W3 total cache - cache refresh programmatically

Question

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?

Answer 1

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 -->

Answer 2

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

<?php 

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:

<?php 
 $w3_plugin_totalcache->flush_all();
?>

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

Answer 3

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');

    $plugin_totalcacheadmin->flush_all();

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

Hopefully this helps someone out there.

Answer 4

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).