As far as I know a common solution is to add a ?<version>
to the script's src link.
For instance:
<script type="text/javascript" src="myfile.js?1500"></script>
I assume at this point that there isn't a better way than find-replace to increment these "version numbers" in all of the script tags?
You might have a version control system do that for you? Most version control systems have a way to automatically inject the revision number on check-in for instance.
It would look something like this:
<script type="text/javascript" src="myfile.js?$$REVISION$$"></script>
Of course, there are always better solutions like this one.
This solution is written in PHP, but it should be easily adapted to other languages.
The original .htaccess
regex can cause problems with files like json-1.3.js
. The solution is to only rewrite if there are exactly 10 digits at the end. (Because 10 digits covers all timestamps from 9/9/2001 to 11/20/2286.)
First, we use the following rewrite rule in .htaccess:
RewriteEngine on
RewriteRule ^(.*)\.[\d]{10}\.(css|js)$ $1.$2 [L]
Now, we write the following PHP function:
/**
* Given a file, i.e. /css/base.css, replaces it with a string containing the
* file's mtime, i.e. /css/base.1221534296.css.
*
* @param $file The file to be loaded. Must be an absolute path (i.e.
* starting with slash).
*/
function auto_version($file)
{
if(strpos($file, '/') !== 0 || !file_exists($_SERVER['DOCUMENT_ROOT'] . $file))
return $file;
$mtime = filemtime($_SERVER['DOCUMENT_ROOT'] . $file);
return preg_replace('{\\.([^./]+)$}', ".$mtime.\$1", $file);
}
Now, wherever you include your CSS, change it from this:
<link rel="stylesheet" href="/css/base.css" type="text/css" />
To this:
<link rel="stylesheet" href="<?php echo auto_version('/css/base.css'); ?>" type="text/css" />
This way, you never have to modify the link tag again, and the user will always see the latest CSS. The browser will be able to cache the CSS file, but when you make any changes to your CSS the browser will see this as a new URL, so it won't use the cached copy.
This can also work with images, favicons, and JavaScript. Basically anything that is not dynamically generated.
Best Answer
This is how I solved this problem.
Method 1: When the URL changes whenever image changes
diskCacheStrategy() can be used to handle the disk cache and you can skip the memory cache using skipMemoryCache() method.
Method 2: When URL doesn't change, however, image changes
If your URL remains constant then you need to use Signature for image cache.
Glide signature() offers you the capability to mix additional data with the cache key.
MediaStoreSignature
if you are fetching content from media store.MediaStoreSignature
allows you to mix the date modified time, mime type, and orientation of a media store item into the cache key. These three attributes reliably catch edits and updates allowing you to cache media store thumbs.StringSignature
as well for content saved as Files to mix the file date modified time.