[whatwg] Improvement of the Application Cache

Edward Gerhold edward.gerhold at googlemail.com
Wed Mar 2 07:40:04 PST 2011


Hello,

i would like to suggest an improvement for the Offline Web applications.

Problem:
I´ve found out, that i can not Cache my Joomla! Content Management System.
Of course i´ve read and heard about, that the application cache is for
static pages.
But with a little change to the spec and the implementations, it would be
possible to cache
more than static pages.

I would like to cache my Joomla! system. To put the scripts, css and images
into the cache.
I would like to add the appcache manifest to the index.php file of the
Joomla Template.
What happens is, that the index.php is cached once and not updated again. I
can not view
new articles. The problem is, that i can neither update the Master File, nor
whitelist it.

And this is, what my request or suggestion is about. I would like to
whitelist the Master
file, where the appcache manifest is installed in. Or i would like to update
this file, or any
file else, i would like to update, on demand.

If there is any possibility, to do that already, please tell me. But i think
that is not the case.

Caching the CMS by making it possible to update or to whitelist certain
files, the always
dynamic frontpage or /index.php, would be the hammer to nail the board on
the storage.

Rules:
The things, which should be considered are: *To allow to fetch the Master
file, e.g. index.php*
*in Joomla! over the NETWORK,* while any other file in the manifest get´s
fetched or cached like
before. Which is the most important for me, to get Joomla! into the cache.

Javascript:
For the script i would like to add *applicationCache.updateMaster()*, which
forces the browser
to fetch the file again. I think, this is impossible today, to update
exactly this file. For the function,
i could add a button to my page, to let the user choose  to update the file.
The second function would be *applicationCache.updateFile(url)*, which could
be triggered by
a button and script, too. I could let the user update certain articles.
With that i would like to suggest* applicationCache.addToCache(url)* to add
files manually or
programmatic, which can not be determined by the manifest. Urls like new
articles (*), i would
like to read offline. I would like to add them to the cache, if the link
appears, maybe on the
frontpage. I would have to add the manifest to the CMS anyways, so i could
add a few
more functions to the page, of course. *
applicationCache.removeFromCache(url)* should
be obvious and helpful with the other functions.
Good would be, to be able to iterate through the list of cached objects and
even the manifest,
with the update, add, remove functions, it would be very useful to work with
the filenames and
parameters.

[(*) I could let the user decide wether he wants to download my mp3 files to
the appcache or not,
and fulfill the wish with the javascript functions. Maybe he´s got no bytes
left or wants only the
lyrics.]

Conclusion:
The application cache is very powerful. But it is very disappointing, that
it is only useful for static
pages. With a little improvement to the Offline Web applications chapter,
and of course to the browsers,
it would be possible to cache any Content Manager or dynamic page. And that
would let the appcache
become one of the most powerful things in the world.

I could read my Joomla! offline, could update the cached files, if i want
to, on a click or if the cache expires.
I could let the half of the CMS load from the cache. But for that, the
index.php, where the manifest is, has to
be updateable. Correct me, if i am wrong. But this is not possible today,
the master file can not be influenced.
And there is no expiration or a possibility to update or manipulate the
cache and even no way to find out which
files are cached, what would let me/us have control over the Offline Web
application.

Question:
Could this become changed in the appcache section? You would make the
appcache so powerful, that any
kind of software could be used offline. I would like to know, how far this
could become true or how much
that is of interest for you. I have not followed this mailing list until
half an hour ago. So i do not know. I learned
what is missing and working by practice and testing the appcache with my cms
and my static hip-hop pages.

Oh, i forgot one thing: Wildcards in the manifest. And I think, directories
belong into the CACHE section,  i got
an error on any directory there, i had to state the whole filename. You
should abbreviate that. But that is not
so important against that what i wrote down in this message above. Anyways,
this completes my wishlist.

Correct me, if i am wrong. But please take this message serious. I hope
other people have submitted this already,
that you could compare or get that underlined, before that spec goes into
last call and becomes standard. The
appcache could become very very and extremly powerful with a little addition
to handle all these dynamic systems, too.

Edward Gerhold


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