to enter 2-4 countries you like most.
<link rel="stylesheet" href="//cdn.jsdelivr.net/bootstrap.tagsinput/0.4.2/bootstrap-tagsinput.css" />
<script src="//cdn.jsdelivr.net/bootstrap.tagsinput/0.4.2/bootstrap-tagsinput.min.js"></script>

<style type="text/css">
.bootstrap-tagsinput {
    width: 100%;
}
.label {
    line-height: 2 !important;
}
</style>

<form id="bootstrapTagsInputForm" method="post" class="form-horizontal">
    <div class="form-group">
        <label class="col-xs-3 control-label">Cities</label>
        <div class="col-xs-8">
            <input type="text" name="cities" class="form-control"
                   value="Hanoi" data-role="tagsinput" />
        </div>
    </div>
    <div class="form-group">
        <label class="col-xs-3 control-label">Countries</label>
        <div class="col-xs-8">
            <input type="text" name="countries" class="form-control"
                   value="Vietnam" data-role="tagsinput" />
        </div>
    </div>
    <div class="form-group">
        <div class="col-xs-5 col-xs-offset-3">
            <button type="submit" class="btn btn-default">Validate</button>
        </div>
    </div>
</form>

<script>
$(document).ready(function () {
    $('#bootstrapTagsInputForm')
        .find('[name="cities"]')
            // Revalidate the cities field when it is changed
            .change(function (e) {
                $('#bootstrapTagsInputForm').formValidation('revalidateField', 'cities');
            })
            .end()
        .find('[name="countries"]')
            // Revalidate the countries field when it is changed
            .change(function (e) {
                $('#bootstrapTagsInputForm').formValidation('revalidateField', 'countries');
            })
            .end()
        .formValidation({
            framework: 'bootstrap',
            excluded: ':disabled',
            icon: {
                valid: 'glyphicon glyphicon-ok',
                invalid: 'glyphicon glyphicon-remove',
                validating: 'glyphicon glyphicon-refresh'
            },
            fields: {
                cities: {
                    validators: {
                        notEmpty: {
                            message: 'Please enter at least one city you like the most.'
                        }
                    }
                },
                countries: {
                    validators: {
                        callback: {
                            message: 'Please enter 2-4 countries you like most.',
                            callback: function (value, validator, $field) {
                                // Get the entered elements
                                var options = validator.getFieldElements('countries').tagsinput('items');
                                return (options !== null && options.length >= 2 && options.length <= 4);
                            }
                        }
                    }
                }
            }
        });
});
</script>