Merge pull request #57718 from Faless/js/4.x_pwa_prefer_cache_pr

13 files changed, 264 insertions, 66 deletions

diff --git a/doc/classes/JavaScript.xml b/doc/classes/JavaScript.xml
index aeaf8ac1f5..4ea60ad867 100644
--- a/doc/classes/JavaScript.xml
+++ b/doc/classes/JavaScript.xml
@@ -53,5 +53,27 @@
 				Returns an interface to a JavaScript object that can be used by scripts. The [code]interface[/code] must be a valid property of the JavaScript [code]window[/code]. The callback must accept a single [Array] argument, which will contain the JavaScript [code]arguments[/code]. See [JavaScriptObject] for usage.
 			</description>
 		</method>
+		<method name="pwa_needs_update" qualifiers="const">
+			<return type="bool" />
+			<description>
+				Returns [code]true[/code] if a new version of the progressive web app is waiting to be activated.
+				[b]Note:[/b] Only relevant when exported as a Progressive Web App.
+			</description>
+		</method>
+		<method name="pwa_update">
+			<return type="int" enum="Error" />
+			<description>
+				Performs the live update of the progressive web app. Forcing the new version to be installed and the page to be reloaded.
+				[b]Note:[/b] Your application will be [b]reloaded in all browser tabs[/b].
+				[b]Note:[/b] Only relevant when exported as a Progressive Web App and [method pwa_needs_update] returns [code]true[/code].
+			</description>
+		</method>
 	</methods>
+	<signals>
+		<signal name="pwa_update_available">
+			<description>
+				Emitted when an update for this progressive web app has been detected but is waiting to be activated because a previous version is active. See [method pwa_update] to force the update to take place immediately.
+			</description>
+		</signal>
+	</signals>
 </class>
diff --git a/misc/dist/html/editor.html b/misc/dist/html/editor.html
index a681a2a1c3..9e03f50c37 100644
--- a/misc/dist/html/editor.html
+++ b/misc/dist/html/editor.html
@@ -265,6 +265,7 @@
 		<button id="btn-close-editor" class="btn close-btn" disabled="disabled" onclick="closeEditor()">×</button>
 		<button id="btn-tab-game" class="btn tab-btn" disabled="disabled" onclick="showTab('game')">Game</button>
 		<button id="btn-close-game" class="btn close-btn"  disabled="disabled" onclick="closeGame()">×</button>
+		<button id="btn-tab-update" class="btn tab-btn" style="display: none;">Update</button>
 	</div>
 	<div id="tabs">
 		<div id="tab-loader">
@@ -324,10 +325,39 @@
 			<div id="status-notice" class="godot" style="display: none;"></div>
 		</div>
 	</div>
-	<script>
+	<script>//<![CDATA[
 		window.addEventListener("load", () => {
+			function notifyUpdate(sw) {
+				const btn = document.getElementById("btn-tab-update");
+				btn.onclick = function () {
+					if (!window.confirm("Are you sure you want to update?\nClicking \"OK\" will reload all active instances!")) {
+						return;
+					}
+					sw.postMessage("update");
+					btn.innerHTML = "Updating...";
+					btn.disabled = true;
+				};
+				btn.style.display = "";
+			}
 			if ("serviceWorker" in navigator) {
-				navigator.serviceWorker.register("service.worker.js");
+				navigator.serviceWorker.register("service.worker.js").then(function (reg) {
+					if (reg.waiting) {
+						notifyUpdate(reg.waiting);
+					}
+					reg.addEventListener("updatefound", function () {
+						const update = reg.installing;
+						update.addEventListener("statechange", function () {
+							if (update.state === "installed") {
+								// It's a new install, claim and perform aggressive caching.
+								if (!reg.active) {
+									update.postMessage("claim");
+								} else {
+									notifyUpdate(update);
+								}
+							}
+						});
+					});
+				});
 			}
 
 			if (localStorage.getItem("welcomeModalDismissed") !== 'true') {
@@ -342,7 +372,7 @@
 				localStorage.setItem("welcomeModalDismissed", 'true');
 			}
 		}
-	</script>
+	//]]></script>
 	<script src="godot.tools.js"></script>
 	<script>//<![CDATA[
 
diff --git a/misc/dist/html/service-worker.js b/misc/dist/html/service-worker.js
index 063e40a6cb..310574f21d 100644
--- a/misc/dist/html/service-worker.js
+++ b/misc/dist/html/service-worker.js
@@ -4,7 +4,8 @@
 // Incrementing CACHE_VERSION will kick off the install event and force
 // previously cached resources to be updated from the network.
 const CACHE_VERSION = "@GODOT_VERSION@";
-const CACHE_NAME = "@GODOT_NAME@-cache";
+const CACHE_PREFIX = "@GODOT_NAME@-sw-cache-";
+const CACHE_NAME = CACHE_PREFIX + CACHE_VERSION;
 const OFFLINE_URL = "@GODOT_OFFLINE_PAGE@";
 // Files that will be cached on load.
 const CACHED_FILES = @GODOT_CACHE@;
@@ -13,26 +14,35 @@ const CACHABLE_FILES = @GODOT_OPT_CACHE@;
 const FULL_CACHE = CACHED_FILES.concat(CACHABLE_FILES);
 
 self.addEventListener("install", (event) => {
-	event.waitUntil(async function () {
-		const cache = await caches.open(CACHE_NAME);
-		// Clear old cache (including optionals).
-		await Promise.all(FULL_CACHE.map(path => cache.delete(path)));
-		// Insert new one.
-		const done = await cache.addAll(CACHED_FILES);
-		return done;
-	}());
+	event.waitUntil(caches.open(CACHE_NAME).then(cache => cache.addAll(CACHED_FILES)));
 });
 
 self.addEventListener("activate", (event) => {
-	event.waitUntil(async function () {
-		if ("navigationPreload" in self.registration) {
-			await self.registration.navigationPreload.enable();
-		}
-	}());
-	// Tell the active service worker to take control of the page immediately.
-	self.clients.claim();
+	event.waitUntil(caches.keys().then(
+		function (keys) {
+			// Remove old caches.
+			return Promise.all(keys.filter(key => key.startsWith(CACHE_PREFIX) && key != CACHE_NAME).map(key => caches.delete(key)));
+		}).then(function() {
+			// Enable navigation preload if available.
+			return ("navigationPreload" in self.registration) ? self.registration.navigationPreload.enable() : Promise.resolve();
+		})
+	);
 });
 
+async function fetchAndCache(event, cache, isCachable) {
+	// Use the preloaded response, if it's there
+	let response = await event.preloadResponse;
+	if (!response) {
+		// Or, go over network.
+		response = await self.fetch(event.request);
+	}
+	if (isCachable) {
+		// And update the cache
+		cache.put(event.request, response.clone());
+	}
+	return response;
+}
+
 self.addEventListener("fetch", (event) => {
 	const isNavigate = event.request.mode === "navigate";
 	const url = event.request.url || "";
@@ -42,32 +52,54 @@ self.addEventListener("fetch", (event) => {
 	const isCachable = FULL_CACHE.some(v => v === local) || (base === referrer && base.endsWith(CACHED_FILES[0]));
 	if (isNavigate || isCachable) {
 		event.respondWith(async function () {
-			try {
-				// Use the preloaded response, if it's there
-				let request = event.request.clone();
-				let response = await event.preloadResponse;
-				if (!response) {
-					// Or, go over network.
-					response = await fetch(event.request);
-				}
-				if (isCachable) {
-					// Update the cache
-					const cache = await caches.open(CACHE_NAME);
-					cache.put(request, response.clone());
-				}
-				return response;
-			} catch (error) {
-				const cache = await caches.open(CACHE_NAME);
-				if (event.request.mode === "navigate") {
-					// Check if we have full cache.
-					const cached = await Promise.all(FULL_CACHE.map(name => cache.match(name)));
-					const missing = cached.some(v => v === undefined);
-					const cachedResponse = missing ? await caches.match(OFFLINE_URL) : await caches.match(CACHED_FILES[0]);
-					return cachedResponse;
+			// Try to use cache first
+			const cache = await caches.open(CACHE_NAME);
+			if (event.request.mode === "navigate") {
+				// Check if we have full cache during HTML page request.
+				const fullCache = await Promise.all(FULL_CACHE.map(name => cache.match(name)));
+				const missing = fullCache.some(v => v === undefined);
+				if (missing) {
+					try {
+						// Try network if some cached file is missing (so we can display offline page in case).
+						return await fetchAndCache(event, cache, isCachable);
+					} catch (e) {
+						// And return the hopefully always cached offline page in case of network failure.
+						console.error("Network error: ", e);
+						return await caches.match(OFFLINE_URL);
+					}
 				}
-				const cachedResponse = await caches.match(event.request);
-				return cachedResponse;
+			}
+			const cached = await cache.match(event.request);
+			if (cached) {
+				return cached;
+			} else {
+				// Try network if don't have it in cache.
+				return await fetchAndCache(event, cache, isCachable);
 			}
 		}());
 	}
 });
+
+self.addEventListener("message", (event) => {
+	// No cross origin
+	if (event.origin != self.origin) {
+		return;
+	}
+	const id = event.source.id || "";
+	const msg = event.data || "";
+	// Ensure it's one of our clients.
+	self.clients.get(id).then(function (client) {
+		if (!client) {
+			return; // Not a valid client.
+		}
+		if (msg === "claim") {
+			self.skipWaiting().then(() => self.clients.claim());
+		} else if (msg === "clear") {
+			caches.delete(CACHE_NAME);
+		} else if (msg === "update") {
+			self.skipWaiting().then(() => self.clients.claim()).then(() => self.clients.matchAll()).then(all => all.forEach(c => c.navigate(c.url)));
+		} else {
+			onClientMessage(event);
+		}
+	});
+});
diff --git a/platform/javascript/api/api.cpp b/platform/javascript/api/api.cpp
index 0c4accccc3..4190b24b8e 100644
--- a/platform/javascript/api/api.cpp
+++ b/platform/javascript/api/api.cpp
@@ -71,6 +71,9 @@ void JavaScript::_bind_methods() {
 		ClassDB::bind_vararg_method(METHOD_FLAGS_DEFAULT, "create_object", &JavaScript::_create_object_bind, mi);
 	}
 	ClassDB::bind_method(D_METHOD("download_buffer", "buffer", "name", "mime"), &JavaScript::download_buffer, DEFVAL("application/octet-stream"));
+	ClassDB::bind_method(D_METHOD("pwa_needs_update"), &JavaScript::pwa_needs_update);
+	ClassDB::bind_method(D_METHOD("pwa_update"), &JavaScript::pwa_update);
+	ADD_SIGNAL(MethodInfo("pwa_update_available"));
 }
 
 #if !defined(JAVASCRIPT_ENABLED) || !defined(JAVASCRIPT_EVAL_ENABLED)
@@ -102,6 +105,12 @@ Variant JavaScript::_create_object_bind(const Variant **p_args, int p_argcount,
 }
 #endif
 #if !defined(JAVASCRIPT_ENABLED)
+bool JavaScript::pwa_needs_update() const {
+	return false;
+}
+Error JavaScript::pwa_update() {
+	return ERR_UNAVAILABLE;
+}
 void JavaScript::download_buffer(Vector<uint8_t> p_arr, const String &p_name, const String &p_mime) {
 }
 #endif
diff --git a/platform/javascript/api/javascript_singleton.h b/platform/javascript/api/javascript_singleton.h
index 63f1aec624..e93b0a18a1 100644
--- a/platform/javascript/api/javascript_singleton.h
+++ b/platform/javascript/api/javascript_singleton.h
@@ -59,6 +59,8 @@ public:
 	Ref<JavaScriptObject> create_callback(const Callable &p_callable);
 	Variant _create_object_bind(const Variant **p_args, int p_argcount, Callable::CallError &r_error);
 	void download_buffer(Vector<uint8_t> p_arr, const String &p_name, const String &p_mime = "application/octet-stream");
+	bool pwa_needs_update() const;
+	Error pwa_update();
 
 	static JavaScript *get_singleton();
 	JavaScript();
diff --git a/platform/javascript/export/export_plugin.cpp b/platform/javascript/export/export_plugin.cpp
index 92826630b4..d4c198d631 100644
--- a/platform/javascript/export/export_plugin.cpp
+++ b/platform/javascript/export/export_plugin.cpp
@@ -139,8 +139,7 @@ void EditorExportPlatformJavaScript::_fix_html(Vector<uint8_t> &p_html, const Re
 	}
 	if (p_preset->get("progressive_web_app/enabled")) {
 		head_include += "<link rel='manifest' href='" + p_name + ".manifest.json'>\n";
-		head_include += "<script type='application/javascript'>window.addEventListener('load', () => {if ('serviceWorker' in navigator) {navigator.serviceWorker.register('" +
-				p_name + ".service.worker.js');}});</script>\n";
+		config["serviceWorker"] = p_name + ".service.worker.js";
 	}
 
 	// Replaces HTML string
@@ -188,35 +187,46 @@ Error EditorExportPlatformJavaScript::_add_manifest_icon(const String &p_path, c
 }
 
 Error EditorExportPlatformJavaScript::_build_pwa(const Ref<EditorExportPreset> &p_preset, const String p_path, const Vector<SharedObject> &p_shared_objects) {
+	String proj_name = ProjectSettings::get_singleton()->get_setting("application/config/name");
+	if (proj_name.is_empty()) {
+		proj_name = "Godot Game";
+	}
+
 	// Service worker
 	const String dir = p_path.get_base_dir();
 	const String name = p_path.get_file().get_basename();
 	const ExportMode mode = (ExportMode)(int)p_preset->get("variant/export_type");
 	Map<String, String> replaces;
-	replaces["@GODOT_VERSION@"] = "1";
-	replaces["@GODOT_NAME@"] = name;
+	replaces["@GODOT_VERSION@"] = String::num_int64(OS::get_singleton()->get_unix_time()) + "|" + String::num_int64(OS::get_singleton()->get_ticks_usec());
+	replaces["@GODOT_NAME@"] = proj_name.substr(0, 16);
 	replaces["@GODOT_OFFLINE_PAGE@"] = name + ".offline.html";
-	Array files;
-	replaces["@GODOT_OPT_CACHE@"] = Variant(files).to_json_string();
-	files.push_back(name + ".html");
-	files.push_back(name + ".js");
-	files.push_back(name + ".wasm");
-	files.push_back(name + ".pck");
-	files.push_back(name + ".offline.html");
+
+	// Files cached during worker install.
+	Array cache_files;
+	cache_files.push_back(name + ".html");
+	cache_files.push_back(name + ".js");
+	cache_files.push_back(name + ".offline.html");
 	if (p_preset->get("html/export_icon")) {
-		files.push_back(name + ".icon.png");
-		files.push_back(name + ".apple-touch-icon.png");
+		cache_files.push_back(name + ".icon.png");
+		cache_files.push_back(name + ".apple-touch-icon.png");
 	}
 	if (mode == EXPORT_MODE_THREADS) {
-		files.push_back(name + ".worker.js");
-		files.push_back(name + ".audio.worklet.js");
-	} else if (mode == EXPORT_MODE_GDNATIVE) {
-		files.push_back(name + ".side.wasm");
+		cache_files.push_back(name + ".worker.js");
+		cache_files.push_back(name + ".audio.worklet.js");
+	}
+	replaces["@GODOT_CACHE@"] = Variant(cache_files).to_json_string();
+
+	// Heavy files that are cached on demand.
+	Array opt_cache_files;
+	opt_cache_files.push_back(name + ".wasm");
+	opt_cache_files.push_back(name + ".pck");
+	if (mode == EXPORT_MODE_GDNATIVE) {
+		opt_cache_files.push_back(name + ".side.wasm");
 		for (int i = 0; i < p_shared_objects.size(); i++) {
-			files.push_back(p_shared_objects[i].path.get_file());
+			opt_cache_files.push_back(p_shared_objects[i].path.get_file());
 		}
 	}
-	replaces["@GODOT_CACHE@"] = Variant(files).to_json_string();
+	replaces["@GODOT_OPT_CACHE@"] = Variant(opt_cache_files).to_json_string();
 
 	const String sw_path = dir.plus_file(name + ".service.worker.js");
 	Vector<uint8_t> sw;
@@ -256,10 +266,6 @@ Error EditorExportPlatformJavaScript::_build_pwa(const Ref<EditorExportPreset> &
 	const int orientation = CLAMP(int(p_preset->get("progressive_web_app/orientation")), 0, 3);
 
 	Dictionary manifest;
-	String proj_name = ProjectSettings::get_singleton()->get_setting("application/config/name");
-	if (proj_name.is_empty()) {
-		proj_name = "Godot Game";
-	}
 	manifest["name"] = proj_name;
 	manifest["start_url"] = "./" + name + ".html";
 	manifest["display"] = String::utf8(modes[display]);
diff --git a/platform/javascript/godot_js.h b/platform/javascript/godot_js.h
index 15de8b5dc7..2cb5c3025c 100644
--- a/platform/javascript/godot_js.h
+++ b/platform/javascript/godot_js.h
@@ -49,6 +49,8 @@ extern void godot_js_os_fs_sync(void (*p_callback)());
 extern int godot_js_os_execute(const char *p_json);
 extern void godot_js_os_shell_open(const char *p_uri);
 extern int godot_js_os_hw_concurrency_get();
+extern int godot_js_pwa_cb(void (*p_callback)());
+extern int godot_js_pwa_update();
 
 // Input
 extern void godot_js_input_mouse_button_cb(int (*p_callback)(int p_pressed, int p_button, double p_x, double p_y, int p_modifiers));
diff --git a/platform/javascript/javascript_singleton.cpp b/platform/javascript/javascript_singleton.cpp
index b10e8007c0..77858bff01 100644
--- a/platform/javascript/javascript_singleton.cpp
+++ b/platform/javascript/javascript_singleton.cpp
@@ -30,6 +30,7 @@
 
 #include "api/javascript_singleton.h"
 #include "emscripten.h"
+#include "os_javascript.h"
 
 extern "C" {
 extern void godot_js_os_download_buffer(const uint8_t *p_buf, int p_buf_size, const char *p_name, const char *p_mime);
@@ -355,3 +356,10 @@ Variant JavaScript::eval(const String &p_code, bool p_use_global_exec_context) {
 void JavaScript::download_buffer(Vector<uint8_t> p_arr, const String &p_name, const String &p_mime) {
 	godot_js_os_download_buffer(p_arr.ptr(), p_arr.size(), p_name.utf8().get_data(), p_mime.utf8().get_data());
 }
+
+bool JavaScript::pwa_needs_update() const {
+	return OS_JavaScript::get_singleton()->pwa_needs_update();
+}
+Error JavaScript::pwa_update() {
+	return OS_JavaScript::get_singleton()->pwa_update();
+}
diff --git a/platform/javascript/js/engine/config.js b/platform/javascript/js/engine/config.js
index a6f9c4614c..2e5e1ed0d1 100644
--- a/platform/javascript/js/engine/config.js
+++ b/platform/javascript/js/engine/config.js
@@ -107,6 +107,13 @@ const InternalConfig = function (initConfig) { // eslint-disable-line no-unused-
 		 */
 		experimentalVK: false,
 		/**
+		 * The progressive web app service worker to install.
+		 * @memberof EngineConfig
+		 * @default
+		 * @type {string}
+		 */
+		serviceWorker: '',
+		/**
 		 * @ignore
 		 * @type {Array.<string>}
 		 */
@@ -249,6 +256,7 @@ const InternalConfig = function (initConfig) { // eslint-disable-line no-unused-
 		this.persistentDrops = parse('persistentDrops', this.persistentDrops);
 		this.experimentalVK = parse('experimentalVK', this.experimentalVK);
 		this.focusCanvas = parse('focusCanvas', this.focusCanvas);
+		this.serviceWorker = parse('serviceWorker', this.serviceWorker);
 		this.gdnativeLibs = parse('gdnativeLibs', this.gdnativeLibs);
 		this.fileSizes = parse('fileSizes', this.fileSizes);
 		this.args = parse('args', this.args);
diff --git a/platform/javascript/js/engine/engine.js b/platform/javascript/js/engine/engine.js
index 17a8df9e29..d2ba595083 100644
--- a/platform/javascript/js/engine/engine.js
+++ b/platform/javascript/js/engine/engine.js
@@ -189,6 +189,9 @@ const Engine = (function () {
 							preloader.preloadedFiles.length = 0; // Clear memory
 							me.rtenv['callMain'](me.config.args);
 							initPromise = null;
+							if (me.config.serviceWorker && 'serviceWorker' in navigator) {
+								navigator.serviceWorker.register(me.config.serviceWorker);
+							}
 							resolve();
 						});
 					});
diff --git a/platform/javascript/js/libs/library_godot_os.js b/platform/javascript/js/libs/library_godot_os.js
index 662d215443..12d06a8d51 100644
--- a/platform/javascript/js/libs/library_godot_os.js
+++ b/platform/javascript/js/libs/library_godot_os.js
@@ -368,3 +368,58 @@ const GodotEventListeners = {
 	},
 };
 mergeInto(LibraryManager.library, GodotEventListeners);
+
+const GodotPWA = {
+
+	$GodotPWA__deps: ['$GodotRuntime', '$GodotEventListeners'],
+	$GodotPWA: {
+		hasUpdate: false,
+
+		updateState: function (cb, reg) {
+			if (!reg) {
+				return;
+			}
+			if (!reg.active) {
+				return;
+			}
+			if (reg.waiting) {
+				GodotPWA.hasUpdate = true;
+				cb();
+			}
+			GodotEventListeners.add(reg, 'updatefound', function () {
+				const installing = reg.installing;
+				GodotEventListeners.add(installing, 'statechange', function () {
+					if (installing.state === 'installed') {
+						GodotPWA.hasUpdate = true;
+						cb();
+					}
+				});
+			});
+		},
+	},
+
+	godot_js_pwa_cb__sig: 'vi',
+	godot_js_pwa_cb: function (p_update_cb) {
+		if ('serviceWorker' in navigator) {
+			const cb = GodotRuntime.get_func(p_update_cb);
+			navigator.serviceWorker.getRegistration().then(GodotPWA.updateState.bind(null, cb));
+		}
+	},
+
+	godot_js_pwa_update__sig: 'i',
+	godot_js_pwa_update: function () {
+		if ('serviceWorker' in navigator && GodotPWA.hasUpdate) {
+			navigator.serviceWorker.getRegistration().then(function (reg) {
+				if (!reg || !reg.waiting) {
+					return;
+				}
+				reg.waiting.postMessage('update');
+			});
+			return 0;
+		}
+		return 1;
+	},
+};
+
+autoAddDeps(GodotPWA, '$GodotPWA');
+mergeInto(LibraryManager.library, GodotPWA);
diff --git a/platform/javascript/os_javascript.cpp b/platform/javascript/os_javascript.cpp
index 39eea13ca1..de5ca44f9d 100644
--- a/platform/javascript/os_javascript.cpp
+++ b/platform/javascript/os_javascript.cpp
@@ -45,6 +45,7 @@
 #include <emscripten.h>
 #include <stdlib.h>
 
+#include "api/javascript_singleton.h"
 #include "godot_js.h"
 
 void OS_JavaScript::alert(const String &p_alert, const String &p_title) {
@@ -203,6 +204,19 @@ void OS_JavaScript::file_access_close_callback(const String &p_file, int p_flags
 	}
 }
 
+void OS_JavaScript::update_pwa_state_callback() {
+	if (OS_JavaScript::get_singleton()) {
+		OS_JavaScript::get_singleton()->pwa_is_waiting = true;
+	}
+	if (JavaScript::get_singleton()) {
+		JavaScript::get_singleton()->emit_signal("pwa_update_available");
+	}
+}
+
+Error OS_JavaScript::pwa_update() {
+	return godot_js_pwa_update() ? FAILED : OK;
+}
+
 bool OS_JavaScript::is_userfs_persistent() const {
 	return idb_available;
 }
@@ -226,6 +240,8 @@ OS_JavaScript::OS_JavaScript() {
 	godot_js_config_locale_get(locale_ptr, 16);
 	setenv("LANG", locale_ptr, true);
 
+	godot_js_pwa_cb(&OS_JavaScript::update_pwa_state_callback);
+
 	if (AudioDriverJavaScript::is_available()) {
 #ifdef NO_THREADS
 		audio_drivers.push_back(memnew(AudioDriverScriptProcessor));
diff --git a/platform/javascript/os_javascript.h b/platform/javascript/os_javascript.h
index 3404fe9dcf..9e272f9aa1 100644
--- a/platform/javascript/os_javascript.h
+++ b/platform/javascript/os_javascript.h
@@ -45,11 +45,13 @@ class OS_JavaScript : public OS_Unix {
 	bool idb_is_syncing = false;
 	bool idb_available = false;
 	bool idb_needs_sync = false;
+	bool pwa_is_waiting = false;
 
 	static void main_loop_callback();
 
 	static void file_access_close_callback(const String &p_file, int p_flags);
 	static void fs_sync_callback();
+	static void update_pwa_state_callback();
 
 protected:
 	void initialize() override;
@@ -65,6 +67,9 @@ public:
 	// Override return type to make writing static callbacks less tedious.
 	static OS_JavaScript *get_singleton();
 
+	bool pwa_needs_update() const { return pwa_is_waiting; }
+	Error pwa_update();
+
 	void initialize_joypads() override;
 
 	MainLoop *get_main_loop() const override;