About HTML5 offline storage

Question

I have a few questions regarding HTML5 offline storage, which I could not figure out.

1. Where exactly these files are stored in the Windows? I could not find here:

   C:\Documents and Settings[User Name]\Application Data\Mozilla\Firefox\Profiles\

2. Is there any expiration time, after that browser deletes these files automatically? Or do the files remain forever?

3. What if I change the contents of the page, is there anyway to refresh the refresh the data which is stored offline?

Thanks.

Answer 1

1. I found them in %AppData%/Profiles/<currentprofilename>.default/OfflineCache. I'm using Windows 7.

2. This depends on the expires headers your web server sends for the files in question. It is recommended you set the expires header to one week, but it is up to you, you can make it never expire. Note that the manifest file itself should be set to never be cached.

3. In order to refresh the data you must actually change the manifest file. It is recommended that somewhere in the manifest file you put a comment with the version number, then update it every time you change any of your other files.

Edit: I had answered these questions thinking you meant offline application cache, not local storage.

Answer 2

Well, for the sake of accuracy, it should be mentioned that although localStorage was indeed part of the HTML5 specification, it was split into its own after getting slightly over-complicated to be include alongside with the rest of HTML5.

1. It really depends on your browser, but it should be found on your AppData folder, in /profiles//OfflineCache. (for Windoes 7).

2. There is generally NO expiration date for localStorage, it can remain forever unless specifically removed by the website.

3. Javascript changes the localStorage data, (assuming you don't touch the actual file), in which case, the website you are using (or writing) needs to be smart enough to refresh the localStorage along with the page's content.