viddl/templates/url-validation.html

<div hx-target="this" hx-swap="outerHTML">
    <label 
        data-tooltip="{{ if .Valid }}Link is Valid{{ else }}Link is invalid{{ end }}" 
        >
        Link
        <input name="URL" id="URL" type="url" hx-post="/valid-link" 
        aria-invalid="{{ if .Valid }}false{{ else }}true{{ end }}" 
        required value="{{ .URL }}"
        hx-indicator="#url-validation-progress"
        >
    </label>
        <progress class="htmx-indicator" id="url-validation-progress"></progress>
</div>