{{- $src := .Get "src" }}
{{- $sub := .Get "sub" -}}
{{- $alt := .Get "alt" -}}
{{ if not .Parent }}
<div class="thumbnail-container">
  {{ end }}
  <a href="{{ $src }}"><div class="thumbnail">
    <center><img src="{{ $src | replaceRE "^(.*static/img)/(.*)$" "$1/w_500/$2" }}" alt="{{ $alt }}" title="{{ $alt }}"></center>
    {{- if $sub -}}
    <center><sub>{{ $sub }}</sub></center>
    {{- end -}}
  </div></a>
  {{ if not .Parent }}
</div>
{{ end }}