diff --git a/.gitignore b/.gitignore
index 789f14aecd..1ecebf0dac 100644
--- a/.gitignore
+++ b/.gitignore
@@ -16,3 +16,4 @@ public/google*.html
report.html
composer.phar
app.js.map
+.idea
\ No newline at end of file
diff --git a/frontend/src/serviceworker.js b/frontend/src/serviceworker.js
new file mode 100644
index 0000000000..1eb9b19f82
--- /dev/null
+++ b/frontend/src/serviceworker.js
@@ -0,0 +1,58 @@
+/*
+ * serviceworker.js
+ * Copyright (c) 2021 james@firefly-iii.org
+ *
+ * This file is part of Firefly III (https://github.com/firefly-iii).
+ *
+ * This program is free software: you can redistribute it and/or modify
+ * it under the terms of the GNU Affero General Public License as
+ * published by the Free Software Foundation, either version 3 of the
+ * License, or (at your option) any later version.
+ *
+ * This program is distributed in the hope that it will be useful,
+ * but WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
+ * GNU Affero General Public License for more details.
+ *
+ * You should have received a copy of the GNU Affero General Public License
+ * along with this program. If not, see .
+ */
+
+let staticCachePrefix = "firefly-III-"
+let staticCacheName = staticCachePrefix + new Date().getTime();
+let cachedFiles = [
+ '/offline',
+ '/v2/plugins/local-fonts/gf-source.css',
+ '/v2/css/app.css',
+];
+
+// Create cache on install
+self.addEventListener("install", event => {
+ this.skipWaiting();
+ event.waitUntil(
+ caches.open(staticCacheName).then(cache => cache.addAll(cachedFiles))
+ )
+});
+
+// Clear cache on activate
+self.addEventListener('activate', event => {
+ event.waitUntil(
+ caches.keys().then(cacheNames => {
+ return Promise.all(
+ cacheNames
+ .filter(cacheName => (cacheName.startsWith(staticCachePrefix)))
+ .filter(cacheName => (cacheName !== staticCacheName))
+ .map(cacheName => caches.delete(cacheName))
+ );
+ })
+ );
+});
+
+// Serve from Cache or return the offline page
+self.addEventListener("fetch", event => {
+ event.respondWith(
+ caches.match(event.request)
+ .then(response => (response || fetch(event.request)))
+ .catch(() => caches.match('offline'))
+ )
+});
diff --git a/public/serviceworker.js b/public/serviceworker.js
new file mode 100644
index 0000000000..1eb9b19f82
--- /dev/null
+++ b/public/serviceworker.js
@@ -0,0 +1,58 @@
+/*
+ * serviceworker.js
+ * Copyright (c) 2021 james@firefly-iii.org
+ *
+ * This file is part of Firefly III (https://github.com/firefly-iii).
+ *
+ * This program is free software: you can redistribute it and/or modify
+ * it under the terms of the GNU Affero General Public License as
+ * published by the Free Software Foundation, either version 3 of the
+ * License, or (at your option) any later version.
+ *
+ * This program is distributed in the hope that it will be useful,
+ * but WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
+ * GNU Affero General Public License for more details.
+ *
+ * You should have received a copy of the GNU Affero General Public License
+ * along with this program. If not, see .
+ */
+
+let staticCachePrefix = "firefly-III-"
+let staticCacheName = staticCachePrefix + new Date().getTime();
+let cachedFiles = [
+ '/offline',
+ '/v2/plugins/local-fonts/gf-source.css',
+ '/v2/css/app.css',
+];
+
+// Create cache on install
+self.addEventListener("install", event => {
+ this.skipWaiting();
+ event.waitUntil(
+ caches.open(staticCacheName).then(cache => cache.addAll(cachedFiles))
+ )
+});
+
+// Clear cache on activate
+self.addEventListener('activate', event => {
+ event.waitUntil(
+ caches.keys().then(cacheNames => {
+ return Promise.all(
+ cacheNames
+ .filter(cacheName => (cacheName.startsWith(staticCachePrefix)))
+ .filter(cacheName => (cacheName !== staticCacheName))
+ .map(cacheName => caches.delete(cacheName))
+ );
+ })
+ );
+});
+
+// Serve from Cache or return the offline page
+self.addEventListener("fetch", event => {
+ event.respondWith(
+ caches.match(event.request)
+ .then(response => (response || fetch(event.request)))
+ .catch(() => caches.match('offline'))
+ )
+});
diff --git a/resources/lang/en_GB/errors.php b/resources/lang/en_GB/errors.php
index 1818adc8c6..b63c231504 100644
--- a/resources/lang/en_GB/errors.php
+++ b/resources/lang/en_GB/errors.php
@@ -47,5 +47,8 @@ return [
'tell_more' => 'Tell us more than "it says Whoops!"',
'include_logs' => 'Include error logs (see above).',
'what_did_you_do' => 'Tell us what you were doing.',
+ 'offline_header' => 'You are probably offline',
+ 'offline_unreachable' => 'Firefly III is unreachable. Your device is currently offline or the server is not working.',
+ 'offline_github' => 'If you are sure both your device and the server are online, please open a ticket on GitHub.',
];
diff --git a/resources/lang/en_US/errors.php b/resources/lang/en_US/errors.php
index 1818adc8c6..b63c231504 100644
--- a/resources/lang/en_US/errors.php
+++ b/resources/lang/en_US/errors.php
@@ -47,5 +47,8 @@ return [
'tell_more' => 'Tell us more than "it says Whoops!"',
'include_logs' => 'Include error logs (see above).',
'what_did_you_do' => 'Tell us what you were doing.',
+ 'offline_header' => 'You are probably offline',
+ 'offline_unreachable' => 'Firefly III is unreachable. Your device is currently offline or the server is not working.',
+ 'offline_github' => 'If you are sure both your device and the server are online, please open a ticket on GitHub.',
];
diff --git a/resources/lang/it_IT/errors.php b/resources/lang/it_IT/errors.php
index bdd4fe0a54..d95331ced9 100644
--- a/resources/lang/it_IT/errors.php
+++ b/resources/lang/it_IT/errors.php
@@ -47,5 +47,8 @@ return [
'tell_more' => 'Dicci di più di "dice Oops!"',
'include_logs' => 'Includi i log degli errori (vedi sopra).',
'what_did_you_do' => 'Dicci cosa stavi facendo.',
+ 'offline_header' => 'Sembreresti essere offline',
+ 'offline_unreachable' => 'Firefly III non è raggiungibile. Il tuo dispositivo sembrerebbe offline, o il server non sta funzionando.',
+ 'offline_github' => 'Se si è certi che sia il server che il dispositivo siano correttamente funzionanti, si può aprire un ticket GitHub.',
];
diff --git a/resources/views/errors/Offline.twig b/resources/views/errors/Offline.twig
new file mode 100644
index 0000000000..b1130978ee
--- /dev/null
+++ b/resources/views/errors/Offline.twig
@@ -0,0 +1,41 @@
+
+
+
+
+
+
+ Firefly III | Offline
+
+
+
+
+
+
+
+
+
+