It is the successor of the 2.x CacheHelper and allows you to cache your complete views as HTML. No dynamic parts anymore, just complete static content ready to be delivered. If you don't want to set up ESI and other third party caching software, this CakePHP only approach does the job.

It uses a dispatcher and a component. Why not a helper anymore? Mainly because a helper is too limited and would not be able to cache serialized views, e.g. JSON, CSV, RSS content which have been build view-less.

You can install this plugin into your CakePHP application using composer.

The recommended way to install composer packages is:

composer require dereuromark/cakephp-cache

Also don't forget to load the plugin in your bootstrap:

Plugin::load('Cache');
// or
Plugin::loadAll();

You need to add the component to the controllers you want to make cache-able:

public $components = ['Cache.Cache'];

And your bootstrap needs to enable the dispatcher filter:

DispatcherFactory::add('Cache.Cache', [
    'when' => function ($request, $response) {
        return $request->is('get');
    }
]);

The component creates the cache file, the dispatcher on the next request will discover it and deliver this static file instead as long as the file modification date is within the allowed range. Once the file got too old it will be cleaned out. The next complete dispatching process will make the component create a fresh cache file then.

The CACHE constant can be adjusted in your bootstrap and defaults to tmp/cache/views/.

If you need a prefix in order to allow multiple (sub)domains to deliver content in multiple languages for example, use Configure::write('Cache.prefix', 'myprefix') to separate them.

If you only want certain actions to be cached, provide them as actions array. The default cacheTime can be set as global value, but if you want certain actions to be cached differently, use the actions array:

'actions' => ['report', 'view' => DAY, 'index' => HOUR]

In case you want to further compress the output, you can either use the basic built in compressor:

'compress' => true

or you can use any custom compressor using a callable:

'compress' => function ($content, $ext) { ... }

The latter is useful if you want to control the compression per extension.

In case you need to run this before other high priority filters to avoid those to be invoked, you can raise the priority config. You can also adjust the cacheTime value for how long the browser should cache the unlimited cache files, defaults to +1 day.

The Cache shell shipped with this plugin should make it easy to clear the cache manually:

cake cache clear [optional/url]

Using

cake cache info [optional/url/]

you get the amount of currently cached files.

Using

cake cache info /some-controller/some-action/?maybe=querystrings

You can get information on the cache of this particular URL, e.g. how long it is still cached.

In debug mode or with config debug enabled, you will see a timestamp added as comment to the beginning of the cache file.

• It cannot provide partially dynamic parts as the 2.x CacheHelper could. The pages need to be completely cached. So this is most likely a useful caching strategy for non-HTML caches like JSON, XML, CSV, ...
• Make sure you only cache public and non-personalized actions. The dispatcher cannot know if cache files of some non-public actions are requested by an authorized user.

• Limit filename length to around 200 (as it includes query strings) and add md5 hashsum instead as suffix.
• Extract the common file name part into a trait for both component and filter to use.
• Allow other caching approaches than just file cache?
• Allow usage of subfolders for File cache to avoid the folder to have millions of files as a flat list?
• What happens with custom headers set in the original request? How can we pass those to the final cached response?
• Re-implement the removed CacheHelper with its nocache parts?
• Backport to 2.x?