A wrapper class for WordPress caching functions.

WordPress provides some caching functions that make it needlessly hard to invalidate previously saved caches. The idea here is to version cache keys by appending a number. So instead of caching something with a key mycache it's cached as mycacheN where N is an integer we increment every time the cache needs to be invalidated (like in save_post hook).

Copy the src/WpCacheHelper.php file to your project and require it require_once('path/to/WpCacheHelper.php');.

Or with composer: composer require andrejcremoznik/wp-cache-helper.

use \AndrejCremoznik\WpCacheHelper\WpCacheHelper as Cache;

function do_something_expensive() {
    $cache = new Cache('data_key');
    $expensive_data = $cache->get();

    if ($expensive_data === false) {
        $expensive_data = get_expensive_data();
        $cache->set($expensive_data);
    }

    return $expensive_data;
}

echo do_something_expensive();

function invalidate_cache() {
    Cache::flush()
}
add_action('save_post',    'invalidate_cache');
add_action('deleted_post', 'invalidate_cache');