Image short tag that supports retina images, page resources, and falls back to plain urls for Hugo websites

image.html

{{- $src := .Get "src" }}
{{- $s := newScratch }}

{{- if eq (len (findRE "^/" $src)) 0 }}
  {{- $s.Set "res" ($.Page.Resources.GetMatch $src) }}
  {{- with ($s.Get "res") }}
    {{- $s.Set "src" .Permalink }}
    {{- if ne (len (findRE "@2x" .Permalink)) 0 }}
      {{- $s.Set "width" (div .Width 2) }}
      {{- $s.Set "height" (div .Height 2) }}
    {{- else }}
      {{- $s.Set "width" .Width }}
      {{- $s.Set "height" .Height }}
    {{- end }}
  {{- else }}
    {{- $s.Set "src" ($src | absURL) }}
  {{- end }}
{{- else }}
  {{- $s.Set "src" ($src | absURL) }}
{{- end -}}

<img src="{{ $s.Get "src" }}"
  {{- with .Get "class" }} class="{{.}}"{{ end }}
  {{- with .Get "alt" }} alt="{{.}}"{{ end }}
  {{- with $s.Get "width" }} width="{{.}}"{{ end }}
  {{- with $s.Get "height" }} height="{{.}}"{{ end }}>