Disable browser caching

Collapse
This topic is closed.
X
X
Collapse
 
  • Page of 1
  • Time
  • Show
Clear All
new posts
Previous template Next
  • Stefan Mueller
    #1

    Disable browser caching

    Today I'm using
    <html>
    <head>
    <meta http-equiv = "pragma" content = "no-cache">
    </head>


    This prevent the browser to cache the page. So each time I call the
    following PHP script
    <?php
    echo date("d.m.Y") . " / " . date("H:i:s") . "<br>";
    ?>
    the current time will be displayed.

    However, if I call this PHP script over a proxy the time gets not updated.
    I always have to press Shift + Reload.

    A colleague told me that I have to program the no-caching-command somehow
    within the http header.
    How to do that and does this really solve my problem?

    Stefan


    Tags: None
    • Ewoud Dronkert
      #2
      Re: Disable browser caching

      Stefan Mueller wrote:[color=blue]
      > <meta http-equiv = "pragma" content = "no-cache">[/color]

      For starters, add cache-control and no-store. See
      Useful HTML Meta Tags - cache, no-cache, robots, refresh, content, keywords, description, expires, author, etc.
      http://www.i18nguy.com/markup/metatags.html
      Useful HTML Meta Tags are listed and described, and example usages are given. Links to other resources are also provided.

      Using Firefox 1.5 caching - Mozilla | MDN
      http://developer.mozilla.org/en/docs/Using_Firefox_1.5_caching
      Firefox 1.5 uses in-memory caching for entire Web pages, including their JavaScript states, for a single browser session. Going backward and forward between visited pages requires no page loading and the JavaScript states are preserved. This feature, referred to by some as bfcache (for "Back-Forward Cache"), makes page navigation very fast. This caching state is preserved until the user closes the browser.


      Using http://php.net/header you can send headers more reliably than
      through the meta tag (especially when dealing with proxies).

      --
      E. Dronkert

        Comment

        • Darkstar 3D
          #3
          Re: Disable browser caching

          <?php
          // Date in the past
          header("Expires : Mon, 26 Jul 1997 05:00:00 GMT");

          // always modified
          header("Last-Modified: " . gmdate("D, d M Y H:i:s") . " GMT");

          // HTTP/1.1
          header("Cache-Control: no-store, no-cache, must-revalidate");
          header("Cache-Control: post-check=0, pre-check=0", false);

          // HTTP/1.0
          header("Pragma: no-cache");
          ?>

            Comment

            • Alvaro G. Vicario
              #4
              Re: Disable browser caching

              *** Stefan Mueller escribió/wrote (Sat, 10 Dec 2005 20:22:50 +0100):[color=blue]
              > A colleague told me that I have to program the no-caching-command somehow
              > within the http header.[/color]

              That's correct. As far as I know, proxies do not parse or even read the
              HTML they serve. So HTML is not a good place to give directions :)


              --
              -+ Álvaro G. Vicario - Burgos, Spain
              ++ http://bits.demogracia.com es mi sitio para programadores web
              +- http://www.demogracia.com es mi web de humor libre de cloro
              --

                Comment

                • Michael Winter
                  #5
                  Re: Disable browser caching

                  On 10/12/2005 20:15, Ewoud Dronkert wrote:

                  [snip]
                  [color=blue]
                  > See
                  > http://www.i18nguy.com/markup/metatags.html[/color]

                  It should probably be expressed, more strongly than it has been, that
                  cache- (Expires, Cache-Control, etc.) and content-related (Content-Type,
                  Content-Language, etc.) directives should only be send via HTTP headers.
                  Clients will want to know this information /before/ they start parsing
                  the entity body, and others won't even look there.

                  Trying to substitute HTTP headers (any really, but these especially) for
                  META elements is very questionable.

                  [snip]

                  Mike

                  --
                  Michael Winter
                  Prefix subject with [News] before replying by e-mail.

                    Comment

                    • Stefan Mueller
                      #6
                      Re: Disable browser caching

                      I'm using
                      <?PHP
                      Header('Cache-Control: no-cache');
                      Header('Pragma: no-cache');

                      and that works great.

                      Many thanks
                      Stefan


                        Comment

                        Previous template Next
                        Working...