Simple question.
Do browsers cache PHP generated CSS and script files automatically, just like CSS/JS files?
1
-
1Use firebug or the webkit debugger and it will tell you whether the browser is using a cached version or not.Mike B– Mike B2012-08-28 17:21:54 +00:00Commented Aug 28, 2012 at 17:21
Add a comment
|
3 Answers
Sure, barring explicit acts to prevent caching. The browser has no way of knowing if the file was a static or dynamically generated resource.
4 Comments
Tchoupi
It is not always true, especially when using sessions because PHP will send a
Cache-Control:no-store, no-cache, must-revalidate, post-check=0, pre-check=0.
Eric J.
@MathieuImbert: "barring explicit acts to prevent caching". Sending no-cache headers is one means of preventing caching.
Tchoupi
@EricJ. Yes sorry I missed your first sentence.
If the URL remains the same, and there aren't hints in the HTTP responses to tell the browser otherwise, they can be cached.
If the URL includes dynamic information, the browser probably won't be able to take advantage of caching.
Changing the URL by adding a timestamp as a dummy parameter (e.g. http://host/myfile.php?t=17279273) is one of the ways you can prevent caching since the browser sees the slight change as a new resource.
2 Comments
Ed Bayiates
Nice technique on the timestamp!
fpierrat
even better: add the timestamp of the last file modification, so the resource remains cached as long as no change occurs (ex. in php:
$url="http://host/myfile.php?t=".filemtime("myfile.php");Jonathon's answer suggesting the addition of a timestamp to prevent caching is a good one.
A useful tip along these lines is to append the creation/last modified date of a file. Doing this means that while unchanged the browser will cache the file, but when you update the file those changes are forced to your users.
It's not always the best option, but worth noting.
