navbar-version-selector.html

{{/* set sane defaults */}}
{{ $.Scratch.Set "docLabel" "Version " }}
{{ $.Scratch.Set "activeVersion" .Site.Params.version }}
{{ $curPage := .Page.Section }}
{{/* find version matching the current page */}}
{{ range .Site.Params.versions }}
  {{ if eq $curPage .dirpath }}
	{{ $.Scratch.Add "docLabel" (printf "(%s)" .version) }}
    {{ $.Scratch.Set "activeVersion" .version }}
  {{ end }}
{{ end }}

{{ if .Site.Params.versions }}
<button class="nav-link dropdown-toggle" id="navbarDropdown" role="button" data-toggle="dropdown" data-bs-toggle="dropdown" aria-haspopup="true" aria-expanded="false">
	{{ printf "%s" ($.Scratch.Get "docLabel") }}
</button>
<div class="dropdown-menu" aria-labelledby="navbarDropdownMenuLink">
	{{ range .Site.Params.versions }}
	{{ if and .url (ne .url "") }}
	<a
		class="dropdown-item{{ if eq ( $.Scratch.Get "activeVersion" ) ( printf "%s" .version ) }} active{{ end }}"
		href="{{ cond (gt (len (findRE "^http(s)?://" .url)) 0) .url (relURL .url) }}"
	>
		{{ .version }}
	</a>
	{{ end }}
	{{ end }}
</div>
{{ end }}