tpl: Add a terse pagination template variant to improve performance

These calls are equivalent:

{{ template "_internal/pagination.html" . }}
{{ template "_internal/pagination.html" (dict "page" .) }}
{{ template "_internal/pagination.html" (dict "page" . "format" "default") }}

To use an alternate format:

{{ template "_internal/pagination.html" (dict "page" . "format" "terse") }}

Fixes #8599

hugolib/embedded_templates_test.go

@@ -116,3 +116,42 @@ Disqus:
 	// Disqus
 	b.AssertFileContent("public/index.html", "\"disqus_shortname\" + '.disqus.com/embed.js';")
 }
+
+func TestEmbeddedPaginationTemplate(t *testing.T) {
+	t.Parallel()
+
+	test := func(variant string, expectedOutput string) {
+		b := newTestSitesBuilder(t)
+		b.WithConfigFile("toml", `paginate = 1`)
+		b.WithContent(
+			"s1/p01.md", "---\ntitle: p01\n---",
+			"s1/p02.md", "---\ntitle: p02\n---",
+			"s1/p03.md", "---\ntitle: p03\n---",
+			"s1/p04.md", "---\ntitle: p04\n---",
+			"s1/p05.md", "---\ntitle: p05\n---",
+			"s1/p06.md", "---\ntitle: p06\n---",
+			"s1/p07.md", "---\ntitle: p07\n---",
+			"s1/p08.md", "---\ntitle: p08\n---",
+			"s1/p09.md", "---\ntitle: p09\n---",
+			"s1/p10.md", "---\ntitle: p10\n---",
+		)
+		b.WithTemplates("index.html", `{{ .Paginate (where site.RegularPages "Section" "s1") }}`+variant)
+		b.Build(BuildCfg{})
+		b.AssertFileContent("public/index.html", expectedOutput)
+	}
+
+	expectedOutputDefaultFormat := "Pager 1\n    <ul class=\"pagination pagination-default\">\n      <li class=\"page-item disabled\">\n        <a href=\"#\" aria-disabled=\"true\" aria-label=\"First\" class=\"page-link\" role=\"button\"><span aria-hidden=\"true\">&laquo;&laquo;</span></a>\n      </li>\n      <li class=\"page-item disabled\">\n        <a href=\"#\" aria-disabled=\"true\" aria-label=\"Previous\" class=\"page-link\" role=\"button\"><span aria-hidden=\"true\">&laquo;</span></a>\n      </li>\n      <li class=\"page-item active\">\n        <a href=\"#\" aria-current=\"page\" aria-label=\"Page 1\" class=\"page-link\" role=\"button\">1</a>\n      </li>\n      <li class=\"page-item\">\n        <a href=\"/page/2/\" aria-label=\"Page 2\" class=\"page-link\" role=\"button\">2</a>\n      </li>\n      <li class=\"page-item\">\n        <a href=\"/page/3/\" aria-label=\"Page 3\" class=\"page-link\" role=\"button\">3</a>\n      </li>\n      <li class=\"page-item\">\n        <a href=\"/page/4/\" aria-label=\"Page 4\" class=\"page-link\" role=\"button\">4</a>\n      </li>\n      <li class=\"page-item\">\n        <a href=\"/page/5/\" aria-label=\"Page 5\" class=\"page-link\" role=\"button\">5</a>\n      </li>\n      <li class=\"page-item\">\n        <a href=\"/page/2/\" aria-label=\"Next\" class=\"page-link\" role=\"button\"><span aria-hidden=\"true\">&raquo;</span></a>\n      </li>\n      <li class=\"page-item\">\n        <a href=\"/page/10/\" aria-label=\"Last\" class=\"page-link\" role=\"button\"><span aria-hidden=\"true\">&raquo;&raquo;</span></a>\n      </li>\n    </ul>"
+	expectedOutputTerseFormat := "Pager 1\n    <ul class=\"pagination pagination-terse\">\n      <li class=\"page-item active\">\n        <a href=\"#\" aria-current=\"page\" aria-label=\"Page 1\" class=\"page-link\" role=\"button\">1</a>\n      </li>\n      <li class=\"page-item\">\n        <a href=\"/page/2/\" aria-label=\"Page 2\" class=\"page-link\" role=\"button\">2</a>\n      </li>\n      <li class=\"page-item\">\n        <a href=\"/page/3/\" aria-label=\"Page 3\" class=\"page-link\" role=\"button\">3</a>\n      </li>\n      <li class=\"page-item\">\n        <a href=\"/page/2/\" aria-label=\"Next\" class=\"page-link\" role=\"button\"><span aria-hidden=\"true\">&raquo;</span></a>\n      </li>\n      <li class=\"page-item\">\n        <a href=\"/page/10/\" aria-label=\"Last\" class=\"page-link\" role=\"button\"><span aria-hidden=\"true\">&raquo;&raquo;</span></a>\n      </li>\n    </ul>"
+
+	variant := `{{ template "_internal/pagination.html" . }}`
+	test(variant, expectedOutputDefaultFormat)
+
+	variant = `{{ template "_internal/pagination.html" (dict "page" .) }}`
+	test(variant, expectedOutputDefaultFormat)
+
+	variant = `{{ template "_internal/pagination.html" (dict "page" . "format" "default") }}`
+	test(variant, expectedOutputDefaultFormat)
+
+	variant = `{{ template "_internal/pagination.html" (dict "page" . "format" "terse") }}`
+	test(variant, expectedOutputTerseFormat)
+}

tpl/tplimpl/embedded/templates.autogen.go

@@ -248,51 +248,160 @@ if (!doNotTrack) {
 {{- /* Facebook Page Admin ID for Domain Insights */}}
 {{- with .Site.Social.facebook_admin }}<meta property="fb:admins" content="{{ . }}" />{{ end }}
 `},
-	{`pagination.html`, `{{ $pag := $.Paginator }}
+	{`pagination.html`, `{{- $validFormats := slice "default" "terse" }}
-{{ if gt $pag.TotalPages 1 -}}
+
-<ul class="pagination">
+{{- $msg1 := "When passing a map to the internal pagination template, one of the elements must be named 'page', and it must be set to the context of the current page." }}
-  {{ with $pag.First -}}
+{{- $msg2 := "The 'format' specified in the map passed to the internal pagination template is invalid. Valid choices are: %s." }}
-  <li class="page-item">
+
-    <a href="{{ .URL }}" class="page-link" aria-label="First"><span aria-hidden="true">&laquo;&laquo;</span></a>
+{{- $page := . }}
-  </li>
+{{- $format := "default" }}
-  {{ end -}}
+
-  <li class="page-item{{ if not $pag.HasPrev }} disabled{{ end }}">
+{{- if reflect.IsMap . }}
-    <a {{ if $pag.HasPrev }}href="{{ $pag.Prev.URL }}"{{ end }} class="page-link" aria-label="Previous"><span aria-hidden="true">&laquo;</span></a>
+  {{- with .page }}
-  </li>
+    {{- $page = . }}
-  {{- $ellipsed := false -}}
+  {{- else }}
-  {{- $shouldEllipse := false -}}
+    {{- errorf $msg1 }}
-  {{- range $pag.Pagers -}}
-  {{- $right := sub .TotalPages .PageNumber -}}
-  {{- $showNumber := or (le .PageNumber 3) (eq $right 0) -}}
-  {{- $showNumber := or $showNumber (le .TotalPages 5) -}}{{/* Issue #7523 */}}
-  {{- $showNumber := or $showNumber (and (gt .PageNumber (sub $pag.PageNumber 2)) (lt .PageNumber (add $pag.PageNumber 2))) -}}
-  {{- if $showNumber -}}
-    {{- $ellipsed = false -}}
-    {{- $shouldEllipse = false -}}
-  {{- else -}}
-    {{- $shouldEllipse = not $ellipsed -}}
-    {{- $ellipsed = true -}}
-  {{- end -}}
-  {{- if $showNumber }}
-  <li class="page-item{{ if eq . $pag }} active{{ end }}">
-    <a class="page-link" href="{{ .URL }}">{{ .PageNumber }}</a>
-  </li>
-  {{- else if $shouldEllipse }}
-  <li class="page-item disabled">
-    <span aria-hidden="true">&nbsp;&hellip;&nbsp;</span>
-  </li>
-  {{- end -}}
   {{- end }}
-  <li class="page-item{{ if not $pag.HasNext }} disabled{{ end }}">
+  {{- with .format }}
-    <a {{ if $pag.HasNext }}href="{{ $pag.Next.URL }}"{{ end }} class="page-link" aria-label="Next"><span aria-hidden="true">&raquo;</span></a>
+    {{- $format = lower . }}
-  </li>
-  {{- with $pag.Last }}
-  <li class="page-item">
-    <a href="{{ .URL }}" class="page-link" aria-label="Last"><span aria-hidden="true">&raquo;&raquo;</span></a>
-  </li>
   {{- end }}
+{{- end }}
+
+{{- if in $validFormats $format }}
+  {{- if gt $page.Paginator.TotalPages 1 }}
+    <ul class="pagination pagination-{{ $format }}">
+      {{- partial (printf "partials/inline/pagination/%s" $format) $page }}
     </ul>
-{{ end }}
+  {{- end }}
+{{- else }}
+  {{- errorf $msg2 (delimit $validFormats ", ") }}
+{{- end -}}
+
+{{/* Format: default
+{{/* --------------------------------------------------------------------- */}}
+{{- define "partials/inline/pagination/default" }}
+  {{- with .Paginator }}
+    {{- $currentPageNumber := .PageNumber }}
+
+    {{- with .First }}
+      {{- if ne $currentPageNumber .PageNumber }}
+      <li class="page-item">
+        <a href="{{ .URL }}" aria-label="First" class="page-link" role="button"><span aria-hidden="true">&laquo;&laquo;</span></a>
+      </li>
+      {{- else }}
+      <li class="page-item disabled">
+        <a href="#" aria-disabled="true" aria-label="First" class="page-link" role="button"><span aria-hidden="true">&laquo;&laquo;</span></a>
+      </li>
+      {{- end }}
+    {{- end }}
+
+    {{- with .Prev }}
+      <li class="page-item">
+        <a href="{{ .URL }}" aria-label="Previous" class="page-link" role="button"><span aria-hidden="true">&laquo;</span></a>
+      </li>
+    {{- else }}
+      <li class="page-item disabled">
+        <a href="#" aria-disabled="true" aria-label="Previous" class="page-link" role="button"><span aria-hidden="true">&laquo;</span></a>
+      </li>
+    {{- end }}
+
+    {{- $slots := 5 }}
+    {{- $start := math.Max 1 (sub .PageNumber (math.Floor (div $slots 2))) }}
+    {{- $end := math.Min .TotalPages (sub (add $start $slots) 1) }}
+    {{- if lt (add (sub $end $start) 1) $slots }}
+      {{- $start = math.Max 1 (add (sub $end $slots) 1) }}
+    {{- end }}
+
+    {{- range $k := seq $start $end }}
+      {{- if eq $.Paginator.PageNumber $k }}
+      <li class="page-item active">
+        <a href="#" aria-current="page" aria-label="Page {{ $k }}" class="page-link" role="button">{{ $k }}</a>
+      </li>
+      {{- else }}
+      <li class="page-item">
+        <a href="{{ (index $.Paginator.Pagers (sub $k 1)).URL }}" aria-label="Page {{ $k }}" class="page-link" role="button">{{ $k }}</a>
+      </li>
+      {{- end }}
+    {{- end }}
+
+    {{- with .Next }}
+      <li class="page-item">
+        <a href="{{ .URL }}" aria-label="Next" class="page-link" role="button"><span aria-hidden="true">&raquo;</span></a>
+      </li>
+    {{- else }}
+      <li class="page-item disabled">
+        <a href="#" aria-disabled="true" aria-label="Next" class="page-link" role="button"><span aria-hidden="true">&raquo;</span></a>
+      </li>
+    {{- end }}
+
+    {{- with .Last }}
+      {{- if ne $currentPageNumber .PageNumber }}
+      <li class="page-item">
+        <a href="{{ .URL }}" aria-label="Last" class="page-link" role="button"><span aria-hidden="true">&raquo;&raquo;</span></a>
+      </li>
+      {{- else }}
+      <li class="page-item disabled">
+        <a href="#" aria-disabled="true" aria-label="Last" class="page-link" role="button"><span aria-hidden="true">&raquo;&raquo;</span></a>
+      </li>
+      {{- end }}
+    {{- end }}
+  {{- end }}
+{{- end -}}
+
+{{/* Format: terse
+{{/* --------------------------------------------------------------------- */}}
+{{- define "partials/inline/pagination/terse" }}
+  {{- with .Paginator }}
+    {{- $currentPageNumber := .PageNumber }}
+
+    {{- with .First }}
+      {{- if ne $currentPageNumber .PageNumber }}
+      <li class="page-item">
+        <a href="{{ .URL }}" aria-label="First" class="page-link" role="button"><span aria-hidden="true">&laquo;&laquo;</span></a>
+      </li>
+      {{- end }}
+    {{- end }}
+
+    {{- with .Prev }}
+      <li class="page-item">
+        <a href="{{ .URL }}" aria-label="Previous" class="page-link" role="button"><span aria-hidden="true">&laquo;</span></a>
+      </li>
+    {{- end }}
+
+    {{- $slots := 3 }}
+    {{- $start := math.Max 1 (sub .PageNumber (math.Floor (div $slots 2))) }}
+    {{- $end := math.Min .TotalPages (sub (add $start $slots) 1) }}
+    {{- if lt (add (sub $end $start) 1) $slots }}
+      {{- $start = math.Max 1 (add (sub $end $slots) 1) }}
+    {{- end }}
+
+    {{- range $k := seq $start $end }}
+      {{- if eq $.Paginator.PageNumber $k }}
+      <li class="page-item active">
+        <a href="#" aria-current="page" aria-label="Page {{ $k }}" class="page-link" role="button">{{ $k }}</a>
+      </li>
+      {{- else }}
+      <li class="page-item">
+        <a href="{{ (index $.Paginator.Pagers (sub $k 1)).URL }}" aria-label="Page {{ $k }}" class="page-link" role="button">{{ $k }}</a>
+      </li>
+      {{- end }}
+    {{- end }}
+
+    {{- with .Next }}
+      <li class="page-item">
+        <a href="{{ .URL }}" aria-label="Next" class="page-link" role="button"><span aria-hidden="true">&raquo;</span></a>
+      </li>
+    {{- end }}
+
+    {{- with .Last }}
+      {{- if ne $currentPageNumber .PageNumber }}
+      <li class="page-item">
+        <a href="{{ .URL }}" aria-label="Last" class="page-link" role="button"><span aria-hidden="true">&raquo;&raquo;</span></a>
+      </li>
+      {{- end }}
+    {{- end }}
+  {{- end }}
+{{- end -}}
 `},
 	{`schema.html`, `<meta itemprop="name" content="{{ .Title }}">
 <meta itemprop="description" content="{{ with .Description }}{{ . }}{{ else }}{{if .IsPage}}{{ .Summary }}{{ else }}{{ with .Site.Params.description }}{{ . }}{{ end }}{{ end }}{{ end }}">

tpl/tplimpl/embedded/templates/pagination.html

@@ -1,45 +1,154 @@
-{{ $pag := $.Paginator }}
+{{- $validFormats := slice "default" "terse" }}
-{{ if gt $pag.TotalPages 1 -}}
+
-<ul class="pagination">
+{{- $msg1 := "When passing a map to the internal pagination template, one of the elements must be named 'page', and it must be set to the context of the current page." }}
-  {{ with $pag.First -}}
+{{- $msg2 := "The 'format' specified in the map passed to the internal pagination template is invalid. Valid choices are: %s." }}
-  <li class="page-item">
+
-    <a href="{{ .URL }}" class="page-link" aria-label="First"><span aria-hidden="true">&laquo;&laquo;</span></a>
+{{- $page := . }}
-  </li>
+{{- $format := "default" }}
-  {{ end -}}
+
-  <li class="page-item{{ if not $pag.HasPrev }} disabled{{ end }}">
+{{- if reflect.IsMap . }}
-    <a {{ if $pag.HasPrev }}href="{{ $pag.Prev.URL }}"{{ end }} class="page-link" aria-label="Previous"><span aria-hidden="true">&laquo;</span></a>
+  {{- with .page }}
-  </li>
+    {{- $page = . }}
-  {{- $ellipsed := false -}}
+  {{- else }}
-  {{- $shouldEllipse := false -}}
+    {{- errorf $msg1 }}
-  {{- range $pag.Pagers -}}
-  {{- $right := sub .TotalPages .PageNumber -}}
-  {{- $showNumber := or (le .PageNumber 3) (eq $right 0) -}}
-  {{- $showNumber := or $showNumber (le .TotalPages 5) -}}{{/* Issue #7523 */}}
-  {{- $showNumber := or $showNumber (and (gt .PageNumber (sub $pag.PageNumber 2)) (lt .PageNumber (add $pag.PageNumber 2))) -}}
-  {{- if $showNumber -}}
-    {{- $ellipsed = false -}}
-    {{- $shouldEllipse = false -}}
-  {{- else -}}
-    {{- $shouldEllipse = not $ellipsed -}}
-    {{- $ellipsed = true -}}
-  {{- end -}}
-  {{- if $showNumber }}
-  <li class="page-item{{ if eq . $pag }} active{{ end }}">
-    <a class="page-link" href="{{ .URL }}">{{ .PageNumber }}</a>
-  </li>
-  {{- else if $shouldEllipse }}
-  <li class="page-item disabled">
-    <span aria-hidden="true">&nbsp;&hellip;&nbsp;</span>
-  </li>
-  {{- end -}}
   {{- end }}
-  <li class="page-item{{ if not $pag.HasNext }} disabled{{ end }}">
+  {{- with .format }}
-    <a {{ if $pag.HasNext }}href="{{ $pag.Next.URL }}"{{ end }} class="page-link" aria-label="Next"><span aria-hidden="true">&raquo;</span></a>
+    {{- $format = lower . }}
-  </li>
-  {{- with $pag.Last }}
-  <li class="page-item">
-    <a href="{{ .URL }}" class="page-link" aria-label="Last"><span aria-hidden="true">&raquo;&raquo;</span></a>
-  </li>
   {{- end }}
+{{- end }}
+
+{{- if in $validFormats $format }}
+  {{- if gt $page.Paginator.TotalPages 1 }}
+    <ul class="pagination pagination-{{ $format }}">
+      {{- partial (printf "partials/inline/pagination/%s" $format) $page }}
     </ul>
-{{ end }}
+  {{- end }}
+{{- else }}
+  {{- errorf $msg2 (delimit $validFormats ", ") }}
+{{- end -}}
+
+{{/* Format: default
+{{/* --------------------------------------------------------------------- */}}
+{{- define "partials/inline/pagination/default" }}
+  {{- with .Paginator }}
+    {{- $currentPageNumber := .PageNumber }}
+
+    {{- with .First }}
+      {{- if ne $currentPageNumber .PageNumber }}
+      <li class="page-item">
+        <a href="{{ .URL }}" aria-label="First" class="page-link" role="button"><span aria-hidden="true">&laquo;&laquo;</span></a>
+      </li>
+      {{- else }}
+      <li class="page-item disabled">
+        <a href="#" aria-disabled="true" aria-label="First" class="page-link" role="button"><span aria-hidden="true">&laquo;&laquo;</span></a>
+      </li>
+      {{- end }}
+    {{- end }}
+
+    {{- with .Prev }}
+      <li class="page-item">
+        <a href="{{ .URL }}" aria-label="Previous" class="page-link" role="button"><span aria-hidden="true">&laquo;</span></a>
+      </li>
+    {{- else }}
+      <li class="page-item disabled">
+        <a href="#" aria-disabled="true" aria-label="Previous" class="page-link" role="button"><span aria-hidden="true">&laquo;</span></a>
+      </li>
+    {{- end }}
+
+    {{- $slots := 5 }}
+    {{- $start := math.Max 1 (sub .PageNumber (math.Floor (div $slots 2))) }}
+    {{- $end := math.Min .TotalPages (sub (add $start $slots) 1) }}
+    {{- if lt (add (sub $end $start) 1) $slots }}
+      {{- $start = math.Max 1 (add (sub $end $slots) 1) }}
+    {{- end }}
+
+    {{- range $k := seq $start $end }}
+      {{- if eq $.Paginator.PageNumber $k }}
+      <li class="page-item active">
+        <a href="#" aria-current="page" aria-label="Page {{ $k }}" class="page-link" role="button">{{ $k }}</a>
+      </li>
+      {{- else }}
+      <li class="page-item">
+        <a href="{{ (index $.Paginator.Pagers (sub $k 1)).URL }}" aria-label="Page {{ $k }}" class="page-link" role="button">{{ $k }}</a>
+      </li>
+      {{- end }}
+    {{- end }}
+
+    {{- with .Next }}
+      <li class="page-item">
+        <a href="{{ .URL }}" aria-label="Next" class="page-link" role="button"><span aria-hidden="true">&raquo;</span></a>
+      </li>
+    {{- else }}
+      <li class="page-item disabled">
+        <a href="#" aria-disabled="true" aria-label="Next" class="page-link" role="button"><span aria-hidden="true">&raquo;</span></a>
+      </li>
+    {{- end }}
+
+    {{- with .Last }}
+      {{- if ne $currentPageNumber .PageNumber }}
+      <li class="page-item">
+        <a href="{{ .URL }}" aria-label="Last" class="page-link" role="button"><span aria-hidden="true">&raquo;&raquo;</span></a>
+      </li>
+      {{- else }}
+      <li class="page-item disabled">
+        <a href="#" aria-disabled="true" aria-label="Last" class="page-link" role="button"><span aria-hidden="true">&raquo;&raquo;</span></a>
+      </li>
+      {{- end }}
+    {{- end }}
+  {{- end }}
+{{- end -}}
+
+{{/* Format: terse
+{{/* --------------------------------------------------------------------- */}}
+{{- define "partials/inline/pagination/terse" }}
+  {{- with .Paginator }}
+    {{- $currentPageNumber := .PageNumber }}
+
+    {{- with .First }}
+      {{- if ne $currentPageNumber .PageNumber }}
+      <li class="page-item">
+        <a href="{{ .URL }}" aria-label="First" class="page-link" role="button"><span aria-hidden="true">&laquo;&laquo;</span></a>
+      </li>
+      {{- end }}
+    {{- end }}
+
+    {{- with .Prev }}
+      <li class="page-item">
+        <a href="{{ .URL }}" aria-label="Previous" class="page-link" role="button"><span aria-hidden="true">&laquo;</span></a>
+      </li>
+    {{- end }}
+
+    {{- $slots := 3 }}
+    {{- $start := math.Max 1 (sub .PageNumber (math.Floor (div $slots 2))) }}
+    {{- $end := math.Min .TotalPages (sub (add $start $slots) 1) }}
+    {{- if lt (add (sub $end $start) 1) $slots }}
+      {{- $start = math.Max 1 (add (sub $end $slots) 1) }}
+    {{- end }}
+
+    {{- range $k := seq $start $end }}
+      {{- if eq $.Paginator.PageNumber $k }}
+      <li class="page-item active">
+        <a href="#" aria-current="page" aria-label="Page {{ $k }}" class="page-link" role="button">{{ $k }}</a>
+      </li>
+      {{- else }}
+      <li class="page-item">
+        <a href="{{ (index $.Paginator.Pagers (sub $k 1)).URL }}" aria-label="Page {{ $k }}" class="page-link" role="button">{{ $k }}</a>
+      </li>
+      {{- end }}
+    {{- end }}
+
+    {{- with .Next }}
+      <li class="page-item">
+        <a href="{{ .URL }}" aria-label="Next" class="page-link" role="button"><span aria-hidden="true">&raquo;</span></a>
+      </li>
+    {{- end }}
+
+    {{- with .Last }}
+      {{- if ne $currentPageNumber .PageNumber }}
+      <li class="page-item">
+        <a href="{{ .URL }}" aria-label="Last" class="page-link" role="button"><span aria-hidden="true">&raquo;&raquo;</span></a>
+      </li>
+      {{- end }}
+    {{- end }}
+  {{- end }}
+{{- end -}}