Initial service worker.

This basic service worker behaves identically to the existing appcache -
some static scripts and CSS are cached, any HTML offline instead returns
a static HTML page that knows how to show data on stored problems out of
localStorage (stored there when /my/planned was visited online). Inspect
form submissions will be captured and can be synced back when online.

Once feature parity is established, we will then remove appcache, switch
from using localStorage to the cache API, and hopefully move all offline
support into the service worker.

1 files changed, 4 insertions, 3 deletions

diff --git a/web/cobrands/fixmystreet/offline.js b/web/cobrands/fixmystreet/offline.js
index 4d7c471aa..648375afd 100644
--- a/web/cobrands/fixmystreet/offline.js
+++ b/web/cobrands/fixmystreet/offline.js
@@ -411,9 +411,10 @@ if ($('#offline_list').length) {
     }
     fixmystreet.offlineBanner.make(true);
 } else {
-    // Put the appcache manifest in a page in an iframe so that HTML pages
-    // aren't cached (thanks to Jake Archibald for documenting this!)
-    if (window.applicationCache && window.localStorage) {
+    // If we're using appcache, not a service worker, put the appcache manifest
+    // in a page in an iframe so that HTML pages aren't cached
+    // (thanks to Jake Archibald for documenting this!)
+    if (!('serviceWorker' in navigator) && window.applicationCache && window.localStorage) {
         $(document.body).prepend('<iframe src="/offline/appcache" style="position:absolute;top:-999em;visibility:hidden"></iframe>');
     }