HTML5 application cache fallback not work in Firefox

Question

I am using Firefox latest (11), and I've set IIS to serve *.appcache as text/cache-manifest, and I've double checked Firefox DID cache my files by looking into both "about:cache" "C:\Users\\AppData\Local\Mozilla\Firefox\Profiles\.\OfflineCache" (according to MDN), below is my demo.appcache file:

CACHE MANIFEST
../../js/jquery-1.7.1.js
offline.html

NETWORK:
# Chrome respects *
*
# Firefox respects following, refer: http://appcachefacts.info/
http://*
https://*

FALLBACK:
/ offline.html

CACHE:
foo.js

My steps are described below:

Clear all cache by Options -> Advanced -> "Offline Web Content and User Data" -> "Clear now".
Access my html page with <html manifest="demo.appcache">
I double Firefox did cache my items specified in demo.appcache above.
I switch my Firefox to "Work Offline" by Menu -> Web Developer -> Work Offline.
I access "Online.html" and I am expecting Firefox will render offline.html to me, however, it said "I cannot access the page because I am offline".

Chrome does everything correctly whereas it cannot be switched to "Offline mode", refer: Broken Offline Support Opera can work offline, but it even does cache correctly, it didn't cache offline.html I specified in "Cache" module which obviously violates the standard.

I am struggling with this issue (step 5) for more than 3 days, any help would be highly appreciated!

Nathan Nathan · Accepted Answer · 2012-04-25T14:27:45

I too have been working on this for the past couple days. Reading through your post I was about to post a reply when something hit me.

In Chrome I've been testing this using a Proxy switcher to toggle between my connection and bad proxy information to simulate loss of connection. Like you in Firefox I was using "Work Offline". In my case I was seeing a locally cached version of my "Online" page rather than the Offline fallback I expected.

In Firefox I went to Tools -> Options -> Network -> Settings and changed the Proxy information to see what would happen. It Worked!

So "Work Offline" either is not triggering the Fallback or possibly the local storage at all.

-Nathan

HTML5 application cache fallback not work in Firefox

1 Answers