PWA Network First by default

config.toml

@@ -214,7 +214,6 @@ researchgate = "your-profile-id"
 ###   online_url is used to restore the base_url after generating an Offline site.
 ###   When you set offline = true and run the npm script, the base_url is set to the absolute path on disk.
 ###   Once you set offline = false, the base_url will be set back to the value of online_url when you run the npm script again.
-
 ###############################################################################
 
 # do NOT include a trailing slash on the online URL
@@ -234,9 +233,33 @@ js_switcher_default = "dark" # default nojs switcher mode: dark, light (make sur
 search_library = 'elasticlunr'
 stylesheets = ["abridge.css"]
 
-pwa = true # true to load the service worker
 webmanifest = "manifest.min.json" # Required for PWAs
 
+###############################################################################
+### PWA (Progressive Web Application)
+### By default Abridge has pwa_NORM_TTL and pwa_LONG_TTL set to 0, this essential turns the PWA cache strategy into network first.
+###  Abridge uses cachebust hashing on js and css files, so anytime a page cache is updated, these resources would also get updated if changed.
+###  Media files rarely change, especially font files, so it is a good idea cache indefinitely.
+###  For pwa_TTL_EXEMPT indefinitely cached resources, you can force a new cache by incrementing the pwa_VER (cache version number).
+### If you would like to try a cache first strategy then set a value higher than 0 for pwa_NORM_TTL and pwa_LONG_TTL.
+###############################################################################
+
+pwa = true # true to load the service worker
+pwa_VER = '3.10.0' # Service Worker cache version. (increment if you need to force a new cache)
+
+### 3600=1hour, 28800=8hours, 86400=1day, 604800=1week, 1209600=2weeks
+pwa_NORM_TTL = 0 #  86400 is reasonable. html, json, xml, anything else undefined
+pwa_LONG_TTL = 0 # 604800 is reasonable. js, css
+
+### list of files that overrides TTL_LONG/TTL_EXEMPT to be a NORM TTL.
+pwa_TTL_NORM = '"sw.min.js", "sw_load.min.js"'
+
+### TTL_LONG file extensions will be cached for the LONG_TTL duration.
+pwa_TTL_LONG = '"jpg", "jpeg", "png", "gif", "webp", "avif", "ico", "svg", "xsl", "txt"'
+
+### TTL_EXEMPT file extensions will be cached indefinitely unless sw_load version is incremented, which would invalidate any existing cache. (and a new cache would be started)
+pwa_TTL_EXEMPT = '"js", "css", "otf", "eot", "ttf", "woff", "woff2", "mp4", "webm", "mp3", "ogg"'
+
 ###############################################################################
 ### Favicons, comment out a line to disable loading some or all of these if needed.
 ###############################################################################

package_abridge.js

@@ -24,8 +24,14 @@ const index_format = data.search.index_format;
 const uglyurls = data.extra.uglyurls;
 const offline = data.extra.offline;
 const online_url = data.extra.online_url;
+const sitePath = path.resolve('public');// used for offline builds
 const pwa = data.extra.pwa;
-const sitePath = path.resolve('public');// used for offline builds  integrity = true
+const pwa_VER = data.extra.pwa_VER;
+const pwa_NORM_TTL = data.extra.pwa_NORM_TTL;
+const pwa_LONG_TTL = data.extra.pwa_LONG_TTL;
+const pwa_TTL_NORM = data.extra.pwa_TTL_NORM;
+const pwa_TTL_LONG = data.extra.pwa_TTL_LONG;
+const pwa_TTL_EXEMPT = data.extra.pwa_TTL_EXEMPT;
 
 if (offline === false) {
   replace.sync({files: 'config.toml', from: /base_url.*=.*/g, to: "base_url=\""+online_url+"\""});
@@ -79,7 +85,7 @@ function bundle(bpath,js_prestyle,js_switcher,js_email_encode,js_copycode,search
       }
   }
   if (pwa) {
-    minify_files.push(bpath+'static/js/sw_load.js');
+    minify_files.push('static/js/sw_load.js');
   }
   return minify_files;
 }
@@ -146,10 +152,25 @@ if (search_library === 'elasticlunr') {
   // zola build && stork build --input public/data_stork/index.html --output static/stork.st
 }
 
-if (pwa) {// Update pwa file list and hashes
+if (pwa) {// Update pwa settings, file list, and hashes.
   if (!fs.existsSync('static/sw.js')) {// static/sw.js file is missing, copy from abridge theme.
     fs.copyFileSync(bpath+'static/sw.js', 'static/sw.js',fs.constants.COPYFILE_EXCL);
   }
+  if (!fs.existsSync('static/js/sw_load.js')) {// static/sw.js file is missing, copy from abridge theme.
+    fs.copyFileSync(bpath+'static/js/sw_load.js', 'static/js/sw_load.js',fs.constants.COPYFILE_EXCL);
+  }
+  // Update settings in PWA javascript file, using options parsed from config.toml.
+  if (fs.existsSync('static/js/sw_load.js')) {
+    replace.sync({files: 'static/js/sw_load.js', from: /v=.*/g, to: "v="+pwa_VER+"\","});
+  }
+  if (fs.existsSync('static/sw.js')) {
+    replace.sync({files: 'static/sw.js', from: /NORM_TTL.*=.*/g, to: "NORM_TTL = "+pwa_NORM_TTL+";"});
+    replace.sync({files: 'static/sw.js', from: /LONG_TTL.*=.*/g, to: "LONG_TTL = "+pwa_LONG_TTL+";"});
+    replace.sync({files: 'static/sw.js', from: /TTL_NORM.*=.*/g, to: "TTL_NORM = ["+pwa_TTL_NORM+"];"});
+    replace.sync({files: 'static/sw.js', from: /TTL_LONG.*=.*/g, to: "TTL_LONG = ["+pwa_TTL_LONG+"];"});
+    replace.sync({files: 'static/sw.js', from: /TTL_EXEMPT.*=.*/g, to: "TTL_EXEMPT = ["+pwa_TTL_EXEMPT+"];"});
+  }
+
   // Generate hashes for PWA BASE_CACHE_FILES
   buff = fs.readFileSync('public/abridge.css');
   const h_abridge_css = crypto.createHash('sha256').update(buff).digest('hex').slice(0,20);
@@ -212,8 +233,8 @@ if (bpath === '') {// abridge used directly
   minify(['static/js/sw_load.js']);
   minify(['static/sw.js']);
 } else if (pwa) {
-  minify([bpath+'static/js/sw_load.js']);
-  minify([bpath+'static/sw.js']);
+  minify(['static/js/sw_load.js']);
+  minify(['static/sw.js']);
 }
 
 // Minify the json manifest
@@ -228,7 +249,7 @@ if (fs.existsSync('static/manifest.json')) {// if manifest.json is present, then
 }
 
 abridge_bundle = bundle(bpath,js_prestyle,js_switcher,js_email_encode,js_copycode,search_library,index_format,uglyurls,false);
-minify(abridge_bundle,bpath+'static/js/abridge_nopwa.min.js');
+minify(abridge_bundle,'static/js/abridge_nopwa.min.js');
 
 abridge_bundle = bundle(bpath,js_prestyle,js_switcher,js_email_encode,js_copycode,search_library,index_format,uglyurls,pwa);
-minify(abridge_bundle,bpath+'static/js/abridge.min.js');
+minify(abridge_bundle,'static/js/abridge.min.js');

static/js/sw_load.js

@@ -1,6 +1,7 @@
 if ("serviceWorker" in navigator) {
     navigator.serviceWorker
-        .register("/sw.min.js?v=3.9.0", { scope: "/" })
+        .register("/sw.min.js?v=3.10.0",
+                  { scope: "/" })
         .then(() => {
             //console.info("SW Loaded");
         }, err => console.error("SW error: ", err));