Is there a way to "cache everything" on a website so that you dont have to add every resource by uri to the manifest?
Something like:
CACHE MANIFEST
*.png
instead of
CACHE MANIFEST
my_image_1.png
my_image_2.png
my_image_3.png
my_image_4.png
my_image_5.png
my_image_6.png
my_image_7.png
...
No: the CACHE section doesn't allow wildcards. But if it's simpler for you insert the manifest entry () in every page you want to cache. Every page with that entry gets cached even without being included in the manifest (master entries).
Related
I changed my cache.manifest file to the following:
CACHE MANIFEST
NETWORK:
*
CACHE:
FALLBACK:
This triggered an update to my site.
I tried adding a "#" to the manifest file and then removed the manifest="cache.manifest"from my page.
This triggered the cache to be updated again, even though the reference to the manifest was gone. The console indicated it was still being loaded from cache.
I even tried renaming my cache.manifest file and it still was being loaded from cache.
How in the world can I safely stop using cache manifest? I have a completely new version of my site I want to roll out, but if cache manifest is still trying to cache the new site, that will be a disaster for all my visitors who do not know they need to clear their browser cache.
I believe I found the trick.
It seems I need to keep the old cache.manifest but change (not remove) the reference to a non-existent manifest file.
Presumably, I'll need to keep the broken reference there for several years in case I have visitors who only visit periodically.
I am testing HTML5's offline capabilities, and the cache seems to be a bit overactive. My cache.appcache file is as follows:
CACHE MANIFEST
CACHE:
#v1.4
js/js.js
NETWORK:
network2.html
FALLBACK:
/ offline.html
Basically I want to only display network2.html when the web is available - otherwise it should fall back to offline.html.
However, if I have accessed network2.html with the web connection live it keeps displaying it when there is no connection - surely it should fall back to offline.html? I thought only pages referenced in the CACHE section should be cached in the first place anyway?
I have tried in multiple browsers, clearing the browser data, refreshing multiple times etc.
Sorted it - it turns out that any file whose html tag references the manifest will be cached itself, whether or not that file is mentioned in the CACHE section. This even overrides if it is referenced in the NETWORK section.
Thanks to robertc on this answer which gave me the tip.
In short, you only need to have one reference to the manifest, usually in your 'default' view, not all files that may be referenced by the manifest itself. Not very clear in the HTML5 docs.
When setting the prefer-online setting I expect the browser to request the page at every refresh of the browser, but it is not the case.
Here is my manifest :
CACHE MANIFEST
SETTINGS:
prefer-online
NETWORK:
*
Yet when I refresh the browser it only requests the manifest to the server. It only requests the page when I update the manifest ...
And there is no headers (expires or max-age) set on the page.
(tested on chrome & firefox)
NB: When updating the manifest, the browser re downloads the assets, but still displays the old version ... It is only on the next load that the browser uses the new assets. Why ?
I don't see what the AppCache manifest is for, since you want to bypass the cache and just use the network. Keep in mind that the regular caching might still apply, regardless of the AppCache manifest, so check the Expires, Last-Modified and similar headers.
As for your question:
NB: When updating the manifest, the browser re downloads the assets, but still displays the old version ... It is only on the next load that the browser uses the new assets. Why ?
This is because the user agent will immediately use the latest cached version of your assets, then start checking the linked resources listed in the manifest for updates. When the user agent detects that the manifest has changed, and thus it has to check for updates, it will fire a checking event.
When the update checking process has finished (and it might take a long time, if you have lots of resources) it will fire an updateready event. Only the resources fetched after this event will be the fresh new ones (that's why it's usually adviceable to use window.applicationCache.swapCache() to tell the browser to swap the old cache for the new for the next page load, or simply reload the page and be done with it).
You will find more detailed explanations about these topics here: http://www.html5rocks.com/en/tutorials/appcache/beginner/
Every URL can be linked to a single cache manifest. But I want several cache manifests linked to a same URL. Here is the reason:
Some files I want to be cached are rarely updated and large.
So everytime the cache gets updated these large files get re-downloaded even though they may not have been changed.
So I want to split up the cache. One cache for theses rarely updated large files and another cache for the often updated light files.
Do you guys have any idea how to split up an HTML5 cache?
The most efficient way is:
a) Use far-future expiration date (max-age) on all resources mentioned in manifest's CACHE section and add timestamp suffix to each file in the CACHE section, e.g.:
CACHE:
menu_1355817388000.js
toolbar_1355817389100.js
b) When any of the above files change on the server, regen/update manifest to change the timestamp. Only the file with the modified timestamp will get downloaded next time. Mission accomplished.
Note: Reload the page twice in the browser, as on the first refresh browser downloads just the manifest and uses old cached resources to paint the page. This is done to speed up displaying the page (there are tricks to handle this issue of double refresh, but they are outside the scope of your question)
See more info in this long but best article I ever seen on appcache.
Use an iframe
Your page's cache manifest would include the light files and the cache manifest of an iframe loaded by this page would include the large files
On chrome the iframe's application cache will also be used for the page. I didn't tested this method on other browsers yet.
see a live example at http://www.timer-tab.com and if you are using chrome see its split up cache at chrome://appcache-internals/
When the manifest file is changed and the files of the application cache are downloaded again, the normal HTTP caching rules still apply. This means that if you set the correct HTTP caching headers for these large files, you'll get a 304 so these files are not downloaded again. So it's not necessary to split the application cache.
Maybe an answer but I'd more like to shed some light on my findings as a I troubleshoot my own webapp.
I've discovered that I can use 2 iframes (manifest_framework) and (manifest_media) to load the manifests, but i'm still not exactly clear how they are targetted, but I had limited success.
manifest_framework:
CACHE MANIFEST
CACHE:
appdata.ini
dialog.png
jquery.min.js
login.htm
login.js
manifest.appcache.js
NETWORK:
*
FALLBACK:
manifest_media:
CACHE MANIFEST
CACHE:
manifest_fwk.php
od/audio_track_1_1.m4a
od/audio_track_1_2.m4a
od/audio_track_1_3.m4a
od/audio_track_1_4.m4a
od/video_1.mp4
od/video_2.mp4
od/video_3.mp4
NETWORK:
*
FALLBACK:
./ webapp.php
./index.php is the page the 'landing page' which itself isn't cached but falls back to webapp.php when offline.
What I don't understand is how these link to the webapp.php page.
I am finding I can only get access to one or the other manifests cache.
The above works in mobile safari, the media would be cached, and image but not necessarily the JS or images in the framework manifest.
Anyone have more examples where multiple manifests are referenced from the one URL/page?
The W3C working group has abandoned the file system api, so it SHOULD NOT BE USED anymore.
We'll likely see it fall off the next version of Chrome.
http://www.w3.org/TR/file-system-api/
CACHE MANIFEST
# This is a comment.
# Cache manifest version 0.0.1
# If you change the version number in this comment,
# the cache manifest is no longer byte-for-byte
# identical.
demoimages/mypic.jpg
demoimages/yourpic.jpg
demoimages/ourpic.jpg
sr/scroll.js
NETWORK:
# All URLs that start with the following lines
# are whitelisted.
# whitelisted items are needed to help the site function, you could put regularly
# changing items here
http://example.com/examplepath/
http://www.example.org/otherexamplepath/
CACHE:
# Additional items to cache.
demoimages/allpics.jpg
FALLBACK:
demoimages/currentImg.jpg images/stockImage.jpg`
If the Iframe trick does not work, use the HTML5 FileSystem API
See http://updates.html5rocks.com/2012/04/Taking-an-Entire-Page-Offline-using-the-HTML5-FileSystem-API
I have an application which used to use the HTML5 offline cache. Now I've decided to not use it anymore and removed the manifest attribute from the index.html file. However, browsers still regard this site as cached and refuse to update the index.html file.
Even updating the manifest doesn't help. How can I remove the site from the user's offline caches? Am I stuck with a cached web site forever?
You need to make sure the manifest file isn't being cached, which by default it will be.
Adding
ExpiresActive On
ExpiresDefault "access"
To your .htaccess will stop everything being cached, though you really just want the manifest file to be cached in this way like this: (remember to update filename)
<Files cache.manifest>
ExpiresActive On
ExpiresDefault "access"
</Files>
You really need to do that first, but this should alleviate the problem.
I'd recommend reading through Mark Pilgrim's page on this as well.
Try changing contents of your manifest to simply CACHE MANIFEST with no files listed. The clients should retrieve the new manifest next time they hit the site and their cache should be removed.
Note however that they won't be using this new, empty manifest until they refresh the page.
I've found that in some cases on some browsers they don't necessarily grab the new manifest right away. This behavior seems inconsistent though. When this happens I tend to clear their caches / offline storage manually in order to force them to update (though I understand you can't necessarily get users to do this).