carbon-components/src/components/multi-select/README.md

Carbon Components is a component library for IBM Cloud

# `multi-select`

### SCSS

#### Classes

| Name  | Description |
|:------|:-------------|
| `.bx--multi-select` | Used on a container node to specify its control type |

#### Using Form Validation

Carbon Components provides HTML attributes and CSS to enable form validation for each input or control.

For example, here's a __Multiselect__ that provides a message if an option is not selected.

```html
<div role="listbox" tabindex="0" class="bx--multi-select bx--list-box" data-invalid="true">
    <div role="button" class="bx--list-box__field" tabindex="0" type="button" aria-label="open menu" aria-expanded="false" aria-haspopup="true" data-toggle="true">
        <span class="bx--list-box__label">MultiSelect Label</span>
        <div class="bx--list-box__menu-icon">
            <svg fill-rule="evenodd" height="5" role="img" viewBox="0 0 10 5" width="10" alt="Open menu" aria-label="Open menu">
                <title>Open menu</title>
                <path d="M0 0l5 4.998L10 0z"></path>
            </svg>
        </div>
    </div>
</div>
<div class="bx--form-requirement">Please select an option.</div>
```

The `bx--form-requirement` element will be hidden until `data-invalid` attribute gets added to the `bx--multi-select`.
Validate the multiselect on your own and then use JavaScript to add the attribute if the multiselect value is invalid.