hugo-academic/layouts/partials/navbar.html

{{ $current_page := . }}
<nav class="navbar navbar-light fixed-top navbar-expand-lg py-0" id="navbar-main">
  <div class="container">

    <!-- Brand and toggle get grouped for better mobile display -->
      <a class="navbar-brand" href="{{ "/" | relLangURL }}">
        {{- if site.Params.logo -}}
        <img src="{{ printf "/img/%s" site.Params.logo | relURL }}" alt="{{ site.Title }}">
        {{- else -}}
        {{- site.Title -}}
        {{- end -}}
      </a>
      {{ if or site.Menus.main .IsTranslated }}
      <button type="button" class="navbar-toggler" data-toggle="collapse"
              data-target="#navbar" aria-controls="navbar" aria-expanded="false" aria-label="{{ i18n "toggle_navigation" }}">
        <span><i class="fas fa-bars"></i></span>
      </button>
      {{ end }}

    <!-- Collect the nav links, forms, and other content for toggling -->
    <div class="collapse navbar-collapse" id="navbar">

      <!-- Left Nav Bar -->
      {{ $align_right := site.Params.menu_align_right | default true }}
      <ul class="navbar-nav {{ if $align_right }}ml-auto{{ else }}mr-auto{{ end }}">
        {{ range site.Menus.main }}

        {{ if .HasChildren }}
        <li class="nav-item dropdown">
          <a href="#" class="nav-link dropdown-toggle" data-toggle="dropdown" aria-haspopup="true">
            {{- .Pre -}}<span>{{ .Name | safeHTML }}</span>{{- .Post -}}
            <span class="caret"></span>
          </a>
          <ul class="dropdown-menu">
            {{ range .Children }}
            <li class="dropdown-item my-0 py-0 mx-0 px-0">
              <a href="{{ .URL | relLangURL }}"{{ if $.IsHome }} data-target="{{ .URL }}"{{ end }}>
                {{- .Pre -}}<span>{{ .Name | safeHTML }}</span>{{- .Post -}}
              </a>
            </li>
            {{ end }}
          </ul>
        </li>

        {{ else }}

        {{/* Set target for link. */}}
        {{ $.Scratch.Set "target" "" }}
        {{ if gt (len .URL) 4 }}
          {{ if eq "http" (slicestr .URL 0 4) }}
            {{ $.Scratch.Set "target" " target=\"_blank\" rel=\"noopener\"" }}
          {{ end }}
        {{ end }}

        {{/* Get active page. */}}
        {{ $is_link_in_current_path := in $current_page.RelPermalink .URL }}
        {{ $is_widget_page := or $current_page.IsHome (eq $current_page.Type "widget_page") }}
        {{ $hash := findRE "#(.+)" .URL }}
        {{ $is_same_page := $is_link_in_current_path }}
        {{ if gt (len $hash) 0 }}
          {{ $hash = index $hash 0 }}
          {{ $hash_removed := replace .URL $hash "" }}
          {{ if eq (len $hash_removed) 0 }}
            {{ $hash_removed = "/" }}{{/* Add robustness for `/#SECTION` or `#SECTION` in `menus.toml`. */}}
          {{ end }}
          {{ $is_same_page = eq (path.Dir $current_page.RelPermalink) (path.Dir ($hash_removed|relLangURL)) }}
        {{ end }}

        <li class="nav-item">
          <a class="nav-link {{if $is_link_in_current_path }} active{{end}}" href="{{.URL | relLangURL}}"{{ if and $is_widget_page $is_same_page }} data-target="{{$hash}}"{{ end }}{{ ($.Scratch.Get "target") | safeHTMLAttr }}>
            {{- .Pre -}}<span>{{ .Name | safeHTML }}</span>{{- .Post -}}
          </a>
        </li>

        {{ end }}
        {{ end }}

      {{ if not $align_right | and (.IsTranslated | or site.Menus.main_right | or site.Params.search.engine | or site.Params.day_night) }}
      </ul>
      <ul class="navbar-nav ml-auto">
      {{ end }}

        {{ range site.Menus.main_right }}

        {{/* Set target for link. */}}
        {{ $.Scratch.Set "target" "" }}
        {{ if gt (len .URL) 4 }}
        {{ if eq "http" (slicestr .URL 0 4) }}
        {{ $.Scratch.Set "target" " target=\"_blank\" rel=\"noopener\"" }}
        {{ end }}
        {{ end }}

        <li class="nav-item">
          <a class="nav-link" href="{{ .URL | relLangURL }}"{{ if $.IsHome }} data-target="{{ .URL }}"{{ end }}{{ ($.Scratch.Get "target") | safeHTMLAttr }}>
            {{- .Pre -}}<span>{{ .Name | safeHTML }}</span>{{- .Post -}}
          </a>
        </li>

        {{ end }}

        {{ if site.Params.search.engine }}
        <li class="nav-item">
          <a class="nav-link js-search" href="#"><i class="fas fa-search" aria-hidden="true"></i></a>
        </li>
        {{ end }}

        {{ if .IsTranslated }}
        <li class="nav-item dropdown">
          <a href="#" class="nav-link dropdown-toggle" data-toggle="dropdown" aria-haspopup="true">
            <i class="fas fa-globe" aria-hidden="true"></i>
            <span>{{ index site.Data.i18n.languages .Lang }}</span>
          </a>
          <ul class="dropdown-menu">
            {{ range .Translations }}
            <li class="dropdown-item my-0 py-0 mx-0 px-0">
              <a href="{{ .Permalink }}"{{ if $.IsHome }} data-target="{{ .URL }}"{{ end }}>
                <span>{{ index site.Data.i18n.languages .Lang }}</span>
              </a>
            </li>
            {{ end }}
          </ul>
        </li>
        {{ end }}

        {{ if site.Params.day_night }}
        <li class="nav-item">
          <a class="nav-link js-dark-toggle" href="#"><i class="fas fa-moon" aria-hidden="true"></i></a>
        </li>
        {{ end }}

      </ul>

    </div><!-- /.navbar-collapse -->
  </div><!-- /.container -->
</nav>