Check and clear cache in CodeIgniter with this Output extension

Published on the 22nd April, 2012

I decided to write an extension to the CodeIgniter core Output library as it's great for working with cache but doesn't contain any mechanisms for clearing or managing the cache.

Installation

Download the extension (details below) and extract the MY_Output.php file to your application/core folder. The core output library is loaded automatically so the extension should load automatically too. If you have changed the extension prefix to something other than MY_ in your config.php file you will need to update the extension file appropriately.

Clearing a cached path

You can clear any specified path of its cache by calling $this->output->clear_path_cache('path/to/clear');. This method will return boolean TRUE if successful, FALSE if not.

if ($this->output->clear_path_cache('path/to/clear'))
{
    //Cache has been cleared for 'path/to/clear'
}
else
{
    //Cache not cleared - check file exists / permissions
}

Clearing all cache

You can clear the entire cache directory by calling $this->output->clear_all_cache();.

Note: this will not remove the .htaccess and index.html files in the applications/cache folder.

$this->output->clear_all_cache(); //This method returns NULL

Checking to see if a path is cached

You can check to see if a specified path has been cached by calling $this->output->path_cached('path/to/check'), which will return BOOLEAN TRUE if cache does exist for the path or FALSE if it doesn't.

if ($this->output->path_cached('path/to/check')
{
    //The path 'path/to/check' is cached
}
else
{
    //There is no cache doe 'path/to/check'
}

Checking the expiration time of a cached path

You can check to see when a specified path's cache will expire by calling $this->output->get_path_cache_expiration('path/to/check/). This will return the an INTEGER of the timestamp when the cache is due to expire or BOOLEAN FALSE if there is no cache for the path.

$cache_expires = $this->output->get_path_cache_expiration('path/to/check/');

if ($cache_expires > 0)
{
    //The cache for 'path/to/check' will expire on the unix timestanp $cache_expires
}
else
{
    //There is no cache for 'path/to/check'
}

Download

The project is hosted on github, so you can always download the latest version from there.

License

I added the GNU Public License (GPLv3) to this extension. Read http://opensource.org/licenses/gpl-license.php for more information.

Comments, questions and suggestions

I hope you find this extension useful. If you have any comments or suggestions please leave them in the comments section below. Thanks!

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