drupalaficionado.com

Today I downloaded a copy of the Blueprint theme: http://drupal.org/project/blueprint. I had been looking at the blueprint css framework as I have to familiarize myself with it for an upcoming project. As I always do when I find an interesting service or script online, I run to drupal.org and see if it has already been integrated in some way via some contrib module. When I started out with Drupal I got into the nasty habit of building out functionality without checking whether it already existed or not as a contrib module. I've got out of that habit now :).

Anyway - I downloaded and began poking my nose about in the theme files, and in the template.php file I found this beauty:

Fantastic - no more having to click to clear the caches (via the Devel module, or via admin > site configuration > performance). Every time a page is loaded, the cache tables will be cleared.

Here's a full breakdown of drupal_flush_all_caches() from api.drupal.org

Definition

- drupal_flush_all_caches()
- includes/common.inc, line 3627

Description

- Flush all cached data on the site.
- Empties cache tables, rebuilds the menu cache and theme registries, and invokes a hook so that other modules' cache data can be cleared as well.

<?php
function drupal_flush_all_caches() {
  // Change query-strings on css/js files to enforce reload for all users.
  _drupal_flush_css_js();

  drupal_clear_css_cache();
  drupal_clear_js_cache();

  // If invoked from update.php, we must not update the theme information in the
  // database, or this will result in all themes being disabled.
  if (defined('MAINTENANCE_MODE') && MAINTENANCE_MODE == 'update') {
    _system_theme_data();
  }
  else {
    system_theme_data();
  }

  drupal_rebuild_theme_registry();
  menu_rebuild();
  node_types_rebuild();
  // Don't clear cache_form - in-progress form submissions may break.
  // Ordered so clearing the page cache will always be the last action.
  $core = array('cache', 'cache_block', 'cache_filter', 'cache_page');
  $cache_tables = array_merge(module_invoke_all('flush_caches'), $core);
  foreach ($cache_tables as $table) {
    cache_clear_all('*', $table, TRUE);
  }
}
?>

We can see that this clears all cached data on a site, so it's a handy function for module development too.