feat(json-ld): add support for FAQs structure (#27)

fix(json-ld): correct page context and transform structure template name

modules/json-ld/layouts/partials/seo/modules/json-ld/index.html

@@ -2,9 +2,10 @@
   {{- partial "seo/modules/json-ld/append" (dict "page" . "structure" "website") }}
 {{- end }}
 {{- $params := default dict .Params.json_ld }}
-{{- $structures := slice "news-article" }}
+{{- $structures := slice "news_article" "faq_page" }}
+{{- $page := . }}
 {{- range $structures }}
   {{- if isset $params . }}
-    {{- partial "seo/modules/json-ld/append" (dict "page" . "structure" .) }}
+    {{- partial "seo/modules/json-ld/append" (dict "page" $page "structure" (replace . "_" "-")) }}
   {{- end }}
 {{- end }}

modules/json-ld/layouts/partials/seo/modules/json-ld/script.html

@@ -1,9 +1,10 @@
 {{- with .Store.Get "seo-json-ld" }}
-  {{- $json := . }}
+  {{- $structures := sort . }}
+  {{- $json := "" }}
   {{- if eq (len .) 1 }}
-    {{- $json = jsonify (index (sort .) 0) }}
+    {{- $json = jsonify (index $structures 0) }}
   {{- else }}
-    {{- $json = jsonify . }}
+    {{- $json = jsonify $structures }}
   {{- end }}
   {{- $json | printf `<script type="application/ld+json">%s</script>` | safeHTML }}
 {{- end -}}

modules/json-ld/layouts/partials/seo/modules/json-ld/structures/faq-page.html

@@ -0,0 +1,34 @@
+{{- $s := newScratch }}
+{{- $s.Set "@context" "https://schema.org" }}
+{{- $s.Set "@type" "FAQPage" }}
+{{- $params := default dict .Params.json_ld.faq_page }}
+{{- $data := default "" $params.data }}
+{{- $questionField := default "question" $params.question_field }}
+{{- $answerField := default "answer" $params.answer_field }}
+{{- $questions := slice }}
+{{- with index site.Data $data }}
+  {{- range . }}
+    {{- $question := "" }}
+    {{- $answer := "" }}
+    {{- with index . $questionField }}
+      {{- $question = . }}
+    {{- else }}
+      {{- warnf "[seo|json-ld/faq] no such question field in %q data: %s" $data $questionField }}
+      {{- continue }}
+    {{- end }}
+    {{- with index . $answerField }}
+      {{- $answer = . | $.RenderString }}
+    {{- else }}
+      {{- warnf "[seo/json-ld/faq] no such answer field in %q data: %s" $data $questionField }}
+      {{- continue }}
+    {{- end }}
+    {{- $s.Add "mainEntity" (slice (dict
+      "@type" "Question"
+      "name" $question
+      "acceptedAnswer" (dict "@type" "Answer" "text" $answer)))
+    }}
+  {{- end }}
+{{- else }}
+  {{- warnf "[seo/json-ld/faq] no such FAQs data: %q" $data }}
+{{- end }}
+{{- return $s.Values }}