<!-- DefinedTermSet Schema.org Type -->
<!-- https://schema.org/DefinedTermSet -->

<!-- For a glossary: the page is the set and each entry is a DefinedTerm.

     Like the Product and FAQPage partials, this emits structured data and
     nothing visible. The glossary itself is written in the page body, and the
     anchors here have to match the headings there.

     A term may nest others under `items:`; they are flattened into the one set,
     in reading order, because DefinedTerm has no hierarchy of its own and a
     glossary is a set.

     `description` is markdown, so here it is rendered, stripped of its tags and
     unescaped back to the words a reader sees. It is not cut short: schema.org
     sets no length on the property, and reducing it to the first sentence
     mangled every description whose first period was not followed by a space,
     which is every description that ends there.

     `alternateName`, `sameAs` and `termCode` are optional and carry the names
     schema.org gives them. Each is passed through as written, a string or a
     list, the way head/schema-organization.html passes its own sameAs. sameAs
     is the one that earns its place: it ties the entry to the entity it names,
     on Wikidata or wherever, so the term stops being a string that exists only
     on this page.

     `anchor` is optional. Left out, it is derived from the term with
     `anchorize`, the rule Hugo applies to markdown headings, so a term whose
     heading reads the same as the term needs nothing. Give it explicitly when
     the heading and the term differ, or when an anchor has to stay stable for
     old links. It is deliberately not called `id`: schema.org has no such
     property, and the name would sit next to the JSON-LD `@id`, `identifier`
     and `termCode`, none of which it is.

     The set is identified by `#glossary` rather than by the page URL. The page
     URL is already the Article's mainEntityOfPage, and claiming it as the @id
     here would type that same node as a glossary.

     Built as a map and emitted in one interpolation: Hugo serialises it as
     JSON, so optional fields can never leave a dangling comma behind. -->

{{ with .Params.definedTermSet }}
  {{ $page := $ }}
  {{ $glossary := . }}
  {{ $set := printf "%s#glossary" $page.Permalink }}

  {{ $terms := slice }}
  {{ range $glossary.items }}
    {{/* The term and whatever it nests, so both go through the same code. */}}
    {{ $entries := slice . }}
    {{ with .items }}{{ $entries = $entries | append . }}{{ end }}
    {{ range $entries }}
      {{ $url := printf "%s#%s" $page.Permalink (or .anchor (anchorize .term)) }}
      {{ $term := dict "@type" "DefinedTerm" "@id" $url "name" .term
                       "url" $url "inDefinedTermSet" $set }}
      {{ with .description }}
        {{/* htmlUnescape because plainify removes tags but leaves entities, so
             an ampersand would otherwise be published as the literal &amp;. */}}
        {{ $text := $page.RenderString . | plainify | htmlUnescape | replaceRE `\s+` " " | strings.TrimSpace }}
        {{ with $text }}{{ $term = merge $term (dict "description" .) }}{{ end }}
      {{ end }}
      {{ with .alternateName }}{{ $term = merge $term (dict "alternateName" .) }}{{ end }}
      {{ with .sameAs }}{{ $term = merge $term (dict "sameAs" .) }}{{ end }}
      {{ with .termCode }}{{ $term = merge $term (dict "termCode" .) }}{{ end }}
      {{ $terms = $terms | append $term }}
    {{ end }}
  {{ end }}

  {{/* No terms, no set. A `definedTermSet` block carrying only a title is a
       glossary someone started and has not filled in, and an empty
       hasDefinedTerm states that the set is known to have no members. */}}
  {{ with $terms }}
    {{/* The page's own language, like head/schema-article.html, so a translated
         glossary is not read as the site's default one. `.Language.Locale` and
         not `.LanguageCode`: Hugo deprecated the `languageCode` config key in
         v0.158.0 in favour of `locale`. */}}
    {{ $d := dict "@context" "https://schema.org" "@type" "DefinedTermSet"
                  "@id" $set
                  "name" ($glossary.title | default $page.Title)
                  "url" $page.Permalink
                  "inLanguage" ($page.Language.Locale | default $page.Site.Language.Lang)
                  "hasDefinedTerm" . }}
    {{ with $glossary.description | default $page.Description }}
      {{ $d = merge $d (dict "description" .) }}
    {{ end }}
<script type="application/ld+json">
{{ $d }}
</script>
  {{ end }}
{{ end }}