Break section template into first and descendent sections

First section templates render the most recent $n yearly subsections as a list of
articles.

Descendent sections render just the content of those subsections.

i18n/en.yaml

@@ -6,3 +6,9 @@ draftNo: "NO"
 
 home: Home
 tableOfContents: Table of Contents
+
+# Title of section of a list page where years older than
+# .Site.Params.blog.yearLimit are collapsed into a bulleted list.
+olderPagesSectionTitle: Older
+
+yearsTagTitle: Years

layouts/_default/list.html

@@ -1,13 +1,7 @@
 {{ define "main" }}
-  <main class="main--list">
-    <header class="page-header">
-      {{ partial "page_header.html" (dict "page" .) }}
-    </header>
-
-    {{- .Content -}}
-
-    {{- range .Pages.ByTitle -}}
-      {{ .Render "page_summary" }}
-    {{- end -}}
-  </main>
+  {{ if eq . .FirstSection }}
+    {{ partial "page/first_section.list.html" . }}
+  {{ else }}
+    {{ partial "page/descendent_section.list.html" . }}
+  {{ end }}
 {{ end }}

layouts/blog/list.html

@@ -1,17 +1,7 @@
 {{ define "main" }}
-  <main class="main--list">
-    <header class="page-header">
-      {{ partial "page_header.html" (dict "page" .) }}
-    </header>
-
-    {{- with .Content }}
-    <div class="main__content">{{ . }}</div>
-    {{ end -}}
-
-    {{ range .Pages.ByDate.Reverse -}}
-      {{ if or (not .Draft) hugo.IsDevelopment }}
-        {{ .Render "page_summary" }}
-      {{ end }}
-    {{- end }}
-  </main>
+  {{ if eq . .FirstSection }}
+    {{ partial "page/first_section.list.html" . }}
+  {{ else }}
+    {{ partial "page/descendent_section.list.html" . }}
+  {{ end }}
 {{ end }}

layouts/partials/page/descendent_section.list.html

@@ -0,0 +1,13 @@
+<main class="main--list">
+  <header class="page-header">
+    {{ partial "page_header.html" (dict "page" .) }}
+  </header>
+
+  {{- .Content -}}
+
+  {{ range .RegularPages.ByPublishDate -}}
+    {{ if or (not .Draft) hugo.IsDevelopment -}}
+      {{ .Render "page_summary" }}
+    {{ end }}
+  {{ end }}
+</main>

layouts/partials/page/first_section.list.html

@@ -0,0 +1,39 @@
+<main class="main--list">
+  <header class="page-header">
+    {{ partial "page_header.html" (dict "page" .) }}
+  </header>
+
+  {{/* Each page is a year section. */}}
+  {{- $yearPages := .Pages.ByPublishDate.Reverse -}}
+  {{- $yearLimit := math.Max ($.Site.Params.blog.yearLimit | default 5) 3 -}}
+  {{- $expandedYears := first $yearLimit $yearPages -}}
+  {{- $collapsedYears := after $yearLimit $yearPages -}}
+
+  {{-
+    partial "page/section_year_nav.html"
+      (dict
+        "years" $expandedYears
+        "includeCollapsedYearItem" (gt (len $collapsedYears) 0)
+      )
+  -}}
+
+  {{- .Content -}}
+
+  {{ range $expandedYears -}}
+    <h2 id="{{ .Date | time.Format "2006" }}">{{ .Title }}</h2>
+    {{ range .RegularPagesRecursive.ByPublishDate.Reverse -}}
+      {{ if or (not .Draft) hugo.IsDevelopment -}}
+        {{ .Render "page_summary" }}
+      {{ end }}
+    {{ end }}
+  {{- end }}
+
+  {{ with $collapsedYears -}}
+    <h2 id="older">{{ i18n "olderPagesSectionTitle" }}</h2>
+    <ul>
+      {{ range . -}}
+        <li><a href="{{ .Permalink }}">{{ .LinkTitle | markdownify }}</a></li>
+      {{ end }}
+    </ul>
+  {{ end }}
+</main>

layouts/partials/page/section_year_nav.html

@@ -0,0 +1,13 @@
+{{- $years := .years -}}
+{{- $includeCollapsedYearItem := .includeCollapsedYearItem -}}
+<nav class="year-nav  tag">
+  <span class="tag__name">{{ i18n "yearsTagTitle" }}</span>
+  <ul class="tag__value--list">
+    {{ range $years -}}
+      <li class="tag__value__list-item"><a href="#{{ .Date | time.Format "2006" }}">{{ .LinkTitle }}</a></li>
+    {{ end }}
+    {{ if $includeCollapsedYearItem -}}
+      <li class="tag__value__list-item"><a href="#older">{{ i18n "olderPagesSectionTitle" }}</a></li>
+    {{ end }}
+  </ul>
+</nav>