Application cache: strange behaviour on iPad

I'm making a website where a user can say which items he wants to cache. Based on this, a manifest file is generated. By doing this the user can still browse in the website when he is offline. This is all working fine in google chrome. But on iPad it's not working as it should. Sometimes things get cached sometimes not, not even the pages i visited.

We have been testing with 2 iPads all morning, but we haven't been able to get the same result on both iPads. Even if we do exactly the same, we sometimes get different results.

So what we do:

• turn WiFi on
• browse to the website
• make some settings so some pages/images/... are added to the manifest file
• turn WiFi off
• go back to safari refresh/browse to pages that should be cached.

Sometimes on one iPad (this is an iPad 1) it works exactly as it should, but sometimes it doesn't work at all. On the other iPad (this is an iPad 2) it never works completely as it should. Just some random results.

It also looks like the results are different when we comp开发者_开发百科letely shutdown safari, and then clear the cache and then do the whole process of downloading and caching stuff...

Somebody can help me with this problem? It's a real pain in the ass at the moment... :(

1. Open web server (IIS)
2. Select website
3. Open MIME type
4. Add or edit to text/cache-manifest
5. Reset iis at command prompt iisreset

It works for me.

I've encountered some problems as well with ipad caching.

1. MIME type of the manifest file is not set right due to windows hosting. The standard MIME type on a windows server is "application/x-ms-manifest". This was created when the ClickOnce applications came to life. The MIME type that is necessary to work on safari is: "text/cache-manifest"

2. Cache size is too small on ipad (you should get a warning to enlarge it)

3. the Ipad needs time! I've noticed that the cache is not filled when you see all assets or when the website is "loaded". Give it twice the normal time to load before you place the website to your homescreen.

4. Cache of the cache :) The iPad only reloads the files when the modified date on the server is changed. So when you really want to test, clear all cache on the iPad, remove the link on the homescreen and upload all your files again.

Conclusion: Time consuming!

Hint: Turn on the debug console in safari on your desktop or iPad. It gives a fair idea if you did something wrong or if it is a cache problem on the iPad.

It looks like the problem didn't have anything to do with the application cache. It was somehow a problem with the cookies/the way i was dynamically building the manifest file.

I'd like to slightly echo Pieter-Paulus Vertongen, I had a similar experience with Windows hosting.

According to the debugging console in Safari, the mime type for the manifest file was being misread and nothing was being downloaded as a result.

I copied all of my files, including the .htaccess file, over to a linux server without changing any content within the files...and then the caching worked beautifully.

So yes, it's possible this may be an issue of where the files are hosted. Use the debugging console and Jonathan Stark's code to find out:

http://jonathanstark.com/blog/debugging-html-5-offline-application-cache?filename=2009/09/27/debugging-html-5-offline-application-cache/