FormValidation v0.8.1 is released, supports Bootstrap 4 alpha 3

Playing with Bootstrap Multiselect

Use with the Bootstrap Multiselect plugin.

You should look at the basic principles when integrating FormValidation with other plugins

In order to display the feedback icon at the right place when using with the enableFiltering option, the multiple select element must be initialized after calling .formValidation() on form:

$('#multiselectForm')
    // Initializing formValidation first
    .formValidation({
        excluded: ':disabled',
        ...
    })
    .find('[name="gender"]')
        .multiselect({
            ...
        })
        .end()
    .find('[name="browsers"]')
        // And multiselect later
        .multiselect({
            enableFiltering: true,
            includeSelectAllOption: true,
            ...
        })
        .end();

In the following example, the Browser option requires to choose 2-3 browsers.

<!-- Include Bootstrap Multiselect CSS, JS -->
<link rel="stylesheet" href="/vendor/bootstrap-multiselect/css/bootstrap-multiselect.css" />
<script src="/vendor/bootstrap-multiselect/js/bootstrap-multiselect.js"></script>

<form id="multiselectForm" method="post" class="form-horizontal">
    <div class="form-group">
        <label class="col-xs-3 control-label">Gender</label>
        <div class="col-xs-5">
            <select class="form-control" name="gender">
                <option value="male">Male</option>
                <option value="female">Female</option>
                <option value="other">Other</option>
            </select>
        </div>
    </div>

    <div class="form-group">
        <label class="col-xs-3 control-label">Browser</label>
        <div class="col-xs-5">
            <select class="form-control" name="browsers" multiple>
                <option value="chrome">Google Chrome</option>
                <option value="firefox">Firefox</option>
                <option value="ie">IE</option>
                <option value="safari">Safari</option>
                <option value="opera">Opera</option>
                <option value="other">Other</option>
            </select>
        </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() {
    // You don't need to care about onDropdownShow, onDropdownHide options
    // and adjustByScrollHeight(), adjustByHeight() methods
    // They are for this specific demo
    $('#multiselectForm')
        .formValidation({
            framework: 'bootstrap',
            // Exclude only disabled fields
            // The invisible fields set by Bootstrap Multiselect must be validated
            excluded: ':disabled',
            icon: {
                valid: 'glyphicon glyphicon-ok',
                invalid: 'glyphicon glyphicon-remove',
                validating: 'glyphicon glyphicon-refresh'
            },
            fields: {
                gender: {
                    validators: {
                        notEmpty: {
                            message: 'The gender is required'
                        }
                    }
                },
                browsers: {
                    validators: {
                        callback: {
                            message: 'Please choose 2-3 browsers you use for developing',
                            callback: function(value, validator, $field) {
                                // Get the selected options
                                var options = validator.getFieldElements('browsers').val();
                                return (options != null
                                        && options.length >= 2 && options.length <= 3);
                            }
                        }
                    }
                }
            }
        })
        .find('[name="gender"]')
            .multiselect({
                onChange: function(element, checked) {
                    $('#multiselectForm').formValidation('revalidateField', 'gender');

                    adjustByScrollHeight();
                },
                onDropdownShown: function(e) {
                    adjustByScrollHeight();
                },
                onDropdownHidden: function(e) {
                    adjustByHeight();
                }
            })
            .end()
        .find('[name="browsers"]')
            .multiselect({
                enableFiltering: true,
                includeSelectAllOption: true,
                // Re-validate the multiselect field when it is changed
                onChange: function(element, checked) {
                    $('#multiselectForm').formValidation('revalidateField', 'browsers');

                    adjustByScrollHeight();
                },
                onDropdownShown: function(e) {
                    adjustByScrollHeight();
                },
                onDropdownHidden: function(e) {
                    adjustByHeight();
                }
            })
            .end();

    // You don't need to care about these methods
    function adjustByHeight() {
        var $body   = $('body'),
            $iframe = $body.data('iframe.fv');
        if ($iframe) {
            // Adjust the height of iframe when hiding the picker
            $iframe.height($body.height());
        }
    }

    function adjustByScrollHeight() {
        var $body   = $('body'),
            $iframe = $body.data('iframe.fv');
        if ($iframe) {
            // Adjust the height of iframe when showing the picker
            $iframe.height($body.get(0).scrollHeight);
        }
    }
});
</script>