I can't stop Chrome from loading resources from the cache manifest. I changed my markup so
the page begins with:
<!DOCTYPE html>
<html class="fouc">
<head>
I grabbed this markup after I dumped Chrome's appcache manually and I viewed source.
However, Chrome's console has:
Document was loaded from Application Cache with manifest http://localhost:47932/Manifest/Index localhost/:1
Application Cache Checking event localhost/:1
Application Cache NoUpdate event
How do I turn appcache off once I've turned it on?!
I should mention that I edited my cache manifest. It now reads:
CACHE MANIFEST
#Version 107
NETWORK:
*
CACHE:
I have removed every entry from the Cache section, and Chrome still refers to the cache manifest.
The HTML page specifying the manifest is itself implicitly cached, so the browser won't "see" your update to the HTML unless you update the manifest as well (or delete it). Did you make a change to the application cache manifest after changing the HTML? The byte content of the manifest must change to trigger the browser to check for updated versions of any cached resources.
If all else fails, you can clear Chrome's application cache manually by visiting chrome://appcache-internals/
Remove your manifest file from the server. Or just rename it.
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 need to disable cache for browsers however when I add a manifest file to the server, it displays old html.
Here's my manifest file (cache.manifest):
CACHE MANIFEST
# Cache manifest version 1.0
CACHE
#no cache
NETWORK
*
The cache manifest is for offline applications and controls the creation and use of a local copy of an application. It’s not really a cache, and it is very different normal caching. The HTML document containing the manifest attribute is always included in the application “cache”. This means that in supporting browsers, the HTML file, once loaded, will be stored locally and the local copy will be used in all subsequent accesses to its URL, without ever fetching it again from a server—unless the content of the manifest file changes.
To affect normal caching, use cache control tools provided by the server software or, if you cannot, use meta hacks. See Caching Tutorial for Web Authors and Webmasters.
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/
I have a special kiosk-solution with chrome where I need chrome to upon application start, load the start-url from cache, not try to fetch it online.
The reason is that this is, like I said, a kiosk-mode presentation, is is a screen standing in the public that reboots every night, and if the reboot happens while the ISP has downtime on the internet connection, chrome will only show an error page.
If I can get it to load the cached version of the page though, instead of trying to fetch it online, then the last valid version of the page will show, and through some nifty ajax-workings of mine ;) it will automatically update after a while. If THAT update fails, the currently displayed version of the page will remain until a subsequent update succeeds.
See my problem?
In a browser like firefox I could do it by starting the browser in off-line mode and after page load switch it to online-mode. Only FF doesn't work for me in the particulat project, and Chrome doesn't seem to have an off-line mode?
You could use HTML5 Offline Web Applications to accomplish that. It's probably very easy to set up in your case, just add a file like the following to your app's directory:
CACHE MANIFEST
index.html
help.html
style/default.css
images/logo.png
images/backgound.png
NETWORK:
server.cgi
This manifest should contain all the files you'll need to display some useful information and later grab current content via AJAX. There's also a NETWORK section, where you have to specify things that should not be cached (ie the script that delivers your Updates via AJAX).
You can load the manifest file by adding a manifest attribute to your tag (cache-manifest is the name of the file above):
<html manifest="cache-manifest">
Make sure your server delivers the cache manifest with a MIME-type of
text/cache-manifest MIME
Type or copy-paste the below flag setting into the chrome address bar.
chrome://flags/#enable-offline-mode
scroll down to enable offline stale mode.
Restart your browser.
If an offline version of the page is available in the system cache it will load up when you are not connected.
I have an index.php file in my docroot. It produces output that starts with this:
<!DOCTYPE html>
<html manifest="manifest.appcache">
The manifest.appcache tells browsers to cache it for offline use. Again, the relevant parts:
CACHE MANIFEST
#version 8-25-2011
CACHE:
#internal HTML documents
#this tells the browser to cache the HTML it retrieves from http://example.com/
/
NETWORK:
*
Offline access is working fine with this setup, but updating is not working as I would expect in Firefox.
In Chrome and Safari, when I update the index.php file and then change a comment in the cache.manifest file, the browsers will grab the new index.php output and use that in the cache.
However, in Firefox, it seems to not care that I've updated the manifest.appcache file. I suspect that if I wait long enough, it will update, but I've tried waiting hours.
How can I find and eliminate my caching problem?
What HTTP cache headers are you sending with your index.php file? If you've not set things like the Cache-control: and Expires: headers then Firefox could be refreshing the application cache version of the page from it's regular cache instead of requesting it again from the server.
EDIT BY POSTER OF THE QUESTION:
For anyone that wants to know what exactly it took, here's what I put in my .htaccess file based on this answer and a perusal of http://www.diveintohtml5.info/offline.html:
<Files *.appcache>
ExpiresActive On
ExpiresDefault "access"
</Files>
Hope that helps the next person!
I know I'm really late to the party but I've been seeing this issue in Firefox for years and was hoping that the underlying bug would be fixed.
Unfortunately that hasn't happened but I've finally come up with a workaround. In my case, whilst the new .appcache file is loaded and processed, a page reload does not cause the newly cached versions to be used. The process I'm using goes as follows:
index.html is loaded and specifies the .appcache file in the html tag.
The .appcache file is generated dynamically using a PHP script. The script hashes all included files to create a unique version hash, which is included in the manifest. This means a change in any files listed in the manifest forces a cache reload.
My .htaccess file has the following to prevent the .appcache manifest from being cached:
<Files *.appcache>
ExpiresActive On
ExpiresDefault "access plus 0 seconds"
</Files>
My Javascript code detects the appcache update and reloads the page once the updated files have been fetched:
appCache.addEventListener('updateready', function(e) {
console.log("Appcache update finished, reloading...");
setLoadingBar(100, "Loading...");
appCache.swapCache();
location.reload();
});
Once the page reloads, the old cache is still used in Firefox until the cache is manually cleared by the user. In all other browsers I've tested, the newly cached files take immediate affect.
The fix turned out to be painfully simple!
All that was needed was to change the location.reload() line to include the true parameter:
location.reload(true)
This seems to indicate that Firefox serves the files from it's normal cache rather than using the appcache stored files, even when the appcache'd files are newer. I'm guessing this is because Firefox puts the normal caching mechanism in front of appcache like so:
Request -> Normal cache -> Appcache -> Network request
But that's just a guess.