CODEWITHSUNDEEP
javascriptcachingrefresh
RANGER
RANGER

Reputation: 1691

Refresh page using cache

I am trying to refresh a page, but WANT to use the cache and can't figure out how to do this. There are two situations:

I've tried: top.location.reload(false); and top.location.reload(true); (I'm sending this from in an iFrame) and neither used the cache. I'm avoiding using location so it doesn't end up in the browser history twice.

Question: How do I reload the page using the cached images? Is there a different javascript function or is this a mod_expires issue?

Thanks for any help in advance!

EDIT: (info from chrome: developer tools)

EDIT 2: (Headers from an image, safari: developer tools)

Javascript: top.location.reload(false); (No Cache!)

Status Code:304 Not Modified

Request Headers
Cache-Control:max-age=0
If-Modified-Since:Tue, 28 Jun 2011 07:13:17 GMT
If-None-Match:"104684ae-a7d-66e41d40"
Referer:http://getdirectus.com/dev/media.php
User-Agent:Mozilla/5.0 (Macintosh; U; Intel Mac OS X 10_6_7; en-us) AppleWebKit/533.21.1 (KHTML, like Gecko) Version/5.0.5 Safari/533.21.1

Response Headers
Cache-Control:max-age=157680000
Connection:Keep-Alive
Date:Tue, 28 Jun 2011 16:56:50 GMT
Etag:"104684ae-a7d-66e41d40"
Expires:Sun, 26 Jun 2016 16:56:50 GMT
Keep-Alive:timeout=5, max=94
Server:Apache/2.0.54

Navigating to page: (Uses cache)

Status Code:200 OK

Response Headers**
Accept-Ranges:bytes
Cache-Control:max-age=157680000
Connection:Keep-Alive
Content-Length:2685
Content-Type:image/jpeg
Date:Tue, 28 Jun 2011 16:54:20 GMT
Etag:"104684ae-a7d-66e41d40"
Expires:Sun, 26 Jun 2016 16:54:20 GMT
Keep-Alive:timeout=5, max=99
Last-Modified:Tue, 28 Jun 2011 07:13:17 GMT
Server:Apache/2.0.54

Upvotes: 2

Views: 7060

Answers (6)

Scott Cramer
Scott Cramer

Reputation: 304

window.location.href = window.location.href;

If the location contains a #, be sure to remove it before setting href.

Upvotes: 1

Spencer
Spencer

Reputation: 979

Your second request was initiated by manually refreshing the page. When you do this, the browser sends up an additional cache-control:max-age=0 header with the request. This is where the 304 (Not Modified) is coming from.

If you navigate within the site (using links), the browser will continue to use its cache.

Upvotes: 0

SpliFF
SpliFF

Reputation: 39014

The documentation for window.location.reload( false ); says it will load from cache. If that isn't happening then you may be seeing a browser bug. See if you can replicate the problem in another browser.

EDIT (for your edit): You are seeing that behaviour because you don't have an Expires header set in the future. You will need to add an Expires header in Apache.

Upvotes: 5

Martin Jespersen
Martin Jespersen

Reputation: 26183

There are two separate things to consider here:

1: the request... browser -> server

2: the response... server -> browser

When you refresh a page you cannot get around the browser doing a requests for page assets to the server.

What you can do is make sure the server sends a minimal response.

The best way to achieve this, is to use etags in your response headers. That way the browser will send a if-none-match request to the server, and get a 304 Nothing changed response back assuming nothing has been modifed.

Upvotes: 0

Ravan Scafi
Ravan Scafi

Reputation: 6392

Using this site, I only got green image with location.refresh(true);. With location.refresh(); or location.refresh(false); I got the red image. Working ok, I guess.

Upvotes: 0

Florian
Florian

Reputation: 3191

If you want to enable caching in the client, mind sending Expire headers, e.g. with mod_expires

Upvotes: 0

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