Improving the AppCache

Last week, Mark Christian & Dustin Diaz published AppCache Facts, a concise and pragmatic documentation about how to write a cache manifest to take your Web applications offline.

AppCache has the potential to benefit many websites, not only in offline scenarios but also on the performance ground. And yet, developers have struggled to use it in their projects because of the initial implementation quirks, the lack of documentation and tooling.

Now that the implementation and documentation parts are good enough, it’s time to get rid of the next papercuts. I gathered an initial list of those little things that could be fixed or improved to make the AppCache useful and convenient:

  • it should be possible to exclude the html file associated with the manifest from the cache,
  • it should be possible to cache resources from other origins on https too,
  • Firefox should stop asking for user permission and let developers see what’s in the AppCache.

What would you add to this list?
Leave a comment, and I’ll make sure the feedback is heard by Mozilla and Google engineers.

One thought on “Improving the AppCache

  1. Jaydson Gomes

    Hi Louis,
    I started to read about AppCache a few weeks ago.
    Well, this feature of HTML5 is really exciting, and i want to push this forward.
    I think that the best way to spread this, is to implement and talk about.
    I started making a blog post, where i tried to explain what is AppCache:
    http://jaydson.org/en/html5-application-cache

    Your list to improve AppCache is exactaly the same that i think, but for me, the first item is the main topic.
    In my tests i saw that in Firefox and Opera it works fine, if the header Cache-Control:no-store is present, the current page is never cached.
    In Chrome, there’s nothing to do. It simply igonores no-store directive, and the current page is always cached.

    I think that the behavior of entire cache be disregarded if some resource can’t be retrieved is kind odd. Don’t you?

    I can’t find in the especification if is possible to mention all resources from a especific type in manifest file, like this:
    *.jpg
    *js
    or:
    /resources/_js/*

    You know if it is possible?

    Thanks!

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