www.byjp.me/layouts/shortcodes/openlibrary.html

{{- $path := .Page.Path -}}
{{- $isbn := "" -}}
{{- $key := "" -}}
{{- $showCover := ne (.Get 1) false -}}

{{- with .Get 0 -}}
  {{- if eq (len .) 13 -}}
    {{- $isbn = . -}}
  {{- else -}}
    {{- $key = . -}}
  {{- end -}}
{{- end -}}

{{- if not $key -}}
  {{- $query := (dict "type" "/type/edition" "isbn_13" $isbn) | jsonify -}}
  {{- with resources.GetRemote (printf "https://openlibrary.org/api/things?query=%s" ($query)) -}}
    {{- with .Err -}}
      {{- errorf "Error grabbing Thing from OpenLibrary: %v" . -}}
    {{- else -}}
      {{- $thing := .Content | transform.Unmarshal -}}
      {{- if and (eq $thing.status "ok") (ge (len $thing.result) 1) -}}
        {{- $key = index $thing.result 0 -}}
      {{- end -}}
    {{- end -}}
  {{- else -}}
    {{- warnf "Failed to fetch ISBN data from OpenLibrary: %s" $isbn -}}
  {{- end -}}
{{- end -}}

{{- if $key -}}
  {{- with resources.GetRemote (printf "https://openlibrary.org/api/get?key=%s" $key) -}}
    {{- with .Err -}}
      {{- errorf "Error grabbing Book data from OpenLibrary: %v" . -}}
    {{- else -}}
      {{- $bookObj := .Content | transform.Unmarshal -}}
      {{- if eq $bookObj.status "ok" -}}
        {{- $isbn = index $bookObj.result.isbn_13 0 -}}

        {{- $authors := slice -}}
        {{- range $bookObj.result.authors -}}
          {{- with resources.GetRemote (printf "https://openlibrary.org/api/get?key=%s" .key) -}}
            {{- with .Err -}}
              {{- errorf "Error grabbing Author data from OpenLibrary: %v" . -}}
            {{- else -}}
              {{- $authorObj := .Content | transform.Unmarshal -}}
              {{- if eq $authorObj.status "ok" -}}
                {{- $authors = $authors | append (dict "name" $authorObj.result.name "url" (printf "https://openlibrary.org%s" $authorObj.result.key)) -}}
              {{- end -}}
            {{- end -}}
          {{- else -}}
            {{- warnf "Failed to fetch Author data from OpenLibrary: %s" .key -}}
          {{- end -}}
        {{- end -}}

        {{- $cover := "" -}}
        {{- if $showCover -}}
          {{- $coverURL := (printf "https://covers.openlibrary.org/b/isbn/%s-M.jpg" $isbn) -}}
          {{- if not $isbn -}}
            {{- $coverURL = printf "https://covers.openlibrary.org/b/id/%.0f-M.jpg" (index $bookObj.result.covers 0) -}}
          {{- end -}}

          {{- $bookFilename := replaceRE `[^a-z]+` "-" (lower $bookObj.result.title) -}}
          {{- $coverPath := replaceRE `(\.md)?$` (printf "/%s.jpg" $bookFilename) $path -}}
          {{- with resources.GetRemote $coverURL -}}
            {{- with .Err -}}
            {{- else -}}
              {{- $cover = .Content | resources.FromString $coverPath -}}
            {{- end -}}
          {{- end -}}
        {{- end -}}

        {{- $book := dict "title" $bookObj.result.title "authors" $authors "url" (printf "https://openlibrary.org%s" $key) "cover" $cover -}}
        {{- partial "book.html" $book -}}
      {{- end -}}
    {{- end -}}
  {{- else -}}
    {{- warnf "Failed to fetch Book data data from OpenLibrary: %s" $key -}}
  {{- end -}}
{{- end -}}