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I am building a Digg like website in WordPress.

After installing W3 Total Cache, I noticed certain elements such as number of votes (and voters ids) per post are cached even though they shouldn't be (at least not after a user votes for an article). I assume it is not possible to prevent specific elements in a page from being cached (or is it?), so I thought of triggering page cache refresh programmatically.

Any suggestions?

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closed as off-topic by gmazzap, ialocin, birgire, Pieter Goosen, Johannes Pille Aug 24 '14 at 11:51

This question appears to be off-topic. The users who voted to close gave this specific reason:

  • "Your question should be specific to WordPress. Generic PHP/JS/HTML/CSS questions might be better asked at Stack Overflow or another appropriate site of the Stack Exchange network. Third party plugins and themes are off topic." – gmazzap, ialocin, birgire, Pieter Goosen, Johannes Pille
If this question can be reworded to fit the rules in the help center, please edit the question.

if you want to flush the cache you can do that: the plugin has functions for that


flush_pgcache()  //page cache
flush_dbcache()  // database cache
flush_minify()  // minify cache
flush_all() //all caches


and you just need to call it like this:


and that is basically the answer to the question in the title "cache refresh programmatically"

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Great! thank you – user1567 Jan 17 '11 at 21:20
glad i could help! – Bainternet Jan 17 '11 at 22:17
Can you please explicitly define how you instantiated the $w3_plugin_totalcache object? – adamdport Feb 27 '14 at 15:35

W3 Total Cache supports fragment caching. From FAQ:

How do I implement fragment caching? 

Edit your templates to with the following syntax to ensure that dynamic features remain so:

Example 1:
<!-- mfunc any PHP code --><!-- /mfunc -->

Example 2:
<!-- mfunc -->any PHP code<!-- /mfunc -->

Example 3:
<!--MFUNC           -->
                                      echo rand();
<!--/mfunc -->

Example 4:
<!-- mclude path/to/file.php --><!-- /mclude -->

Example 5:
<!-- mclude -->path/to/file.php<!-- /mclude -->
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Thanks Rast. But when I use any of the above examples, I get an error Parse error: syntax error, unexpected '<' – user1567 Jan 17 '11 at 14:34
@user1567 you probably have mismatch with opening/closing <?php ?> tags. I hadn't used these yet so don't have practical snippet to show. – Rarst Jan 17 '11 at 14:57
For one thing, I would like to load functions.php without caching it. The following code in functions.php triggered the error above: <?php <!-- mclude -->require_once(functions2.php)<!-- /mclude --> ?> What is wrong with the code? – user1567 Jan 17 '11 at 15:20
@user1567 according to examples it should be something like ?><!-- mclude -->functions2.php<!-- /mclude --><?php (I think :) – Rarst Jan 17 '11 at 15:36
Thanks for your help. – user1567 Jan 18 '11 at 10:24

Bainternet's solution didn't seem to work for me.

I'm successfully using this alternative snippet within a plugin, loaded at the admin_init action:

// Clear all W3 Total Cache
if( class_exists('W3_Plugin_TotalCacheAdmin') )
    $plugin_totalcacheadmin = & w3_instance('W3_Plugin_TotalCacheAdmin');


    echo __('<div class="updated"><p>All <strong>W3 Total Cache</strong> caches successfully emptied.</p></div>');

Hopefully this helps someone out there.

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I can confirm that kevinlearynet's solution works with W3 Total Cache version It broke for my plugin after that upgrade, and this works a treat. Thank you! Paul. – user9177 Oct 4 '11 at 18:55
I'm trying to run this from the command line. Can I ask how you loaded the W3_Plugin_TotalCacheAdmin class? I tried requiring wp-load.php to no avail. – adamdport Feb 26 '14 at 22:56

To flush a single page by post id in w3tc v0.9.3 I found this worked:

if (function_exists('w3tc_pgcache_flush_post')){
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Where would you place this code? This looks like it runs on every page load (for that ID). Is there no way to prevent to caching completely? – s_ha_dum Mar 20 '14 at 22:31

None of the above worked for me in my plugin. However this worked! Confirmed working for version of w3tc.

if (function_exists('w3tc_dbcache_flush')) { w3tc_dbcache_flush(); }

I did a " $wpdb->get_results( "SELECT sb_settings.f_fb_app_id,sb_settings.f_fb_secret FROM sb_settings" ); " and was surprised the values f_fb_secret and f_fb_app_id was the same every time. It was obviously the w3tc cacheing the result of the query. So I added a dbcache flush in my modify page for the sb_settings table.

Should you want to clear page cache, then just use w3tc_pgcache_flush instead.

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I'd like the downvoter to say why he downvoted. Is there anything wrong in my answer? – Elrinth Apr 12 '13 at 8:19

Use this snippet to make sure your PHP runs regardless of whether caching is on or off. Yes, you have to write/call your function twice.

<!-- mfunc echo 'caching ON'; --><?php echo 'caching OFF'; ?><!-- /mfunc -->

(I think) this is how it works:

  • The mfunc conditionals replace php tags.
  • If caching is OFF, php inside mfunc comments appear in your markup as a HTML comments. <!-- mfunc echo "hello?"; --> Keep this in mind depending on how happy you are for people to see your PHP (only happens when caching is off).
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