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).

Answer 5

I have written a post on my blog which directly answers this topic. My post covers in detail, how to install the code, how to use the code, and what the code does.

If you read my blog post, you will be able to easily, automatically clear caches on the WordPress action hook: save_post, from the WordPress plugin: W3 Total Cache.

Automatically clear all caches with W3 Total Cache

Example usage of functions:

$this->clear_db_caches();
    Calls the W3TC function: w3tc_dbcache_flush();
    Clears the DB caches completely. Note: Doesn’t clear MySQL Query Cache, just WP based DB caches.
$this->clear_minify_caches();
    Calls the W3TC function: w3tc_minify_flush();
    Clears the minified content caches completely.
$this->clear_object_caches();
    Calls the W3TC function: w3tc_objectcache_flush();
    Clears the object caches completely.
$this->clear_page_caches();
    Calls the W3TC function: w3tc_pgcache_flush();
    Clears the Page Cache completely.
$this->clear_all_caches();
    Calls each of the W3TC functions in one instance.
    Attempts to clear all W3TC caches completely.