From d08e17457fd739700cc2cf0dcaa660c04ec85649 Mon Sep 17 00:00:00 2001
From: Alex Shpak <alex-shpak@users.noreply.github.com>
Date: Sun, 21 Sep 2025 19:53:13 +0200
Subject: [PATCH] Add geenrated resources to be pre-cached by service worker

---
 assets/search.js                                |  2 +-
 assets/sw.js                                    |  3 +++
 exampleSite/hugo.toml                           |  2 +-
 exampleSite/hugo.yaml                           |  3 ++-
 layouts/_partials/docs/html-head.html           | 17 ++++++++++-------
 .../_partials/docs/links/resource-precache.html |  2 ++
 6 files changed, 19 insertions(+), 10 deletions(-)
 create mode 100644 layouts/_partials/docs/links/resource-precache.html

diff --git a/assets/search.js b/assets/search.js
index 91add6f..a8f7fe4 100644
--- a/assets/search.js
+++ b/assets/search.js
@@ -5,7 +5,7 @@
 {{ $searchConfig := i18n "bookSearchConfig" | default "{}" }}
 
 (function () {
-  const searchDataURL = '{{ $searchData.RelPermalink }}';
+  const searchDataURL = '{{ partial "docs/links/resource-precache" $searchData }}';
   const indexConfig = Object.assign({{ $searchConfig }}, {
     includeScore: true,
     useExtendedSearch: true,
diff --git a/assets/sw.js b/assets/sw.js
index 2ff11fc..3157db2 100644
--- a/assets/sw.js
+++ b/assets/sw.js
@@ -4,6 +4,9 @@ const pages = [
   {{ range .Site.AllPages -}}
   "{{ .RelPermalink }}",
   {{ end -}}
+  {{ range $permalink, $ok := site.Store.Get "book-sw-precache" -}}
+  "{{ $permalink }}",
+  {{ end -}}
 {{ end }}
 ];
 
diff --git a/exampleSite/hugo.toml b/exampleSite/hugo.toml
index 66d5700..6b1550a 100644
--- a/exampleSite/hugo.toml
+++ b/exampleSite/hugo.toml
@@ -139,7 +139,7 @@ enableGitInfo = true
 
   # /!\ This is an experimental feature, might be removed or changed at any time
   # (Optional, experimental, default false) Enables service worker that caches visited pages and resources for offline use.
-  BookServiceWorker = true
+  BookServiceWorker = "precache"
 
   # /!\ This is an experimental feature, might be removed or changed at any time
   # (Optional, experimental, default false) Enables a drop-down menu for translations only if a translation is present.
diff --git a/exampleSite/hugo.yaml b/exampleSite/hugo.yaml
index 4b6401a..535bd92 100644
--- a/exampleSite/hugo.yaml
+++ b/exampleSite/hugo.yaml
@@ -124,7 +124,8 @@ params:
 
   # /!\ This is an experimental feature, might be removed or changed at any time
   # (Optional, experimental, default false) Enables service worker that caches visited pages and resources for offline use.
-  BookServiceWorker: true
+  # can be false, true or 'precache', precache will try to download all content pages on install.
+  BookServiceWorker: 'precache'
 
   # /!\ This is an experimental feature, might be removed or changed at any time
   # (Optional, experimental, default false) Enables a drop-down menu for translations only if a translation is present.
diff --git a/layouts/_partials/docs/html-head.html b/layouts/_partials/docs/html-head.html
index 6a6d0ec..58c8774 100644
--- a/layouts/_partials/docs/html-head.html
+++ b/layouts/_partials/docs/html-head.html
@@ -1,3 +1,8 @@
+{{ "<!--" | safeHTML }}
+Made with Book Theme
+https://github.com/alex-shpak/hugo-book
+{{ "-->" | safeHTML }}
+
 <meta charset="UTF-8">
 <meta name="viewport" content="width=device-width, initial-scale=1.0">
 <meta name="description" content="{{ default .Summary .Description }}">
@@ -24,14 +29,17 @@
 
 <!-- Theme stylesheet, you can customize scss by creating `assets/custom.scss` in your website -->
 {{- $styles := resources.Get "book.scss" | resources.ExecuteAsTemplate "book.scss" . | css.Sass | resources.Minify | resources.Fingerprint }}
-<link rel="stylesheet" href="{{ $styles.RelPermalink }}" {{ template "integrity" $styles }}>
+<link rel="stylesheet" href="{{ partial "docs/links/resource-precache" $styles }}" {{ template "integrity" $styles }}>
+
+<!-- Search -->
 {{- if default true .Site.Params.BookSearch -}}
   {{- $searchJSFile := printf "%s.search.js" .Language.Lang }}
   {{- $searchJS := resources.Get "search.js" | resources.ExecuteAsTemplate $searchJSFile . | resources.Minify | resources.Fingerprint }}
   <script defer src="{{ "fuse.min.js" | relURL }}"></script>
-  <script defer src="{{ $searchJS.RelPermalink }}" {{ template "integrity" $searchJS }}></script>
+  <script defer src="{{ partial "docs/links/resource-precache" $searchJS }}" {{ template "integrity" $searchJS }}></script>
 {{ end -}}
 
+<!-- Service Worker -->
 {{- if .Site.Params.BookServiceWorker -}}
   {{- $swJS := resources.Get "sw-register.js" | resources.ExecuteAsTemplate "sw.js" . | resources.Minify | resources.Fingerprint }}
   <script defer src="{{ $swJS.RelPermalink }}" {{ template "integrity" $swJS }}></script>
@@ -44,11 +52,6 @@
   {{ printf `<link rel="%s" type="%s" href="%s" title="%s" />` .Rel .MediaType.Type .Permalink $.Site.Title | safeHTML }}
 {{ end -}}
 
-{{ "<!--" | safeHTML }}
-Made with Book Theme
-https://github.com/alex-shpak/hugo-book
-{{ "-->" | safeHTML }}
-
 {{- define "integrity" -}}
   {{- if (urls.Parse .Permalink).Host -}}
     integrity="{{ .Data.Integrity }}" crossorigin="anonymous"
diff --git a/layouts/_partials/docs/links/resource-precache.html b/layouts/_partials/docs/links/resource-precache.html
new file mode 100644
index 0000000..e254a38
--- /dev/null
+++ b/layouts/_partials/docs/links/resource-precache.html
@@ -0,0 +1,2 @@
+{{- site.Store.SetInMap "book-sw-precache" .RelPermalink true -}}
+{{- return .RelPermalink -}}
\ No newline at end of file