HTML5 - cache manifest working great on Chrome but not on Firefox and Opera

Question

I am developing a web app for offline use, thus I need to use the application cache functionality.

Everything works great on Chrome (15.0.874.106) but is doesn\'t wo

Answer 1

In my experience using the HTML5 AppCache, it is great once you get it working, but extremely brittle. If there's the tiniest thing wrong with it the browser ignores the entire file and, annoyingly, rather than use the browser's ordinary cache, re-loads everything from scratch off the server.

Worse, browsers will not re-load the manifest file unless its text content changes. So you might tweak your server headers or something to fix it, but unless the content of cache.manifest.php changes the browser will blindly ignore it and do exactly what it did last time. So it could have been broken, then you fixed it, but browsers are ignoring the changes because the text content of cache.manifest.php hasn't changed. This even seems to be immune to clearing your browser cache, which is part of what makes it so confusing - app cache is really, really serious about caching.

To get around this, text changes in comments count, so have a comment at the top with a version or timestamp or the date (e.g. # Version 1.2) and change that when you want the browser to "notice".

Then, the browser still won't immediately use it! The way the app cache works is the next time you load the page it will do exactly what it did last time yet again, and start checking for an update in the background. So you probably want the console up, wait for something like "updating..." then "complete", then hit Refresh and the browser will finally start using the new version. At last!

All in all it can be a right pain to get working. However, once it's working it's almost bulletproof: you can pretty much rest assured anything listed in the cache manifest is only every downloaded once, ever, for all time, per user, until you change the text content of the file.

Browser standards compliance is pretty good these days, so my best guess is you actually have it working, but you checked Chrome last and it's the only browser which has cached the manifest file correctly. During development you might have had it broken, but Firefox and Opera are clutching their old manifest files to the death. I bet you also tried clearing the browser cache in Firefox and Opera, which probably did nothing - you need to change the text content of the file and double-refresh before either Firefox and Opera will finally give up their broken versions of the manifest file and start using the one which works which you probably uploaded ages ago.

Answer 2

From my experience with getting a site working offline on the iPad:

• The name of the file needs to end with .manifest
• The mime type needs to be text/cache-manifest
• Have a version in the comments of your manifest
• Create some javascript functions using window.applicationCache... to check if the browser sees a change in the manifest and to reload the content, also capture the status events and display them somewhere

See also: http://developer.apple.com/library/safari/#documentation/iPhone/Conceptual/SafariJSDatabaseGuide/OfflineApplicationCache/OfflineApplicationCache.html#//apple_ref/doc/uid/TP40007256-CH7-SW1

Answer 3

Try removing:

header("Cache-Control: max-age=0, no-cache, no-store, must-revalidate");
header("Pragma: no-cache");
header("Expires: Wed, 11 Jan 1984 05:00:00 GMT");

so that you are only sending the Content-type header:

<?php header('Content-type: text/cache-manifest'); ?>

ApplicationCache forces caching (oversimplifying, but not by much). Those first three headers are ways to prevent caching.

Opera appears to prevent caching when those headers are present. Firefox' debugging tools are a bit wonky when it comes to debugging AppCache, but it's probably save to assume this will fix it there as well.

Answer 4

I had the same problem also. Everything worked fine in Chrome and IE, but an "Unable to connect" message in FF.

After hours of despair, i found the solution and it was ridiculous simple: In the developer-toolbar the entire cache was deactivated. :/

Answer 5

I've found something similar, and tracked it down to the Cache-Control: no-store heading on the manifest. Chrome accepts this, but Firefox fails silently with this.

My tests showed that you can keep no-cache headers & expires headers in to ensure frequent refreshes.

Answer 6

I had a similar problem. I am very late in answering but this might be helpful for others. Make sure you dont run into problems described by AshleysBrian in his answer. Adding to that

1. Make sure the manifest file is served as type "text/cache-manifest"
2. Dont try it out in Private Browsing mode in Firefox/IE. It only works in regular browsing mode. But it works in both modes in Chrome

3. While offline, a simple change in the URL could be a problem

   Eg: http://localhost:8080/app doesn't work on Firefox/IE
   but http://localhost:8080/app/ works in Firefox/IE 
   

   Both of them work in Chrome

4. Use these handy resource viewers to get more detailed perspective

   about:cache - Firefox
   chrome://appcache-internals/ - Chrome
   Pls fill in if someone knows what is it for IE